Note: Descriptions are shown in the official language in which they were submitted.
~6868~3
Back~round of the_Invention ;~ -
The present invention relates to a novel method of preparing ~;
ethereally substituted monosaccharides from selectively derivatized monosac-
charides. In a further variant, the invention is concerned with an improved
method of partially or fully hydrolyzing the resultant ethereally substituted
monosaccharide derivatives.
Copending Canadian Patent Application Serial Nos. 286,252 and
286,99fl disclose and claim certain ethereal monosubstitutions of monosac-
charides and monosaccharide derivatives. These compo~nds provide important Y -
10 biological signals which allow living cells to resist virus infections. The
compounds are also useful in controlling other types of cell chemistry such
as that involved in the formation of memory. -
The aforementioned compounds carnot be conveniently synthlesized in ~ -
acceptable yield and in sufficiently high purity for pharmaceutical applica-
tions by the most widely accepted method for the synthesis of ethers, i.e., ~ `
Williamson's synthesis. For instance, the Williamson synthesis has severe
disadvantages in the preparation of 3-0-ethers of blocked monosaccharides
such as 1,2:5,6-di-0-isopropylidene-D-glucose due in part ~to the stereochemi-
.:. :. - : . . . .
cal problems which are encountered. The only secondary hydroxyl group avail-
able in 1,2:5,6-di-0-isopropylidene-D-glucose is too sterically hindered to
react at a practical rate with sodium metal to form the sodium salt. Addi-
tionally, the resultant sodium salt is almost insoluble in the solvents com-
monly used in the Williamson synthesis such as ethyl ether or benzene. m e
handling and preparation of the sodium metal required for syn~hesi7ing sub-
~ . .
',, ' '
-3-
:.
68688
stantial quantities of 3-0- ethers of blocked monosaccharides and disposing
of the excess sodium upon complet~ing the reaction also constitute significant ~ ~;
physical hazards.
The second stage of Williamson synthesis, which involves condensa-
tion of an alkyl halide with the sodium salt, is efficient and high yields
ar0 obtained. However, other problems arise when preparing the alkylamino
ethers of monosaccharides. The alkylamino halide which is used in the conden-
sation step must ~e in the form of the free amine and not as the correspond- ~ ;
ing mineral acid salt. Many of the aminoalkyl halides are volatile and very
toxic when in the form of the free amine, but are not when present in the form
o~ a mineral acid salt. An entirely satisfactory method of synthesizing 3-0-
ethers of monosaccharides must therefore be capable of employing the amino-
alkyl halide in the form of the mineral acid salt to avoid the inherent dis- ;
advantages of volatility- and toxicity.
Still another method of condensing organic halides with blocked
monosaccharides is disclosed in United States Patent No. 2,715,121. This ~
method involves autoclaving of the reaction mixture at high temperature under ~` -
steam pressure and, when employed for the preparation of alkylamino ethers of
monosaccharides, low yields of impure reaction products are obtained due to
~0 the preponderance of side reactions and the synthesis of side products. It
is also very difficult to separate a desired substantially pure ether of
monosaccharides from the reaction mixture which is sufficiently free of im-
purities for use in the therapeutic treatment of warm-blooded animals.
In view of the foregoing, it is apparent that the art has long
sought an entirely satisfactory method of preparing ethers of monosaccharides
in high ~ield and purity which does not require hazardous chemicals or
vigorous reaction conditions. However, such a method was not available prior
to the present invention.
It is an object of the present invention to provide a novel method
3Q of preparing ethers of monosaccharides in high yield and purity.
It is a further object to provide a novel method of preparing ;~
ethers of monosaccharides wherein side reactions and side produc~s are almost ~`
- 4 - ~ ;
.~,; :'
, . ., ., . . . .. ... .. . ... , . , ~: . : : ~ .. , : ~ .. . .
~0613~88
absent, and ~hich requires mild reaction conditions and relatively nontoxic
and nonhazardous reactants. ~ :
Still other objects and advantages of the invention will be.apparent .
to those skilled in the art upon reference to the following detailed descrip~
tlon and the examples. .
The Detailed Description of the Invention
Including Presently Preferred Variants Thereof
The method of the present invention for preparing an ethereally sub-
stituted monosaccharide comprises the step of reacting ~-
~1) a monosaccharide derivative having the general formula A-O-H,
wherein O is oxygen, H is hydrogen and A is the residue of a monosaccharide . - .: ~
selected from the group consisting of pentoses, hexoses and heptoses which
has been derivatized with at least one substance selected from the group con-
sisting of tl-a) at least one aliphatic alcohol containing 1-18 carbon atoms ~ :
and preferably 1-4 carbon atoms to produce an acetal group at the site of at ..
least one available hydroxyl residue, ~l-b) at least one aldehyde containing .. . :
1-18 carbon atoms and preferably 1-4 carbon atoms to produce at least one ~
acetal group at the site of at least one available hydroxyl residue, (l-c) at : ; ;
least one ketone containing 1-18 carbon atoms and preferably 1-4 carbon atoms .
to produce at least one ketal group at the site of at least one available .s
hydroxy~l residue, and ~l-d) at least one organic acid residue containing 1-18
carbon atoms and preferably 1-4 carbon atoms to produce an ester group a~ ~he - : -
site of at least one available hydroxyl residue, with .
C2) an organic halide having the general formula Y - ~, wherein X is
selected from the group consisting o chlorine, bromine and iodine and Y is
selected from the group consisting of ~2-a) cyclic monovalent nitrogen con- - .
taining organic radicals and residue, and (2-b) monovalent organic radicals ~.
and residua having the general formula -Rl-B, wherein B is selected from the
group consisting of -X-R2~ -O-R~ and -S-R4, Rl is a divalent organic radical
having a linear carbon chain length of about 1-7 carbon atoms, R2 and R3 are ~
selected from the group consisting of -H, -OH, -SH, halogen and monovalent ~.
organic radicals and residua having a linear carbo~ chain length of about 1-7
- 5 - .`^
''"~ '
~686~3~
- carbon atoms, R4 is selected ~om the group consisting of -H and monovalent
organic radicals and residua having a linear carbon chain length of about 1-7
carbon atoms, M i5 nitrogen, O is oxygen, S is sulfur and H is hydrogen,
to produce an ethereally substituted monosaccharide derivative having the
general ~ormula A-O-~ wherein A and Y are as above defined. The monosac-
charide derivative ~1) and the said organic halide ~2) are reacted at an
elevated reaction temperature while dissolved in a substantially anhydrous
organic solvent in the presence of a solid substantiaily anhydrous strong
inorganic base of a metal'selected from the group consisting of the alkali
metals and the alkaline earth metals.
When R2 or R3 is halogen, the halogen may be F, Cl, Br or I, of
~hich Cl or Br is usually preferred. The organic radical Rl, and R2, R3 and
R4 ~hen they are,organic radicals, may have branched or unbranched linear
carbon chains and may be saturated or unsaturated, and when saturated, the
linear and/or branched carbon chains may contain one or more double or triple
carbon-to-carbon bonds. The linear and/or branched carbon chains of Rl, R2,
R3 and R4 may be substituted or unsubstituted and, when substituted, one or
more substituents ma~ be present, such as -OH, SH, halogen ~F, C1, BT and/or
~), branched or unbranched and saturated or unsaturated hydrocarbon radicals
containing 1-7 and preferably 1-3 carbon atoms, -OR5 and/or -SR5 radicals
~herein R5 is a branched or unbranched and saturated or unsaturated hydro- ,
carbon radical containlng 1-7 and preferably 1-3 carbon atoms, carboxylic
acid re~idua containing 1-7 preferably 1-3 carbon atoms, and amino groups and
aminohydrocarbon radicals containing 1-7 and preferably 1-3 carbon at~ms.
Preferably Rl is a hydrocarbon radical having a linear carbon chain length
o~ 1~3 or 1-4 car~on atoms and R2, R3 and R4 are individually selected from
the group consisting of hydrogen and/or hydrocarbon radicals having linear -
carbon chain lengths of 1-3 or 1-4 carbon atoms.
.',.'.. : . '.
Examples of comyounds from which the aforementioned cyclic radicals
and residua are derived include ~a) monovalent nitrogen containing saturated,
unsaturated or aromatic carbocyclic compounds containing about 4-8 carbon ~ -
atoms in the ring and preferably about 5-6 carbon atoms in the ring and at ;
- 6 - ~ ; ~
'..: '." .~:. :
... . . . , ~ , . . .. - ~ . . . .. . , . .. ~ . . .. . . .
~L~)6~688
least one nitrogen atom attached thereto or to an organo substituent thereon,
(b) heterocyclic organic compounds containing about 3-8 carbon atoms in the
ring and at least one ring nitrogen atom and (c) derivatives of the fore- - :
going compounds wherein at least one substituent is present, such as -OH, :. `.
