Note: Descriptions are shown in the official language in which they were submitted.
11~3*~91
The present invention relates to a method for producing
cephem compound. More particularly, the present invention relates
to a new and unobvious process for preparing cephem compounds of
the formula (I):
S ~
2 ~ 1 o
N ~ CH2OCNH2 (I)
COOR
wherein R is hydrogen or an ester residue, and salts thereof.
The above compounds, particularly 7-amino-3-carbamoyl-
oxymethyl-3-cephem-4-carboxylic acid (i.e. the compound (I) wherein
R2 is hydrogen; hereinafter sometimes referred to briefly as 7-
ACC) are important intermediates for the production of cephalospor-
in antibiotics having a carbamoyloxymethyl group in the 3-position. `
7-ACC is a known compound and various processes for preparing it
have been reported. For example, published Japanese Patent
Application No. 32829/1973 teaches a method for producing 7-ACC
using 7-aminocephalosporanic acid (hereinafter referred to briefly
as 7-ACA) as the starting material. This method, however, is not
commercially advantageous in that it involves a large number of
steps, employs a costly starting material (7-ACA) and involves a
step of esterase hydrolysis.
A possible starting material for producing 7-ACC
appeared to be 7-(D-5-amino-5-carboxyvaleramido)-3-hydroxymethyl-
3-cephem-4-carboxylic acid (deacetyl-cephalosporin C; hereinafter
sometimes referred to briefly as DCPC), which is produced directly
by fermentation in high yield and at low-production cost, (Nature
New Biology) 246, 154 (1973), published Japanese Patent Application
No. 491/1974). But this route is still not satisfactory. Thus,
in this method, the 3-hydroxymethyl group is firstccnverted to a
carbamoyloxymethyl group and the 7-acylamide group must then be
cleaved to obtain 7-ACC. However, in the latter reaction, the
carbamoyl group reacts with the phosphorus pentachloride used as
. '~': - 1 - ~ '
iiQ;~
cleavage agent, as shown below, making it impossible to achieve
satisfactory results (Tetrahedron Letters 1976, 2401):
- la -
-
a~S
OCH
1 3 S~
RCONH t ~ 0
" PC15/Py ~ / \ O
,I N ~ - CH20CNH > ~ ¦ l
/ 1 2 ~_ N ~ - CH20CNHPC14
COOcH~2 l
COOCH~2 '
~ ~ Methanol
C ~ 2~ - N ~ CH20H ~ CH20CNHP(OC1~2
COOCH~
2 COOCH~2 _ COOCH~2
~RCO=acyl; ~-phenyl; and Py=pyridine~
It has now been discovered, by means of N.M.R. spectrometry that
the carbamoyl group in the 3-position of the cephalosporin nucleus is readily
silylated and that the silylated carbamoyl group resis~s attack by the halo-
genating agent e.g. phosphorus pentachloride.
Accordingly, the present invention provides a process for produc-
ing a cephem compound of the formula:
H2N~ ~
0 N ~ CH20CNH2 (I)
COOR
wherein R is hydrogen or an ester residue, or a salt thereofJ which com-
prises silylating a compound of the formula:
RlCONH~ o
N ~ CH20CNH2 (II)
COOR
wherein RlCO is an acyl group and R2 has the same meaning as defined above,
or a salt thereof to produce a compound silylated at the carbamoyl group of
the 3-position, halogenating the silylated compound to produce the correspond-
ing iminohalide, reacting the iminohalide with a lower aliphatic alcohol ~o
- 2 -
- . : . -
9~
produce the corresponding iminoether compound and subjecting the iminoether
compound to solvolysis.
ReferringJ now, to the above general formulae~ the acyl group
RlCO may be any of the acyl groups thus far known in the art of penicillins
and cephalosporins. Preferred, for example, are 5-amino-5-carboxyvaleryl,
phenylacetyl, phenoxyacetyl, etc. The most desirable are acyl groups of the
formula:
HooccH(cH2)3co-
(wherein R3 is a protected amino group).