-SH, halogen (F, Cl, Br and/or I), branched or unbranched and saturated or .
unsaturated hydrocarbon radicals containing 1-7 and preferably I-3 carbon - :
atoms, -OR6 and/or -SR6 radicals, wherein R6 is selected from branched or
unbranched and saturated or unsaturated hydrocarbon radicals containing 1-7
and preferably 1-3 carbon atoms, carbocyclic acid residua containing 1-7 and
10 preferably 1-3 carbon atoms, and amino groups and aminohydrocarbon radioals ~;
.. . .
containing 1-7 and preferably 1-3 carbon atoms. -`~
~he derivatized monosaccharide residue A may exist in open chain
or cyclic forms having, for example, the general formulae:
(a) =I ~ Zl `~
C = (H, OW) ..
G = (H, OW) .
H-O ¦
I = (H, OW)
Z2 ;
' '
(b)
5~\ ~U 7 ~;
(H
O-H
:' `. ' .,
: ':
.
1q~68688
(c) H ~ O Zl
(H, OW ~ ~ H
(H, OW ~ ~ (H, OW)
O-H
wherein Zl and Z2 are selected from -H, -OH, and monovalent hydroxyalkyl,
alkoxyl and/or alkoxyalkyl radicals containing up to about 3 carbon atoms,
W is H or monovalent alkyl, alkenyl, cyclic alkane, cyclic aromatic or acyl
radicals containing 1-18 carbon atoms and preferably 1-6 carbon atoms, or acyl -
containing 1-18 carbon atoms and preferably 1-4 carbon atoms, and at least
one Zl' Z2 or W is other than -H or -OH. Preferably, all reactive -OH pos-
itions with the exception of the -OH position or positions to be ethereally
substituted are derivatized and thus are other than -H or -OH. The above
general formulae illustrate the various isomers of the pentoses, hexoses and
heptoses, the relative spatial configuration of the -H and -OH groups about
the ring and the derivatization thereof in accordance with one presently
.~ .
preferred variant of the invention. The hydroxyl or alkoxyl residue of the ;
hemiacetal or hemiketal linkage may assume an ~ or a~ configuration, and the `
derivatlzed monosaccharides may be in the form of anomers or mixtures of ano~
mers. ;~
The configurations of the ~arious derivatives of isomers of the
20 pentoses, hexoses and heptoses are well known to ~hose skilled in this art and ,;
numerous reference books are available on the subject, the teachings of which -
are incorporated herein by reference. For example Textbook of Biochemistry, I
4th Edition, by West et al (1966) and The Monosaccharides by Stan~k, Cerny,
., ... .. ~, :
Kocourek and Pacak (1963). The prior art discloses, for example, a total of -
eight open chain isomers for the reducing hexoses, and an even larger number ~ ~
of open chain isomers for the reducing heptoses. Either the D-series or the ;
L-series of the pentoses, hexoses and heptoses may be ~ :
,,' ".-.'.'. :. '
8- ` ~
. '' ' ": ' '' "
'.,. :''
~6~36~8
..: :' : '
used in practicing the invention, but it is usually preferred to use the D~
.. ~. .
series. The hexoses often give the best results and especially D-talose,
D-galactose, L_galactose, D-idose, D-gulose, D-mannose, D-glucose, L_glucose,
D-altrose and D-allose The aforementioned pentoses, hexoses and heptoses
may be derivati~ed at one or more of the hydroxyl groups and then ethereally
. : .
substituted at any remaining available reactive position or positions. It
is understood that the ethereal substitution of certain available reàctive
positions of specific monosaccharide derivatives results in more therapeuti-
cally active or less toxic compounds. For instance, the ethereal substitu- `~
tion of the 3-0- position of 1,2-0-isopropylidene-D-glucofuranose or 1,2:5,6- ~ -
di-0-isopropylidene-D-glucofuranose and the 6-0- position of 1~2-0-isopropy-
lidene-D-galactopyranose or 1,2:3,4-di-0-isopropylidene-D-galactopyranose
;.
results in especially valuable compounds.
The following substituents, i.e., Y in the aforementioned general
formula A-0-Y may be ethereally substituted employing an organic halide re-
actant of the aforementioned formula Y - X, on any of the a~ailable reactive
positions of the various isomers of the derivati~ed pentoses, hexoses and
heptoses, to produce nontoxic compounds having exceptional therapeutic activi~y
-(n-propylamino),
-(N',N'-dimethylamino-n-propyl), ~-
-(N~,N~-dimethylaminoisopropyl),
-(Nl-methylpiperidyl), -~
-(N~,N'-dimethylaminoethyl),
-~iN~NI-diethylaminoethyl)~
-(2',N',N'-trimethylamino-n-propyl),
-dimeth~lam no,
-(N',N'-dimethylaminomethyl),
-(N',N'-dimethylaminopropyl), ~`
29 -(N',N'-dimethylamino-iso-butyl)~
_9_ ~ ,~
- .
~:
~6~6~8
,'~ ' `~
-(N',N'-dimethylamino-n-butyl), .~ . :
-(Nt,N'-dimethylamino-iso-pentyl), ,.
-(N',N'-dimethylaminopentyl),
-(N'-methylamino-n~propyl),
-(N'-me~hyl-N'-ethylamino-n-propyl),
-(N',N'-diethylamino-n-propyl), .
-(amino-n-propyl),
-(N'-ethylamino-n-propyl),
- ~'-propylamino-n-propyl), .
:
-(N'~N'-iso-propylamino-n-propyl), ~
-(1',2'-ethylimino-n-propyl), ~''r.
-(l'-n-propylpyrrolidyl),
:~ .
-(1~-n-propylpiperidyl), ., .
,.~ -
-piperidyl, and .
(N',N'-dimethylamino-sec-butyl).
Of the foregoing, -(Nl,N'-dimethylamino-n-propyl) is presently preferred as .. ~;
. ... .. :
Y in the formulae Y - X and A-o-Y and especially when substituted in the :
;available 3-0- position of 1~2-0-1sopropylldene-D-glucofuranose or 1,2:5,6- .`
di-0-1sopropylidene-D-glucofuranose or the 6-0- position of 1,2-0-isopropy-
lidene-D-galactopyranose or 1,2:3,4-di-0-isopropylidene-D-galactopyranose.
The following oompounds of the aforementioned:general formula
A-0-Y have exoeptional wide~spectrum antiviral activity and other thera- `; . ... .
peutioally ~aluable properties, and may be prepared by the method of the ~ -
invention whén employing as reactants the corresponding monosaccharide de~
rivatives A-O_H (or hydrolyzable precursors thereof) and organio halides $- -
Y -- X ~
3-0-3'-(n-propylamino~-1,2-0-isopropylidene-D-glucofuranose, ~ .
3-0-3'-(N',NI-dimethylamino-n-propyl)-1,2-O-isopropylidene-D-
29 glucofuranose, ~ ~
-10- ",:,, ~ ,,
'',"'',.' :''
.~ .
~68688
.................................................................................... ... ...... `.: :. ,. :.
3-0-4'-(N'-methylpiperidyl)-1,2-0-isopropylidene-D-glucofuranose,
3-0-2'-(N',N'-dimethylaminoethyl)-1,2-0-isopropylidene-D-glucofura- ~
nose, ` . ..
3-0-2'-(N',N'-diethylamanoethyl)-1,2-0-isopropylidene-D-glucofura-
nose, ;
3-0-3'-(2',N',Nt_trimethylamino_n_propyl)_1,2_0_isopropylidene-D-
glucofuranose,
3-0-2'-(N',N'-dimethylaminopropyl)-1,2~j6-di-0-isopropylidens-D-
glucofuranose, .
3-0-2l-(N',N'-dimethylaminopropyl)-1,2-0-isopropylidene-D-glucofura -
nose,
6-0-3'-(N',N'-dimethylamino-n-propyl)-1,2-0-isopropylidene-D-
galactopyranose,
6-0-2'-(N',N'-dimethylaminopropyl)-1,2-0-isopropylidene-D-galacto-`~
pyranose, ;~ .
3-0-3'-(n-propylamino)-1,2:5,6-di_0-isopropylidene-D-glucofuranose, ~ :
3-0-3l-(N'~NI-dimethylamino_n_propyl)-1,2:5,6_di 0-isopropylidene- .: -
D-glucofuranose,
3-0-4'-(N~-methylpiperidyl)-1,2:5,6-di-0-isopropylidene-D-glucofura-
nose, ~ :.
3-0-2'-(N',N'-dimethlyaminoethyl)-1,2:5,6_di_0-isopropylidene-D- : -
glucofuranose, ~:
3-0-2'-(NI~Nl-diethylaminoethyl)-1,2:5~6-di-O-isopropylidene-D-
glucofuranose, .
3-0-3'-(2',N',N'-trimethylamino-n-propyl)-1,2:5,6-di-o-isopropyli-
dene-D-glucofuranose,
6-0-3'-(NI,N'-dimethylamino-n-propyl)-1,2:3,4-di-O-isopropylidene- -. -
D-galactopyranose, ~ : :
29 6-0-2'-(N',N'-dimethylaminopropyl)-1,2:3,4-di-0-isopropylidene-D- ~ - .
--11--
''' ' " ''
i~ "' ' .
~6~3~8~3
gala.ctopyranose,
~-NI,N~-dimethylamino-iso-propyl-2,3:5,6-di-0-isopropylidene-D- `
glucofuranoside, and organic and inorganic acid salts thereof.
Additional compounds of the general formula A-0-Y, wherein Y is .
-Rl- ~ 3, which may be prepared by the method of the invention when employing ..
as reactants the corresponding monosaccharide derivatives A-0-H (or hydrolyz-
able precursors thereof) and organic halides Y - X are listed below: ;
Monosaccharide Residue Substituent
(A)~ (Y) -
_ Rl R2 R3
103-0-1,2-0-isopropylidene-D- .j
glucofuranose 3'-n-propyl H methyl : :
" " ethyl " ; ....... :
" 'l H ethyl .. .
" 2'-iso-propyl methylmethyl .. :... :
3'-1,2-propenyl " 1~
" sec-butyl " 'l : : .:
" 3'butyl ll ll 1. -
" 2'ethyl H H ..
~ methyl H H ..
6-0-1,2-0-isopropylidene
-D-galactopyranose 3'-n-propyl H methyl
" ethyl " ;:. : :: .
" H ethyl
" 3~-1,2-propenyl methylmethyl -. . : :- ~ :
2'-iso-propyl " " .
sec-butyl n ,l ~ .
3'-butyl
" 2'-ethyl H H :. -:. .
" methyl H H - t, ,. ,,
203-0-1,2:5,6-di-0-isopropy-
lidene-D-glucofuranose 3'-n-propyl H methyl ::. :.. - :.
n . " ethyl " ::: : :: :.
'l H ethyl .` .... :. .
2'-iso-propyl methylmethyl : :
" 3'-1,2-propenyl " " . :.
" sec-butyl " "
" 3'-butyl ll ll : :
2'-ethyl H H
" methyl H H
6-0-1,2:3,4-di-0-isopropy- . ..
lidene-D-galactopyranose 3~-n-propyl H methyl .~ :
" ethyl ll ~ .
n ll H ethyl :~:
" 3~-1,2-propenyl methylmethyl : -:
" 2'-iso-propyl " "
~ sec-butyl ,l n
29 ~A or a hydrolyzable precursor thereof. .
-12- .. ;
.' '.
...
~6868~ :
Monosaccharide Residue(A)~ Substituent (Y)
~' 3~-butyl methyl methyl
~' 2~-ethyl H H
~ methyl H H
Still other compounds of the general formula A-0-Y wherein Y is a
cyclic monovalent nitrogen-containing organic radical or residue, which may
be prepared by the method of the invention when employing as reactants the
corresponding monosaccharide derivatives A-Q-H (or hydrolyzable precursors
thereof) and organic hàlides Y - X are as follows~
Monosaccharide Residde Substituent
(A)~- (Y)
-- `
Cyclic Radical Substituent on the .
Cyclic Radical ~: ~
3-Q-1,2-0-isopropylidene-D- - .. :
glucofuranose 4'-piperidyl H
3'-piperidyl methyl, H
2'-piperidyl n n
~' 3~-pyrrolidyl
~ 2'-pyrrolidyl
6-0-1,2-0-isopropylidene-D-
ga~actopyranose 4'-piperidyl H : :
3'-piperidyl methyl, H . :~ :
" 2'-piperidyl '~ ll : :
" 3'-pyrrolidyl n " ` . :
" 2~-pyrrolidyl " " `: . :
3-0-1,2:5,6-di-0-isopropy- .: .
lidene-D-glucofuranose~'-piperidyl H ~ .
" 3'-piperidyl methyl, H ..
" 2~-piperidyl " "
ll 3~-pyrrolidyl ~' "
" 2'-pyrrolidyl " " .
6-0-1,2:3,4-di-0-isopropy- .
lidene-D-galactopyranose 4'-piperidyl H :
3'-piperidyl methyl, H
2'-piperidyl
" 3'-pyrrolidyl " "
" 2'-pyrrolidyl
The method of the present invention also provides certain novel :
compounds of the general formula A-0-Y which may be prepared when employing
~A or a hydrolyzable precursor thereof. .
,'' '.': . '
:". ' ~ '
-13-
~ 8688
.
as reactants the corresponding monosaccharide derivatives A-0-H (or hydrolyz- `
able precursors thereof) and the corresponding organic halides Y - X, as ~`~
follows: ;
3-0-2'-(N',N'-dimethylaminoethyl)-1,2-o-isopropylideneglucofuranose,
.:~
3-0-3'-(2',N',N'-trimethylamino-n-propyl)-1~2-0-isopropylidene-
glucofuranose, ~
3-0-21-(N',N'-dimethylaminopropyl)-1,2-0-isopropylideneglucofuranose
~: : . .
6-0-3'-(N',N'-dimethylamino-n-propyl)-1~2-0-isopropylidenegalacto- : :
7.-~ . ~ . -.
pyranose, .
6-0-2'-(N',N'-dimethylaminopropyl)-1?2-0-isopropylidenegalacto- ; ~ .
pyranose, ~ i .3-0-3'-(N',N'-dimethylamino-n-propyl)-1,2:5,6-di-0-isopropylidene- : ; ;.
glucofuranose, ~. . .
3-0-4'-(N'-methylpiperidyl~-1,2:5,6-di-0-isopropylideneglucofuranose ~ . ~
: . -: .
3-0-2'-(N',N'-dimethylaminoethyl)-1,2:5,6-di-0-isopropylidene- ~-
glucofuranose, ~
.,; .. ... . .
3-0-3'-(2',N',N'-trimethylamino-n-propyl)-1,2:5,6-di-Q-isopropyli- .
deneglucofuranose,
. . ... ...
3-_-2'-(N',N'-dimethylaminopropyl)-1,2:5,6-di-0-isopropylidene-
glucofuranose, -.
6-0-3'-(Nl,N'-dimethylamino-n-propyl)-1,2 3,4-di-0-isopropylidene- ~ .
galactopyranose,
6-0-2'-(N',N'-dimethylaminopropyl)-1,2:3,4-di-0-isopropylidene- ~ -
,.' . .; ,' .
galactopyranose,
~ -N',N'-dimethylamino-iso-propyl-2,3:5,6-di-0-isopropylidenegluco-
furanoside, '~
and organic and inorganic acid salts thereof.
The dextrorotatory or levorotatory species of the foregoing novel
..,,, :
:, .:
-14- : :
'. ., .
~8688
compounds may be prepared by the method of the invention by selecting as
reactants the corresponding dextrorotatory or levorotatory monosaccharide
deri~atives A-0-H (or hydrolyzable precursors thereof~, respectively, and the '
corresponding organic halides Y - X.
When the organic halide is an amine, it is preferred to use the
organic acid or inorganic acid salt thereof rather than the free amine, and
especially when the free amine is volatile and/or toxic. Thus, the method
of the present invention is capable of using a non-volatile and/or non-toxic
form of the organic halide as a reactant. mis eliminates the hazards norm- `
ally associated with ~illiamson~s synthesis or similar reactions of this
type.
m e monosaccharide derivative is condensed with the organic halide
in the presence of a solid substantially anhydrous strong inorganic base of
the alkali metals and/or the alkaline earth metals. m e preferred alkali
metals are sodium and potassium, and the preferred alkaline earth metal is
calcium. The inorganic base may be, for example in the form of an oxide or -
hydroxide of the alkali metal and/or the alkaline earth metal. The hydro-
xides are preferred and substantially anhydrous sodium hydroxide usually
produces the best results. Still better results are obtained when the in-
organic base has been heated to an elevated temperature to remove moisture, -
carbon dioxide, or other absorbed substances and thereby regenerate a fresh ~ -
surface. me temperature of heating preferably should exceed 100 C and may
be as high as is necessary to remove the moisture and carbon dioxide and ;
regenerate a fresh surface provided the temperature does not exceed the ~ ;
melting point of the inorganic base. Similarly~ the period of heating should
be sufficiently long in duration to remove the deleterious moisture and/or
carbon dioxide and to regenerate a fresh surface on the inorganic base.