In the above formulae, the protecting group of the protected
amino R3 may be any of the protective groups ~ se known in the art of
cephalosporins, for example, phthaloyl, naphthoyl, benzoyl, benzoyl -
substituted by nitro, halogen or lower alkyl (Cl 4) (e.g. chlorobenzoyl,
p-nitrobenzoyl, toluoyl, p tert-benzoyl, etcO), benzenesulfonyl, benzene-
-~ sulfonyl substituted by lower alkyl (Cl 4) (e.g. p-tert-butylbenzenesulfonyl,
ph~h~ ~y_
toluenesulfonyl, etc.), aryl-substituted acyl (e.g. phenylacetyl, ~h~n~
acetyl, etc.), camphorsulfonyl, alkyl-substituted sulfonyl (e.g. methane-
sulfonyl, etc.), aliphatic or halo-aliphatic carboxylic acid-derived acyl
groups (e.g. acetyl, valeryl, capryl, n-decanoyl, acryloyl, pivaloyl, chloro-
acetyl~ etc.), esterified carboxyl (e.gO tert-butoxycarbonyl, ethoxycarbonyl,
isobornyloxycarbonyl, phen~loxycarbonyl, trichloroethoxycarbonyl, benzyloxy-
carbonyl, ~methylsulfon~lethoxycarbonyl, ~-methylsulfonylethoxycarbonyl,
etc.~, carbamoyl groups ~e.g. methylcarbamoyl, phenylcarbamoyl, naphthyl-
carbamoyl, etc.), the corresponding thiocarbamoyl groups and so forth.
The group R2 is hydrogen or an ester residue. The ester residue
may in particular be one that is conventionally employed in the cephalosporin -
art. Thus, R2 may for example be benzhydryl, tert-butyl, 2,2,2-trichloro-
ethyl, p-nitrobenzyl, cyanomethyl, methylthiomethyl, methoxymethyl, pivaloyl-
oxymethyl or the like. In view of its ready availability, it is particularly
desirable to employ the compound wherein R2 is hydrogen.
_ 3 _
9~
The compound of general formula (I) forms salts with respect to
its amino or carboxyl functions. Thus, it forms salts with inorganic acids
such as hydrochloric acid, sulfuric acid, nitric acid, etc.; salts with
organic acids such as p-toluenesulfonic acid, oxalic acid, etc.; salts with
alkali metals or alkaline earth metals such as sodium, potassium, calcium,
magnesium, etcO, salts with organic bases such as triethylamine, trimethyl-
amine, triethanolamine, etc.
The compound (II) or salt thereof employed as starting material
in the process of the present invention is prepared by carbamoylating a
corresponding compound of formula (III):
RlcoNH / ~
N ~ --CH2OH (III)
COOR
or salt thereof.
This reaction may be conducted by the known procedures, for
example by the method described in published Japanese Patent ApplicationsNoO
16494/1972, NoO 81887/1973, No. 67222/1973, No. 67290/1973, No. 32829/1973
and No. 52083/1975. Thus, to effect the carbamoylation, normally a compound
of general formula ~III) is reacted with an isocyanate of general formula (IV):
R5NCo (IV)
- Cwherein R5 is a group substitutable by hydrogen)
to produce a compound of formula (V):
R CONH -rl~ S ~
~N~ L CH20CoNHR5 (V)
COOR
~wherein RlCO, R2 and R5 are as hereinbefore defined) and then, R5 in this
compound (V) is substituted by a hydrogen atom to obtain a compound of general
formula (II). The selection of a compound of general formula (V) and of
reaction conditions may be made in accordance with the teachings of the afore-
2791
mentioned prior patent literature references. Among the isocyanates ~R5NCo)mentioned in the above patent literature, compounds in which R5 is chloro-
sulfonyl, monohalogenoacetyl, dihalogenoacetyl or trihalogenoacetyl are
preferred. As compound (IV), chlorosulfonyl isocyanate is particularly de-
sirable, Thus, this compound may be reacted with a compound of general
formula (III) to obtain the corresponding compound of formula ~V). Then, by
contacting it with water under acidic conditions, ~V) can be easily converted
to a compound of general formula (II).