Extended heating normally does not have an adverse effect once the moisture
29 and carbon dioxide are removed. In most instances, the inorganic base may
-15
,
~86~38
be heated at a temperature of approximately 100-200C for about 6-48 hours, ~
and preferably at about 160C for approximately 12-24 hours prior to use. `
It is also advantageous for the inorganic base to be in particulate formJ
such as in the form of pellets, flakes, beadsJ or other small shapes. The
resultant extended surface area seems to aid in promoting the reaction~ The
size of the particles may vary over wide ranges as it is only necessary that
sufficient surface area be presented to promote the reaction. The inorganic ^ ~ ;
base may be, for example, in the form of small thin sodium hydroxide flakes
or 40 mesh sodium hydroxide beads. However, flakes, beads or particles `
several times smaller or larger than this may be employed, such as 1-5 times
smaller or larger. Powdered or pulverized inorganic bases and especially ;
finely powdered or pulverized sodium hydroxide may be used so as to provide
a very high surface area per unit weight.
The inorganic base should be present in an amount of at least 1 -~
chemical equivalent for each mole of the organic halide reactant in instances -
where the organic halide is not an amine salt. In the latter instance, the
inorganic base should be present in an amount of at least 2 chemical equiva- ~-
lents for each mole of the organic halide so as to be capable of reacting -~
with the organic or inorganic acid forming the amine salt and to provide
sufficient excess inorganic base to react with the halide that is released
upon reaction of the organic halide with the monosaccharide derivative. i~
Much larger quantities of the inorganic base than these minimum amounts
.; . , .
may be employed, such as 2-10 or more times the theoretical quantities
.. .. .
required for the aforementioned reactions.
The monosaccharide derivative and the organic halide are
reacted at an elevated reaction temperature while dissolved in a substan-
tially anhydrous organic solvent. Any suitable substantially anhydrous
organic solvent which is inert under the reaction conditions with res-
pect to t~e reactants and the inorganic base may be employed. Examples ;
3Q of such organic solvents include cyclic and open chain ethers containing
- 16 - :
: . , :, , , , ,, , i . . . : ; , .: : : :
-: . - . .. . :,: , .. . ::, .:,.,, .. : , .: . . :: .. . . . . .
368~3
r
about 4 - 8 carbon atoms such as 1,4-dioxane and tetrahydrofuran and ethyl ~
., :, . .
ether, and hydrocarbons, halogenated hydrocarbons and ketones contain m g
about 2-10 carbon atoms such as benzene, hexane, carbon tetrachloride and
acetone. The preferred solvents are 1,4-dioxane and tetrahydrofuran, of
which 1,4-dioxane produces exceptional results. The reactants and the desired -
reaction product should be soluble in the selected solvent and the solvent
should be present in an amount sufficient to dissolve the reactants and the
reaction product. Much larger quantities of solvent may be used such as
1-10 or more times the minimum quantity necessary to effect dissolution of
lo the reactants and the desired reaction product.
The reaction time and temperature may vary over wide ranges. It ` ~
is only necessary to employ sufficiently elevated temperature conditions to - -
effect reaction between the der1vatized monosaccharide and the organic halide
without substantial thermal decomposition, and to allow the reaction to pro- -
ceed for a sufficiently long period of time to reach a desired degree of
conversion. The reaction temperature may be, for example, about 30-150 C
and is preferably about 60-120 C. Usually the best results are achieved at
a reaction temp0rature of approximately 95-105 C. The reflux temperatures
of 1,4-dioxane, tetrahydrofuran, acetone, ethyl ether and carbon tetrachloride
are very satisfac~ory. When desired, the reaction may proceed under super-
atmospheric pressure to allow bigher reaction temperatures to be employed
and especially when using low boiling solvents such as ethyl ether. Atmos-
pheric moisture and/or other extraneous sources of water should not be allowed
to contaminate the reaction mixture for best results. -
The reaction is preferably carried out in the presence of a scav-
enger for water which is inert under the reaction conditions. Any suitable
inert scavenger for water may be employed such as anhydrous calcium chloride,
anhydrous sodium sulfate and the like. Anhydrous calcium chloride is
29 usually preferred. The scavenger is preferably present in an amount suffi-
-17-
. :. , ... :.. :
38
cient to scavenge the water of reaction and/or any additional water which
inadvertently enters the reaction mixture. Much larger quantities may be
present such as l-lO or more times the aforementioned minimum quantity.
The reaction of the derivatized monosaccharide with the organic
halide is allowed to proceed for a sufficiently long period of time to result
in the desired percent conversion. As a general rule, it is preferred that
the conversion be more than 75 % complete and preferably more than 90 % com-
plete. The progress of the reaction may be conveniently monitored by gas
chromatographic analysis and, in such instances, the reaction may be terminated
at the desired percent conversion.
When the reaction is completed, the reaction mixture is filtered to
remove the solid residue which is largely the inorganic base and the scavenging
agent. The filtration step should be conducted in a non-oxidizing atmosphere
and out of contact with an oxidizing gas such as air unless the reaction mix-
ture has first been cooled to a sufficiently low temperature to prevent oxi- -~
dation. It is usually preferred that the hot reaction mixture be filtered
under an atmosphere of an inert gas such as nitrogen, argon or helium directly
into a distillation flask usingaa filter candle or other suitable filtration ~
means to prevent contact with atmospheric air. The solid filter residue may ~ -
be discarded and the various components in the filtrate may be separated by
distillation under reduced pressure. Preferably, the solvent has a boiling
point lower than the reactants and the desired reaction product and, in such
., ~.:
instances, the solvent fraction is recovered first. Upon drying with a des-
sicant such as anhydrous calcium chloride, the recovered solvent may be reus~ed.
After removal of the solvent fraction, usually the unreacted organic halide
fraction distills over followed by an azeotropic mixture of the unreacted
derivatized monosaccharide and the desired product. The azeotropic mixture ~~
is followed by distillation of a final fraction which is the desired product,
. . .
29 i.e., the ethereally substituted monosaccharide.
While the foregoing sequences of steps are preferred in processing -
-18-
88 ~
the reaction mixture to recover the desired ethereally substituted monosac-
charide product, it is understood that other suitable conventional processing
techniques may be employed. However, the aforementioned steps have been
found to be very satisfactory in obtaining the desired product in high yield
and in very high purity. Inasmuch as the products of the invention are useful
as therapeutic agents, high purity is especially important as potentially
harmful side products and other impurities must be kept at a minimum. -
In a further variant of the invention, an hydrolyzable monosaccha-
ride derivative is selected for reaction with the organic halide which has ` 't
the general formula Al-0-H wherein 0 is oxygen, H is hydrogen and Al is the
residue ofaa monosaccharide selected from the group consisting of pentoses,
hexoses and heptoses which has been derivatized with at least one substance
selected from the group consisting of (l-a) at least one aliphatic alcohol
containing 1-18 carbon atoms to produce a hydrolyzable acetal group at the
site of at least one available hydroxyl residue, (l-b) at least one aldehyde
containing 1-18 carbon atoms to produce at least one hydrolyzable acetal
group at the site of at least one available hydroxyl residue, (l-c) at least
one ketone containing 1-18 carbon atoms to produce at least one hydrolyzable
ketal group at the site of at least one available hydroxyl residue, and (l-d)
at least one organic acid residue containing 1-18 carbon atoms to produce an
hydrolyzable ester group at the site of at least one available hydroxyl
~ .. ...
residue. The resultant reaction produces an ethereally substituted mono-
saccharide derivative having the general formula Al-0-Y, wherein Al and
are as above defined and Y is as defined hereinbefore for the organic halide
Y - X. In such instances, Al may be thought of as be~an hydrolyzable -
precurser of A as defined hereinbefore in the compound A-0-Y. The deri-
vatized hydrolyzable monosaccharides Al-0-H may be reacted with the organic
halide under the same conditions and following the same procedures as mentioned
29 hereinbefore when preparing the compound having the general formula A-O_Y.