A large number of compounds of general formula ~III) are known
compounds. Any new compounds of formula ~III) may also be easily produced by
procedures analogous to these employed for making the known compounds.
The resultant compound of general formula ~II) is then silylated.
A suitable silylating agent is a compound of the formula: plp P3Si Hal,
wherein each of pl, p2 and P3 is a hydrocarbon residue such as a lower alkyl
of 1 to 4 carbon atoms (e.gO methyl, ethyl, n-propyl, i-propyl, n-butyl, etc.),
an aryl group Ce.g. phenyl, tolyl, etc.) or the like, and Hal is halogen,
preferabl~ chlorine or bromine, and one or two of pl, p2 and P3 may be halo-
gen, pre~erably chlorine or bromine, and one of pl, p2 and P3 may be hydrogen.
Furthermore, hexa-alkyl(Cl-C4) cyclotrisilazane, octaalkyl ~Cl-C4)cyclotetra-
silazane, trialkylCCl-C4)silylacetamide, bis-tri-alkyl~Cl-C4)silylacetamide
may be used as the silylating agent in the method of the present invention.
The preferred silylating agents are alkyl~Cl-C4)trihalogenosilane ~e.g.
trimethylsilylchloride), di-alkyl~Cl-C4)dihalogenosilane (e.g. dimethyl-
dichlorosilane~, di-alkoxy~Cl-C4)dihalogenosilane ~e.g. dimethoxydichloro-
silane, diethoxydichlorosilane), etc. This reaction is preferably conducted
in the presence of a base ~e.g. triethylamine, pyridine, picoline, N,N-
dimethylaniline, etc.). While the reaction proceeds in the absence of a
solvent, it is preferably conducted in an inert solvent such as dichloromethane,
dichloroethaneJ chloroform, benzene, toluene, tetrahydrofuran, etc. With res-
pect to 1 mol of compound ~II), the silylating agent is employed normally in
2~9~
excess, preferably in an amount of 1.2 to 2 times mols relative to
the theoretical amount. The base is desirably used in a proportion
of about 1 to 5 mols per compound (II). The reaction temperature
is normally about -20C to -40C and the reaction normally goes to
completion within about one hour. After the reaction has been com-
pleted, the reaction mixture either as it is or after having been
concentrated to a suitable concentration is subjected to the next
reaction. By this silylation reaction, a silyl group is intro-
duced into the carbamoyl group. Where the acyl group (RlCO) has
a free carboxyl group and where R2 in COOR2 is hydrogen, silyl
groups are also introduced into those carboxyl groups, producing
silyl esters. It is disclosed in published Japanese Patent
Application No. 40899/1970 that a silyl ester is an excellent
protective group for carboxy group when removing an acyl group.
The silylated compound thus obtained is then subjected
to cleavage of the amide linkage. The various techniques es-
tablished in the art of cephalosporins for such amide-cleavage
reactions may be utilized for this purpose. For example, the
procedures taught by Japanese Patent Publication No. 13862/1966
and published Japanese Patent Applications No. 95292/1975 and No.
96591/1975 may be followed, for instance. The procedure according
to the present invention comprises converting the silylated com-
pound to an iminohalide and, then, the latter to an iminoether
compound and, finally, subjecting the latter to solvolysis to
obtain the compound of general formula (I).
Thus, in the first place, the silylated compound is
halogenated, for instance with a halogenating agent such as
phosphorus pentachloride, to produce the iminohalide. With
respect to each mol of silylated compound, about 1 to 4 mols of
phosphorus pentachloride is normally employed. The reaction
temperature is usually about ~50 to about 45C. The reaction may
, - 6 -
ll~Z791
be conducted in an inert solvent such as dichloromethane,
chloroform, tetrahydrofuran, benzene or toluene. Following
this reaction for the production of said iminohalide,
the reaction mixture is normally contacted with a lower
aliphatic alcohol to convert the iminohalide to the
iminoether compound, ~he alcohol may for example be
methanol, ethanol, n-butanol or the like. ~his reaction
is normally carried out in an inert solvent such as
dichloromethane, chloroform, tetrahydrofuran or the like
aDd at a temperature in the range of about -50C and
+45C, ~he reaction normally goes to completion within
about 10 minutes to one hour. ~he resultant iminoether
compound is subjected to solvolysis, ~he solvolysis is
usually carried out by contacting the iminoether compound
with an alcohol, e,g. said lower aliphatic alcohol
solvent, or water or the lower aliphalic alcohol and ~ater.
~he amide linkage is cleaved by the solvolysis,
~he silyl group or groups are also removed by the action
of the lower aliphatic alcohol or water, ~hus, the compound
(I~ or its salt is produced in excellent yield in accordance
with the present invention, This solvolysis is normally
conducted under acid conditions, The solvent is used in
excess, ~he reaction temperature may be within the range
of about -50C to about 45C, the reaction being completed
in about 10 minutes to 1 hour, The acid condition may be
attained by the presence of an inorganic acid such as
hydrochloric acid, sulfuric acid, phosphoric acid, etc,
in the reaction mixture. ~he pH value of the mixture is
11~*791
usually not higher ~han 1.
The amide-cleavage reaction may also be accomplished
by reacting said iminohalide with hydrogen sulfide or
thioacetamide to obtain the thioamide derivative, then
activating this thioamide and subjecting this activated
compound to solvolysis (e.g. the specification of published
Japanese Patent Application No. 96591/1975). ~he conditions
of reaction (reaction temperature, solvent, etc.) between
the iminohalide and hydrogen sulfide or thioacetamide may
be similar to the conditions used for the aforesaid
reactions for the production of iminohalide and iminoether
compounds. The thioamide compound may be acti~ated, for
example by reacting it with trichloromethanesulfenyl
chloride or sulfur monochloride. The solvolysis of the thus
activated compound is effected by exactly the same procedure
as the solvolysis of said iminoether compound and gives
rise to the compound of formula (I).
Where ~2 in the resultant compound of formula (I)
is an ester residue, the compound in which R2 is hydrogen
may be produced if desired, by removing the ester residue
in a routine manner, e g. by hydrolysis, acid decomposition,
reduction or the like in accordance with the per se known
procedures
~ he solution containing compound (I) may be directly
subjected to the next reaction, or compound ~I) may be
isolated beforehand. ~he isolation of compound ~I) may
be conducted in a routine manner. ~or example, when the
reaction mixture is allowed to cool in the neighborhood
,
. . - , ,
.: ~ - . . . . .
,, . . ~ -
1~791
of its isoelectric point, 7-ACC separates out from the
mixture, ~his precipitate is recovered by filtration,
washed with an organic solvent and water and dried. If
desired, the compound may be further purified by a procedure
well known per se,
A good embodiment of the present invention may be
shown by the following reaction scheme,
HooccH(cH2)3coNH
R' O F~ cH2ocoNH2
COOH
~ silylating agent
Y OOCCH(CH2)3CONH F S~ 2
R3N ~ CH20Y
COOY
Xl ~ halogenating agent
Y OOCICH(CH2)3C=N F S~ 2
R3 N ~ CH20Y
cooyl
an aliphatic alcohol
(ROH)
OR
YlOOCpH(C~2 )3b'-N ~ 1'$~
R3 ~ N ~ CH20Y2
COOY
I the aliphatic alcohol
~ or/and water (solvolysis)
H2N I ~ S~ o
N ~ CH20CNH2 (7-ACC)
COOH
,
~Z791
In the above schcme, R3 is a protected amino; yl is
a silyl group; y2 is a silylated carbamoyl group; Xl is
halogen; and ROH is an aliphatic alcohol.