--19--
,: ,, , . ~ .~
~ ~96~3~8~
~ The ethereally substituted monosaccharide derivative having the -
general formula Al-O-Y may be recovered from the reaction mixture by the steps -~
: . :. ,
set out above for recovering the compound A-O-~. Thereafter, at least one
of the hydrolyzable acetal, ketal and/or ester groups is removed from Al by ~
hydrolysis in an acidic aqueous medium having a pH value less than 7 to pro- ` `
duce an ethereally substituted monosaccharide having the general formula
~2-0-Y, wherein d and Y are as above defined and A2 is the residue of a
monosaccharide corresponding to Al as above defined with at least one of the
said acetal~ ketal and/or ester groups being removed therefrom. In instances
where the acidic aqueous medium has a pH~value of about 3-6 and preferably ~ `~
about 4.0 - 4.5, it is possible to remove only a portion of the sald acetal,
ketal and/or ester groups. When the pH value is less than 3~ such as about
1-2~5, when desired it is possible to remove all of the acetal, ketal and
ester groups from the derivatized -OH positions. The aqueous medium which
is used for the hydrolysis step may be adjusted in pH value by addition of ;
any suitable organic and/or inorganic acid which will result in the desired ~ ~ -
pH value. Mineral acids such as sulfuric acid and hydrochloric aaid are ~;
usually preferred. In 1nstances where the organic halide is an amine, the
resulting hydrolyzed or partially hydrolyzed product is recovered as the ~;
20~ mineral acld salt by lyophilization. me recovered product may be recrysta ~ -
ized from a suitable organic solvent such as methanol to obtain the final ~ ;
pure product. The acidic aqueous medium for the hydrolysis step should be `~ `-
,,,j . . . ..
substantially non-oxidizing with respect to the desired product as oxidized
impurities may be formed.
The hydrolysis step is conducted at an elevated temperature and for -
a sufficièntly long period of time to effect the desired degree of hydrolysis.
For instance, the hydrolysis step may be conducted at the reflux temperature !" ~'',,, ,., '
of the acidic aqueous medium for a period of approximately 6-48 hours, and ~"
29 preferably for about 12-24 hours or until completion of the desired degree ~ -~
-20-
''' ' '' ''
3~061 3ti,~8 ~:
. ~ .
of hydrol~sis as indicated by monitoring the progress of the reaction by gas
chromatographic analysis. In the latter instance, the hydrolysis is termin- -
ated when the analytical data indicate the disappearance of a peak due to
the starting compound and the appearance of new peak which is indicative of
~: ! ' ' ' .
the desired hydrolysis product. Thereafter, the aqueous solution ~ay be
cooled and the pH value adjusted to above 6.0, and preferably to about 6.5,
and lyophilized. The resultant desired hydrolysis product is precipitated
and recovered in the form of crystals which may be purified by recrystalli=a-
tion from organic solvents as aforementioned.
It is understood that the preparation o~ ~mple derivatives of the -`
compounds described herein 1S embraced by the method of the invention. Such
derivatives may be prepared by prior art techniques and procedures. For
example, the free amine compounds are basic and form organic acid salts and
inorganic acid salts. The salts may be prepared by the usual prior art
techniques, such as by adding the free amine compound to water and then adding
the desired organic acid or mineral acid thereto in an amount sufflcient to
neutralize the free a~ine. Examples of suitable acids include HCl, HBr,
H2S04, HN03, benzoic acid, p-a~inobenzoic acid, p-aceta~idobenzoic acid, p-
hydroxybenzoic acid, alkane sulfonic acid, p-toluene sulfonic acid, acetic
acid, alkylcarboxylic acids, oxalic acid, tartaric acid, lactic acid, pyruvic
acid, malic acid, succinic acid, gluconic acid and glucuronic acid. The
aqueous solution of the resulting salt may be evaporated to the volume
necessary to assure precipitation of the salt upon cooling. The precipitated
salt is recovered by filtration, washed and dried to obtain a inal amine salt
product. m e amine salts are often preferred for use in formulating the
therapeutic compositions as they are crystalline and relatively nonhygroscopic. ~ -
The amine salts are also better adapted for intramuscular injection than are
the free amines.
29 Prior art blocking techniques may be employed for derivatizing the ;~
-21-
~6~316813 ~ .~
: ; ~
.. . .
monosaccharide to be reacted with the organic halide such as acetonization `
and acetylation. ~uitable prior art blocking methods are described in
United States patent ~2,715,121 and in the specific examples appearing
hereinafter. In instances where an aldehyde or ketone is reacted with
hydroxyl groups on adjacent carbon atoms, the initial compound may be dis-
solved in the desired aldehyde or ketone under anhydrous conditions and a ;
Lewis acid catalyst may be added in a catalytic quantity, such as 1 % zinc
chloride or anhydrous phosphoric acid. Often acetone is the preferred
blocking agent, but aldehydes or ketones of much higher molecular weight may
be used when desired such as those containing up to 25 carbon atoms. me
reaction mixture may be agitated at room temperature for a prolonged reaction -
period such as 24-48 hours. m e compound may be blocked in a plurality of
positions, such as the 1,2-and/or 5,6- positions.
It is also possible to block one or more free hydroxyl positions
of the compound with an ester group, wherein the carboxylic acid residue
contains 1-18 and preferably 1-3 carbon atoms. m e ester derivatives like- ~ -
wise may be prepared following prior art techn~ques such as by reacting a
,, .
carboxylic acid anhydride with the compound following prior art practices. ~
. .
Additionally, the ~ or~ alkyl derivatives of monosaccharide derivatives such
as 2,3:5,6-di-0-isopropylidene-D-glucofuranoside may be prepared following
prior art techniques. In this latter instance, the compound is dissolved
'.J ' ;' ~ '
in a dry alcohol having the desired carbon chain length with aforementioned
residua and reacted with the compound in the presence of a catalyst such as
the hydrogen chloride of Dowex~ 50 H+ resin. While the above discussed
derivatives are presently preferred, it is understood that still other sim-
ple derivatives may be prepared following prior art techniques and then
used in practicing the present invention. In addition to the foregoing, ~ ~
the compounds may also include monosubstitutions of monosaccharide deriva- ~ -
29tives in which the substrate Y may be replaced by a substituent R8 wherein -
~Trademark -22- -
.. .. . .. . . . . .. . ..
10613688 .~
R8 is a deoxymonosaccharide derivative of halogen, keto, amino, lower alkyl,
mercapto, alkenyl, aIkynyl, aromatic, heterocyclic or alkylcarboxylic acid
and its derivatives. R8 may also represent the same groups as the above
substrate of the monosaccharide derivative ethers. Still other compounds
have a general formula A-0-Y wherein Y is -Rg-S-Rlo where Rg is a saturated
or unsaturated hydrocarbon radical containing 1-7 carbon atoms and Rlo is a
monovalent saturated or unsaturated hydrocarbon radical containing 1-7 carbon
atoms and hydrogen.
m e compounds prepared by the method of the invention are especially
useful as wide spectrum antiviral agents for the therapeutic treatment of
warm-blooded animals. They exhibit potent antiviral activity against both
RNA and DNA viruses, contrary to the prior art antiviral agents. The com-
pounds exhibit marked suppression of virus particle multiplication and virus
induced cell injury in animal and human cell tissue culture systems against
such widely varying viruses as herpes simplex, influenza A, mumps, poliovirus "
and rhinovirus.
The following specific examples further illustrate the present
invention.
Example 1
To a solution of 104 g (0.4 mole) of 1,2:5,6-di-0-isopropylidene- ~ `
D-glucofuranose in 550 ml of 1,4-dioxane was added 189.7 g (1.2 mole) of
3-chloro-NjN-dimethylamino propane in the form of the hydrochloride salt and
144 g (3.6 mole) of sodium hydroxide. The suspension was mechanically
stirred and heated to reflux for 18 hours. m e reaction mixture thus pre-
pared was filtered the solids were washed with 1,4-dioxane and the washings
were combined with the filtered liquid. The solvent was removed under re-
duced pressure and an amber-colored viscous oil was obtained.
The oil was distilled under high vacuum (less than 1 mm Hg) while
29 using a very slight dry nitrogen purge to obtain high and low boiling
-23-
.~ ~
"
8~
fractions. The low boiling fraction was identified as unreacted 3-chloro-N,
N-di-methylamino propane. The high boiling fraction had a boiling point of
148-154 C at 2.5 mm Hg and was a clear viscous oil with an optical rotation
f ~D 5 ~ -19.3 neat (100 mm) and a density of 0.95 g/cc. The refractive
index was~ D 6 = 1.4576. Gas chromatography showed a purity greater than
99 %, An elemental analysis showed: C, 59.13; H, 8.99; N, 4.12; 0, 27.7.
The yield was 80 % of the novel compound 1,2:5,6-di-0-isopropylidene-3-0-3'-
(Nt,N'-dimethylami~o-n-propyl)-D-glucofuranose.
A portion of the above oil (10 g) was hydrolyzed in aqueous sulf-
uric acid at a pH value of 1.9-2.1 for 10 hours with refluxing. The result-
ing solution was adjusted to a pH value of 4.5 with saturated Ba(OH)2 solu-
tion, centrifuged, and filtered through an ultrafine filter. The filtrate
was lyophilized to a white-to-slightly yellow solid having a melting point ;;~
of 78-80 C. Gas chromatography data indicated above 99 % purity of the novel
compound 3-0-3l-(NI,Nl-dimethylamino-n-propyl)-D-glucopyranose. In thin-
layer chromatography, the flow rate on silica gel with a solvent mixture com-
posed of n-propanol, ethyl acetate, H20 and NH3 in the ratio by volume of
60:10:30:10, respectively, was Rf = 0.356.