~ he end-products of the present invention are useful
as the starting materials for the production of various
cephem compounds having excellent antibacterial properties.
Particularly~ 7-ACC and its salts are of value as the
starting materials for the production of antibiotics
having the formula ~VI)
H2-n
HnN CCONH ~ ~S
N ~ CH20CONH2 ~VI~
oR4 0 COOR2
, wherein n is a number of a range O' n '1, and R4 is hydrogen
or a lower alkyl, and phamaceutically acceptable salts
thereof, ~he compounds of the formula ~VI) may form
pharmaceutical acceptable salts with respect to the
carboxyl function or with respect to the group represented
by the formula:
H2-n
HnN
, and the pharmaceutical acceptable salts may be salts
with the acids or bases above-mentioned regardin~ the
compound ~
~ he compound of formula ~VI~ in which R2 is hydrogen
and R4 is hydrogen may be produced, for example by the
following reaction steps.
-- 10 --
.. . . . - .
- - ~
. . . ~ ,., . , . :. :
~l~Z79~
7-ACC or its salt
XCH2COCH2COX ~ CH2 r 2
0--~
XCH2COCH2CONH ~ S~ o
O ~ CH20CNH2 (VII)
I COOH
I Nitrosating Agent
XCH2COCCONH 1~ S~
N ~ N ~ CH20CN~2 ~VIII)
OH COOH
,l H2NCSNH2
H2 nN ~ S
HnN ~ CCO~H ~ S~
N N ~ -CH OCONH (IX)
~whereln n has the meaning defined hereinbefore; X is
chlorine or bromine)
In the step of producing a compound (VII~ from 7-ACC,
the latter is acylated with 1 to 1 5 molar equivalents of
a 4-halogeno-3-oxobutyryl halogenide to give (VII). This
acylation re~ction is conducted in a solvent, such as
dimethylformamide, dlchloromethane, dimethylacetamide,
dimethylsulfoxide, chloroform, acetonitrile or the like,
or a mixture of such solvents, and in the presence of
1 to 3 molar equivalents of an organic base such as
triethylamine7 N,N-dimethylaniline, pyridine or the like.
~his reaction is conductad at a temperature between -40C
,
~l~Z~l
and 40C, preferably lmder cooiing at a temperature from
_~ to oC. ~he compound LVIl~ obtain?d is isola~ed as crystals
by extraction and concentration, etcO
The compound ~VII) is then nitrosated to (VIII).
~pecifically, compound ~VII) is p~viously dissolved in
a solvent, e.g. acetic acid or aqueous acetic acid, and
1 to 2 molar equivalents of a nitrosating agent such as
sodium nitrite is added The reaction is conducted at
-40C to ~20C. ~he resultant (VIII) is isolated as
powders by extraction and phasic transfer operations.
~ hen, (VIII) is reacted with 1 to 2 molar equivalents
of thiourea to produce (IX). ~his reac-tion is conducted
at O to 20C in a solvent, e.g. dimethylformamide,
dimethylacetamide, dimethylsulfoxide, ace-tonitrile or the
like, or a mixture o~ solvents ~he resultant ~IX) is
isolated and purified by such procedures as extraction,
phasic transfer, pH adjustment, crystallization, column
chromatography, etc.
Among compounds of formula ~VI), a compound ~X),
i.e. the compound ~VI~ wherein ~2 is hydrogen and R4 is a
lower alkyl group such as methyl, ethyl, n-propyl or i-
propyl:
H2_nN ~
HnN CCO~-H I ~S~ o ~X)
o~N~ CH20C~TH2
OY COOH
(wherein Y is the lower alkyl mentioned above~ n has the
meaning defined hereinbefore)
- 12 -
.. . .
'. . : ' , : . : ~
, .
- . . ', ~ ' : . -
- \
11~2 791
may be produced by reacting a carboxylic acid of formula
~XI~:
(XI)
N
OY
~wherein Y and n are as defined hereinbefore 9 Z iS hydrogen
or a protective group)
or a reactive derivative thereof with 7-~C. In the above
compound (XI~, the protective group Z is exemplified by
aromatic acyl groups such as benzoyl, benzoyl substituted
by halogen, nitro or lower alkyl (Cl 4) (e.g. chlorobenzoyl,
p-nitrobenzoyl, p-tert-butylbenzoyl, toluoyl, etc.),
naphthoyl, phenylacetyl, phenoxyacetyl, benzenesulfonyl,
benzenesulfonyl substituted by lower alkyl (Cl_4) (e.g. p-
tert-butylbenzenesul~onyl, toluenesulfonyl, etc ),
camphorsulfonyl, methanesulfonyl, aliphatic or halo-
aliphatic carboxylic acid-derived acyl groups (e.g. acetyl,
valeryl, caprilyl, n-decanoyl, acryloyl, pivaloyl,
halogenoacetyl(e.g. monochloroacetyl, monobromoacetyl,
dichloroacetyl, trichloroacetyl, etc.), etc. ~7 esterified
carboxyl groups (e.g. ethoxycarbonyl, tert-butyloxycarbonyl,
isobornyloxycarbonyl, phenyloxycarbonyl, trichloroethoxy-
carbonyl, benzyloxycarbonyl, etc.), carbamoyl groups (e.g.
methylcarbamoyl, phenylcarbamoyl, naphthylcarbamoyl, etc.)
and the corresponding thiocarbamoyl groups. The carboxylic
acid thus protected or unprotected may be used, either as
,,
.. . : . - . . .:
.
.
, . :
ll~Z7~
it is or as a reactive derivative thereof, as an acylating
agent for acylating the 7-amino group of compound (I).
~hus, the free acid ~XI), a salt thereof with an alkali
metal or alkaline earth metal ~e.g. sodium, potassium,
calcium, etc.) or with an organic amine (e.g. trimethyl-
amine, p~ridine, etc.) or a reactive derivative thereof,
such as the acid halide (e.g. acid chloride, acid bromide,
etc.), acid anhydride, mixed acid anhydride, active amide,
activated ester or the like may be employed for the
purpose of the above-mentioned acylation. As examples
of said activated ester may be mentioned the p-nitrophenyl
ester, 2~4-dinitrophenyl ester, pentachlorophenyl ester,
N-hydroxysuccinimide ester and N-hydroxyphthalimide ester.
~he mixed acid anhydride is exemplified by mixed anhydrides
with carbonic acid monoesters (e.g. monome-thyl carbonate,
monoisobutyl carbonate, etc.) and mixed anhydrides with
lower alkanoic acids which may optionally be substituted
by halogen (e.g. pivalic acid~ trichloroacetic acid, etc.).
Where the protected or unprotected carboxylic acid ~XI~
is employed as it is or in the form of a salt, a suitable
condensing agent is employed As examples of th6 condensing
agent may be mentioned N,N'-di-substituted carbodiimides
such as N,N'-dicyclohexylcarbodiimide, etc.; azolides
such &s N,N'-carbonylimidazole, N,N'-thionyldiimidazole,
etc.; dehydrating agents such as N-ethoxycarbonyl-2-
ethoxy-1,2-dihydroquinoline, phosphorus oxychloride,
alkoxyacetylene, etc.; 2-halogenopyridinium salts (e.g.
2-chloropyridinium methyl iodide, 2-fluoropyridinium
- 14
.. . : , :. . - . - -
-'' ~' "' '. , , ' ' . ~ ;
- -
- . , .