A portion of the oil is partially hydroly~ed to 1,2-0-isopropyli-
dene-3-0-3l-(NIjNl-dimethylamino-n-propyl)-D-glucofuranose by dlssolving it
in distilled water and adjusting the pH of the approximately lM solution to
3.0 + 0.2 with 6N HCl. The solution is extracted twice~with chloroform and --
the clear aqueous solution is refluxed for about two hours. Completion of ~;~
partial hydrolysis reaction was monitored by gas chromatography ~rom dis-
appearance of the peak of parent compound and appearance of a new peak with
larger retention time. m e solution is then cooled, made alkaline with 30 %
sodium hydroxide to pH 10.5 and then extracted with chloroform. The chloro-
form phase is separated, dried over anhydrous magnesium sulfate and vacuum
9 distilled to remove the solvent. The resulting colorless viscous oil has
-24-
1~68~;88
optical rotation of ~ t = -12 and refractive index of 1.4687 at 25C.
Alternatively, the compound can be obtained as hydrochloride salt by lyoph-
ilizing the aqueous solution after partial hydrolysis at pH 4.0-4.5. A
white crystalline material is obtained which is recrystallized from methanol.
The crystalline hydrochloride of 1,2-0-isopropylidene-3-Q-3~-(N',N'-dimethyla-
mino-n-propyl)-D-glucofuranose has a melting point of 181-183 C and purity `
as indicated by gas chromatography is 98+ %. Infrared spectrophotometry in-
dicates presence of strong -OH band which is not presen~ in parent oil. The
elemental analysis for the hydrochloride salt in a typical batch showed: C,
49.09; H, 8.40; N, 4~14, Cl, 10.32; O, 28.12. Theoretical values are as
follows: C, 49.19; H, 8.19; N, 4.09; Cl, 10.39; O, 28.11.
The gas-liquid chromatograms for the above intermediate and final
novel compounds were run on a Beckman GC, Model 72-5 with a hydrogen flame
detector. m e column used for the intermediate novel compound was a com-
mercially available SE-52 column, wherein methyl phenyl resins act as stat-
ionary phases supported on Chromosorb W (H.P.) which is made by Johns-Manville
Corporation. The final novel compound was chromatographed on a Chromosorb
103 glass column, which is packed with porous resins. The foregoing mat-
erlals are commercially available.
Example 2
Starting with 51 g (0.3 mole) of 4-chloro-N-methyl-piperidine
hydrochloride and 26 g (0.1 mole) of 1,2:5,6-di-0-isopropylidene-D-glucofura--
nose and 36 g of NaOH in 150 ml 1,4-dioxane, condensation was accomplished
using the general procedure outlined in Example 1. m e residue remaining
following vacuum distillation was dissolved and recrystallized from hot
methanol. The melting point was 106-107.5 C (sharp).
Hydrolysis of the above product in H2S04 at a pN value of 2.1
yielded 3-0-4~-(N'-methylpiperidyl)-D-glucopyranose having an optical rota-
29 tion of ~(~D 5 = ~38.42 in H20. A gas chromatography analysis in accordance
-25-
'.'.' ~'
6~ 88
with Example 1 indicated that the purity of the product was in excess of
96 %. The melting point was 62-65 C. :
Example 3
A solution of 0.1 mole of 1,2:5,6-di-0-isopropylidene-D-glucofura-
nose in 50 ml of tetrahydrofuran was added to a suspension of 0.3 mole of
2-chloro-N,N-diethylaminoethane hydrochloride and 36 g of sodium hydroxide -
in 100 ml of tetrahydrofuran. The suspension was mechanically stirred and
refluxed overnight and the reaction mixture was treated as set out in -
Example 1. The desired product, 1,2:5,6-di-0-isopropylidene-3-0-2'-(N',N'-
diethylaminoethyl)-D-glucofuranose was obtained as a clear yellow liquid
(bolling point 144-150 C/0.15 mm Hg) having an optical rotation of ~D 8 =
-20.6 neat and a refractive index of~ D 5 = 1.4532. The liquid solidified
on exposure to air, probably due to formation of the carbonate salt, The
yield was 85 %. -
Ten grams of the above product were h~drolyzed with aqueous sul-
furic acid at a pH value of 1.9-2.1 for ten hours under reflux. m e result-
ing solution was adjusted to a pH value of 4-5 with satorated barium hydrox-
ide solution and then centrifuged and filtered. Lyophili7ation of the ;-- ~
filtrate yielded 6.55 g of light brown crystalline 3-0-2'-(N',N'-diethylamin- ;
oethyl)-D-glucopyranose. m e optical rotation in water was ~ }D = +36.33 . ;
A gas chromatogr~phy analysis in accordance with Example 1 indicated that
the purity was in excess of 99 %.
Example 4
To 26 g (0.1 mole) of 1,2:5,6-di-0-isopropylidene-D-glucofuranose
and 36 g (0.9 mole) of sodium hydroxide in 150 ml of refluxing tetrahydro- ;~
furan was added dropwise over one hour 0.3 mole of 3-bromopropionitrile in
50 ml of tetrahydrofuran. m e reaction mixture was refluxed for an additional
six hours and then filtered. The solids were washed with tetrahydrofuran
29 and the washings were combined with the filtrate. The solvent was removed
-26-
:
' :, '' ' ' ' ,' "'':, , '' " ' " " ' ".',' . ;' ::'; ' "';'' ,''' ' ",' ' ' ,:.'' '' " ':"; ' ' '
~6~36~
under reduced pressure and solid 1,2:5,6-di-0-isopropylidene-3-0-3~-propioni-
trile-D-glucofuranose was obtained. m e decomposition point was 165 C and it
was light sensitive indicating utility in photographic applications. ;~
Five grams (0.016 mole) of the above product was dissolved in
anhydrous ether and added dropwise to a suspension of 0.76 g (0.02 mole)of
lithium aluminum hydride in ether. The resulting complex was dissolved in
cold hydrochloric acid and neutralized rapidly with sodium bicarbonate. The
suspension thus produced was extracted with chloroform and the solvent was
removed to obtain a yellow oil in a yield of 2S0 mg. Gas chromatography in
lo accordance with Example 1 indicated a purity of 98 % and there was a sharp
infrared band at 3400 cm . The oil was hydrolyzed at a pH value of 2.1 in
sulfuric acid and lyophilized to dryness. The yield was 85 mg of 3-0-3'- -
(n-propylamino)-D-glucopyranose.
Example 5
m e 3-0-2'-(N~,N'-dimethylaminopropyl) derivative of 1,2:5,6-di-0~
isopropylidene-D-glucofuranose was prepared by condensing 0.1 mole of 1,2:5~6
"
_di-0-isopropylidene-D= glucofuranose with ~.3 mole of 2-chloro-N,N-dimethy-
lamino propane hydrochloride in the presence of 0.9 mole of sodium hydroxide
in 150 ml of 1,4-dioxane. m e reaction mixture was fractionally distilled; `
under reduced pressure to obtain a yellow viscous oil (boiling point 142-
14S C/0.07 mm Hg) in 81 % yield. m e optical rotation was ~D25 = -21.5
neat and the refractive index was ~D = 1.4549. Gas chromatography in
accordance with Example 1 indicated only one component.
The above prepared yellow viscous oil (10 g) was hydrolyzed uith
aqueous sulfuric acid at a pH value of 2.0 by refluxing for 10 hours. m e
pH value of the hydrolysa~éewas adjusted to 4-5 with saturated barium hydro-
xide solution, filtered and lyophilized to obtain 10.5 g of light yellow
crystals of 3-0-2'-(N',N' -dimethylaminopropyl)-D-glucopyranose. The optical
29 rotation in water was ~ ~D = +37.86 . Gas chromatagraphy in accordance :
~7-
'',.:' ' ' ' . :.''.~:
with Example 1 indicated a purity in excess of 82 %.
A portion of the oil, 1,2:5,6-di-0-isopropylidene-3-0-2~-(N~
dimethylaminopropyl)-D-glucofuranose, is partially hydrolyzed at pH 3.0 + ;
.~.,,
0.2 as indicated in Example 1. A white crystalline hydrochloride salt is
.
obtained on lyophllization. m e salt obtained is highly hygroscopic, with ;
gas chromatographic purity being of the order of 80 %.
. . .
Example 6 ;~
To 0.1 mole of 1,2:5,6-di-0-isopropylidene-D-glucofuranose was added
0.3 mole of 2,N,N~trimethylaminopropyl chloride hydrochloride along with
lo 36 g of sodium hydroxide. The general reaction procedure was in accordance
with Example 1. m e oil resulting from the reaction had a boiling point of
144-146 C at 0.6 mm Hg and an optical rotation of ~oc~D = -20.05 neat.
The above product was hydrolyzed according to the general method
outlined in Example 1 to obtain the desired 3-0-3'-(2',N',N'-trimethylamino-
n-propyl)-D= glucopyranose. The optical rotation of the product in water was
~~ 20 = +38Ø
A portion of the oil, 1,2:5,6-di-0-isopropylidene-3-0-3~-(2',N',N'-
trimethylamino-n-propyl)-D-glucofuranose, is partially hydrolyzed at pH 3.0
+ 0.2 according to the procedure mentioned in Example 1. A white crystalline
20 1,2-0=isopropylidene-3-0= 3'-(2',N',N'-trimethylamino-n-propyl)-D-glucofura-
nose hydrochloride was obtained which is highly hygroscopic in nature. Opti- `
cal rotation of the hydrochloride salt at pH 7.0 and 25 C lS -21.33 . Gas
chromatography analysis indicated better than 99 % pure major component.
Exam~le 7
Using the general method outlined in Example 1, 0.02 mole of
1,2:5,6-di-0-isopropylidene-D-glucofuranose in 1,4-dioxane was reacted with -
0.0225 mole of 2-(2-chloroethyl)-N-methylpyrrolidine hydrochloride and
0.0675 mole of sodium hydroxide. After 18 hours the solvent was removed and
. :. . -:
29 the resulting orange oil was vacuwn distilled under nitrogen. The residue
-28-
868~3
consisted of the desired product, 1,2:5,6-di-0-isopropylidene-3-0-2'-
{2"-(N"-methyl)-pyrrolldyl3-ethyl-D-glucofuranose having an optical rotation
of {a~D ~ -22.95 in chloroform.
Example 8
1~2:5,6-di-0-isopropylidene-D-glucofuranose (0.1 mole) and N-(2-
chloroethyl)-pyrrolidine hydrochloride (0.15 mole) are mechanically stirred `~
and refluxed with 0.45 mole of sodium hydroxide in 150 ml of tetrahydrofur~n
for 18 hours. The tetrahydrofuran is removed from the reaction products and
the resulting oil is vacuum distilled under nitrogen. The 3-0-2' ~ Nt-(pyrro-
lidyl)-ethyl~-1,2:5,5-di-0-isopropylidene-D-glucofuranose de'rivative has a "-
boiling point of 165-1~1 C/0.15 mm Hg. Gas chromatography indicates a purity ~"
.. '.
~f 99 %. Using the hydrolysis procedure outlined in Example 1, 10 g of the
blocked oil was hydrolyzed and lyophilized giving a white ~ygroscopic crystal- ~
line solid. ''
Example 9
The N',N~-dimethylamiDo-n-pentyl derivative of 1,2:5,6-di-0-iso- ' ~ '
propylidene-D-glucofuranose is made by condensing N,N-dimethylamino-n-pentyl- '~ ;
5-chloride hydrochloride with 1,2:5,6-di-0-isopropylidene-D-glucofuranose in
,~
the presence of pulverized sodium hydroxide in freshly purified, dry 1,4- ~ ~ ~
dioxane as described in procedure in Example 1. The product was confirmed . ' "
by gas chromatography and infrared spectra. '~
N,N-dimethylamino-n-pentyl chloride hydrochloride is Dade from j' ' '
commercially avaiIable sample of N,N-dimethylamino-n-pentyl alcohol by treat~
ment with thionyl chloride (SOC12). Specifically, 10.7 g of thionyl chloride '' ' '
in a 250 ml three neck round bottom flask is cooled in a salt-ice water bath ''~
and stirred vigorously. To the cooled solution is added~ dropwise, 10 g of ;'' ~ ~ '
N,N-dimethylamino-n-pentyl alcohol. The reaction is exothermic and tempera- ;
ture is careful'ly controlled. The mixture is stirred for one hour after the '
29 evolution of S02 and HCl subsides. The mixture is brought to room tempera- ' '
-29- ~ ~ ~
.' '.' ' .
. ! ' . ' :'
38
ture and allowed to stir overnight. Absolute alcohol is added to destroy
excess thionyl chloride. Ten grams of crude N,N-dimethylamino-n-pentyl ;
chloride hydrochloride is obtained as a white solid. This is used directly
Por the condensation reaction with 1,2:5,6-di-0-isopropylidene-D-glucofura~
nose without further purification. The alcohol and chloride can be resolved
on Chromosorb 103 gas chromatography column.
Example 10
Bromine (9.8 g) was added slowly and dropwise to a mechanically
stirred mixture of 50 g cracked ice and a chilled aqueous sodium hydroxide ;
solution (7 g/20 ml water). After the addition of bromine is complete, 15 g ~ -
of 1,2:5,6-di-0-isopropylidene-3-0-acetamido-D-glucofuranose (prepared by the
general procedure outIined in Example 1 by the condensation of 1,2:5,6-di-_-
isopropylidene-D-glucofuranose with 2-chloroacetamide in the presence of
sodium hydroxide)is added in four portions 15 minutes apart. The reaction
mixture is heated for one hour in a water bath. After this time an additional
aqueous solution of sodium hydroxide (20 g/20 ml) is added and heating is con- -
tinued for another hour. m e mixture is cooled and extracted three times
with ether. The ether extract is dried over anhydrous magnesium sulfate.
m e yellow hygroscopic solid remaining after evaporating off the ether is the
desired 1,2:5,6-di-0-isopropylidene-3-0-aminomethyl-D-glucofuranose deriva-
tive. The product was identified by the disappearance of the carbonyl ~-
stretching at 1670 cm found in the parent acetamido compound.
Example 11
Well established methodology of prior art was employed to determine `
the antiviral p~tency of derivatives of 1,2-0-isopropylidene-D-glucofuranose -
.. :.: . .
HCl against poliovirus, type 1, and rhinovirus, type lA, in tissue culture
at 37 C, employing HeLa cells with an agar overlay and WI-38 cells respect-
ively. (See Wallis, C., F. Morales, J. Powell, and J. L. Melnick, Plaque -
29 enhancement of enteroviruses by magnesium chloride, cysteine, and pancreatin.
-30-
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1~6~3688
J. Bacteriol. 91:1932-1935, 1966). Poliovirus cell injury was determined
by the study of plaque formation and rhinovirus was examined for cytopathic
effect. In Table I, the virus inhibiting effects of three concentrations of
the 3-_-3l-(N~,N~-dimethylamino_n-propyl) derivative;,are depicted. m e re- ;
sults are given as the degree of inhibition of infectivity, identified as
plaque formation in the poliovirus system and as cytopathic effect in the
system studying rhinovirus. Our results indicate that, at the appropriate
dose, drug can completely inhibit lOOO plaque forming units (PFU) of polio- `
virus and a 1000 TCID50 dose of rhinovirus lA, a virus dose 1000 times that -l;
amount required to kill ~O % of the tissue cultured cells.
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Example 12
Derivatives of 1~2-0-isopropylidene-D-glucofuranose hydrochloride
were examined for their capacity to suppress influenza A2 disease in mice
and for their capacity to suppress death and nonlethal nervous system disease
produced by the encephalomyocarditis virus in mice. In these studies, drug
effect on lung, pathology produced by a 15 ID50 dose of influenza virus was
examined. This dose is 15 times the dose that produces disease in S0 % of
the animals. Disease and drug effect on disease were determined by lung
weight increase and reduction thereof. In the encephalomyocarditis study, 10
times the dose capable of killing 50 % of the animals was given, and the
degree of nonlethal disease and death were determined7 as well as drug ln-
hibition of both of these parameters. m e results for these experiments are
summarized in Table II, and indicate the production of signiflcant reductlon ~;
in lung weight increase by drug, as well as a slgnificant ir~ibition of death
and nonlethal disease produced by encephalomyocarditis virus. These effects
were more potent for the 3-0-3'-(N',N'-dimethylamino-n-propyl) derivative
: ,
than for the other two derivatives studied.
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Example 13
This example illustrates the preparation of 1,2:5,6-di-0-isopropyli- "
dene-3-0-21-(NI,N~-trimethylamino-n-propyl)-D-glucofuranose.
To 104 g (0.4 mole) of 1,2:5,6-di-0-isopropylidene-D-glucofuranose
were added 0.6 mole of 3-chloro-~,N-2-~trimethylpropylamine chloride hydro-
chloride, 1.8 moles prebaked sodium hydroxide beads, 10 g of anhydrous magne-
sium sulfate, and 500 ml of dry 1,4-dioxane in a 3-necked 3 liter reaction
flask fitted with a mechanical stirrer and a reflux condenser. The reaction ;
mixture was stirred vigorously and refluxed for about 20 hours. me progress ~-
of the reaction was monitored by gas chromatographic analysis. m e reaction , ;
mixture was allowed to cool then filtered, and the dioxane solvent and un-
reacted amine were removed from the filtrate under reduced pressure with a ; ;
rotary evaporator. A colorless to slightly yellow viscous oil (135 g) was
obtained on fractional distillation at 144-146C at a pressure of 0.6 mm Hg.
m e oil had an optical rotation of [~] neat 100 mm HG = -20-05- The ~ `
yield was more than 85 ~.
Example 14 'r.; ,'. '' "' '
,,~'`".'' ' ''
This example illustrates the preparation of 1,2:5,6-di-0-isopropy-
lidene-3-0-3'-propanol-D-glucofuranose.
To a 3~-necked reaction flask fitted with a mechanical stirrer and a
reflux condenser were added 52 g of 1,2:5,6-di-0-isopropylidene-D-glucofura- `
nose, 25 g of 3-chloropropanol, 24 g of sodium hydroxide, 5 g of anhydrous
calcium chloride and 250-300 ml of dry 1,4-dioxane. The reaction mixture ~ ;
was gently refluxed for 16 to 20 hours and was monitored by gas chromato-
graphy. The solvent and unreacted 3-chloropropanol was removed by fractional ~ `
distillation. The yield was more than 70 ~
A si~ilar reaction was run in an autocla~e under steam pressure.
m e yield was lower and deep brown-red impurities were formed which were
29 difficult to isolate by chemical steps or column chromatography.
-35-
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Example 15
This example illustrates the preparation of 1,2:5,6-di-0-isopropy- ;
lidene-3-0-methylthiomethyl-D-gl-ucofuranose.
" .
A reaction mixture containing 52 g of 1,2:5,6-di-0-isopropylidene- .
D-glucofuranose, 58 g of chloromethylmethylsulfide, 48 g of baked sodium
hydroxide and 200 ml of dry tetrahydrofuran was refluxed overnigh~ with --
efficien~ mechanical stirring. The mixture was filtered, then dried and the
solvent was removed under reduced pressure. On fractional distillation, the
fraction boiling between 140C and 148C at 0.1 mm Hg pressure was collected `~
as a yellowish oil. The oil also contained some unreacted, 1,2:5,6-di-0- -
isopropylidene-D-glucofuranose. The latter was removed by selective crys~al-
lization from hot hexane solution. The final product was a yellov oil having `
an optical rotatiOn of [~ neat, 100 mm Hg
Example 16
A solution of 26.0 g of lj2:3,4-di-0-isopropylidene-D-galactopyra-
nose ln 50 ml of anhydrous THF was mixed with a suspension of 0.3 mole of -
3-chloro-N,N-dimethylamino propane hydrochloride and 36 g of sodium hydroxide
in 100 ml THF. The mixture was stirred vigorously and refluxed ~r three
hours. The resulting brownish solution was cooled, filtered and most of
the solvent was evaporated leaving a brown oil. The remaining solvent and
unreacted 3-chloro-N,N-dimethylamino propane were removed by fractional dis- `
tillation under reduced pressure. The residual oil was extracted with ~-~
chloroform, decolorized with activated charcoal and dried over anhydrous
magnesium sulfate. Removal of the chloroform solvent yielded 13.4 g of
yellow oil, which was identified as 1,2:3,4-di-0-isopropylidene-6-0-3~-
(Nl,NI-dimethylamino-n-propyl)-D-galactopyranose. Infrared and gas chromato-
graphy in accordance with Example 1 indicated the presence of one major
component having a refractive index of`~D = 1.461 and sn optical rotation
29 f ~} D = ~49-4 in chloroform.
-36-
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The oil was refluxed with 50 ml of 0.5 N sulfuric acid for 18
hours. The resulting solution was washed with chloroform and the pH value
was adjusted to 4.2. On lyophilization, the aqueous solution yielded 4.67 g `
of white crystalline solid 6-0-3'-(N',N'-dimethylamino-n-propyl)-D-galacto-
pyranose having an optical rotation of [~]D 5 = +77.2 in H20. A gas chroma-
tography analysis in accordance with Example 1 indicated that the purity of
the product was in excess of 95 %.
Example 17
This example illustrates the preparation of 6-0-2'-(N',N'-dimethyl-
aminopropyl)-D-galactose.
The general procedure of Example 2 was followed with the exception ~
of using 2-chloro-N,N-dimethylaminopropane hydrochloride as a starting , ; ;
material rather than the corresponding 3-chloro derivative. The intermediate --
product had an optical rotation in water of [c~]D 24= _54.5 , and a refractive
index of~ D 4 = 1.4552. The final product had a rate of flow value on thin
layer chromatography analysis in accordance with Example 1 of Rf = 0.376.
Examp~e 18
The most potent of the above derivatives, 3-0-3'-(N',N'-dimethyla-
mino-n-propyl)-glucose was examined for its capacity to suppress influenza
A2/Hong Kong disease in mice. In this study mice were infected by a sub- ` `
~leth~,disease-producing dose of mouse-adapted human influenza virus and were
treated either with distilled water (control) or with 40 ~mg/Kg compound.
Fifty percent of the administered drug was in a form reduced in hydrophili-
city by addition of the labile organic group acetone to the 1,2-positions
to promote absorption into cells and slow release from body fat. Medication
was administered orally, beginning 24 hours post-infection. Disease progres~
sion and drug effect were evaluated at 8 days by examinakion of the lung
:~
for pneumonic consolidation, after the method of T. W. Chang and L. Weinstein :
29 (Am. J. Med. Sci., 1973, in press) and by objective technic of weighing
-37-
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.
1~68688
the lungs. Note tha~ lung weight increase during influenza infection re-
flects edema, hemorrhage and virus content (see P. Gordon and E. R. Brown,
Canad. J. Micro. 18:1463, 1972). Below in Table 3, part A, we presen~ the
objective data for lung weights illustrating an 82 % suppression of disease ~
by our derivative. ; - -
The above medication was also examined for its capacity to prevent
death in mice ill with a lethal influenza A/PR/8 infection. The drug was - -
given subcutaneously at 3 dose levels, once 90 minutes before infection. The ~ ;
results illustrate a significant dose-dependent protection against death and
ar~ shovn in Table 3, psrt b.
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Example 19
Well established methodology of prior art was employed to determine
the antiviral potency of compounds against influen3a A2 virus, Hong Kong
strain, in tissue culture, employing the baby hamster kidney cell line ~see ~ ~ -
R. L. Muldoon, L. Mezny and G. G. Jackson in Antimicrobial Agents and Chemo~
therapy 2:224-228, 1972). Virus infectivity was evaluated by both hemagglu- -
tination techniques and cytopathogenic effects, with identical results for -~ ~
each method. In Table 4 below the virus-inhibiting effects of two low drug ~ -
concentrations, 3 and 10 Jvg/ml, are depicted. Results are given as the log
decrease in infectivity of the virus inoculum. A log decrease of 4.0 is the ~ -
maximum obtainable, representing complete suppression of virus growth in our ; -
system. The virus inoculum of day 0 was always 100 times that amount required -
to kill 50 % of the tissue~culture cèlls (loo ICD50). These results indicate
that different derivatives suppress viral growth by from 3 to 10,000 fold, -
the most potent effect being exerted by 3-0-3'-(N',N'-dimethylamino-n-propyl)-
~lucose.
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TABLE 4
' ' ': '
Log Decrease -~
in Infectivity of
Virus Inoculum at
Compound _ _ _ _ _C n e tration of
3 ~g/ml 10~vg/ml
3-0-3'-(NI,Nt-dimethylamino-n-
propyl)-D-glucose 3.2 4.0 (max)
3-0~4'-(N-methylpiperidyl)-D- ~ ;
glucose 2.5 3.5
3-0-2'-(N~,N'-dimethylaminoethyl)- ~ - -
D-glucose 2.5 3.5
3-0-3~-(2',N',N'-trimethylamino-
n-propyl)-D-glucose 2.4 3.0 ! ;
~-N,N-dimethylaminoisopropyl ~-
glucoside 1.5 2.5
6-0-3l-(Nl~N~-dimethylamino-n-
propyl)-D-galactose 1.0 2.0
3-0-2i-(N~,NI-dimethylaminopropyl)~
D-glucose 1.0 2.0
3-0-2i-(N',NI-diethylami~oethyl)- `~i
D~glucose 0.5 1.0
6-0-2'-(N',N~-dimethylaminopropyl)~ ;~
D-galactose 0.1 0.5
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