Z79~
methyl iodide, etc.) and so forth. Where such condensing
agents are employed, the reaction seems to proceed via
a reactive derivative of carboxylic acid ~XI). The
reaction is generally conducted in a suitable solvent
As examples of said solvent may be mentioned halogenated
hydrocarbons such as chloroform, methylene chloride, etc ;
ethers such as tetrahydrofuran, dioxane, etc ; dimethyl-
formamide, dimethylacetamide, acetone, water and mixtures
thereof. The proportion of carboxylic acid (XI) or a
reactive derivative thereof is normally about l to a few
molar e~uivalents per mol of compound ~I)o This reaction
is generally carried out at a temperature in the range of
-50 to ~40C. After the acylation reaction, the pro-tective
group may be removed. Removal of an amino-protecting group
may be accomplished by procedures known per se, for example,
the procedures described in Japanese Patent Application
Laid-open No 520~3/1975, ~ure and Applied Chemistry 7, ~35
(196~)) or by procedures analogous thereto. Where, for
example, the protective group Z is a monohalogenoacetyl
group (e.g. monochloroacetyl), removal of the monohalogeno-
acety] from the amino group may be accomplished by reacting
the acylated compound with its amino group thus protected
with thiourea and a basic reagent ~his reaction is normally
conducted in a solvent in the neighborhood of room temper-
ature and, in many instances, goes to completion in one
to ten and odd hours. The solvent may be any solvent
that will not interfere with the reaction. ~hus, for
example, ethers (e g. ethyl ether, tetrahydrofuran, dioxane,
ll~Z791
etc ), lower alcohols (e.g. methanol, ethanol, etc.),
halogenated hydrocarbons (e.g. chlorofor~, methylene
dichloride, etc ), esters (e.g. ethyl aceta-te, butyl~
acetate, etc.), ~etones (e,g. acetone, methyl ethyl ketone,
etc.), water and mixtures thereof may be mentioned.
~ eacting the protected compound ~X) with thiourea and
a basic reagent results in a selective and smooth progress
of the reaction for the desired removal of the monohalogeno-
acetyl group and~ hence, in the formation of compound ~X).
The basic reagent useful for this reaetion is exemplified
by the alkali metal or alkaline earth metal salts of lower
aliphatic carboxylic acids and inorganic or organie bases
with pKa values not less than 9 5, preferably pK values in
the range of 9 8 to 12 0. As examples of the salts of
lower aliphatic earboxylic aeids may be mentioned the salts
of lower aliphatie earboY.ylie aeid (Cl_6) ~e.g sodium
aeetate, potassium acetate, calcium acetate, barium aeetate,
sodium formate, sodium propionate, potassium hexanoate, ete.)
As examples of said inorganic bases may be mentioned the
alkali metal salts of carbonic acid (e,g. sodium carbonate,
potassium carbonate, ete,). As said organic bases, there
may be mentioned amines mono-, di- or tri-substituted by
lower alkyl (C1~4)(e.g. trimethylamine, triethylamine,
ethylamine, methylamine, diethylamine, dimethylamine, tri-
butylamine, dibutylamine, butylamine, ete.) and 5 to 6-
membered cyclic amines N-substituted by lower alkyl (~1-2)
(e.g, N-methylpyrrolidine, N-ethylpyrrolidine, N-methyl-
piperazine, N-ethylpiperazine, etc ) While, as aforesaid,
- 16 -
'
l~Z79~
thiourea is employed in this reaction, it is also possible
to employ ~- or N,N-substituted thiourea (e.g. methyl-
thiourea, N,N-diethylthiourea, N,N-hexamethylenethiourea,
etc.) in place of thiourea.
The starting material ~XI), e.g. 2-(2-aminothiazol-4-
yl)-2-methoxyiminoacetic acid (s~n-isomer) may ~e produced,
for example by the process described hereinafter in detail
First, a 4-halogeno-3-oxo-2-hydrox~iminobutyric acid
derivative of ~eneral formula ~XII):
(~ X2CH CoC-CooR7
.,
SN 4l (XII)
OR
~wherein x2 is halogen (e.g chlorine or bromine); R4 is
lower alkyl (e g. methyl~; R7 is lower alkyl (C1_3)(e.g.
ethyl))
is reacted with thiourea to obtain an 2-(2-aminothiazol-4-
yl)-2-methoxyiminoacetic acid derivative of general formu}a
(XIII):
H2-nN ~ 7
HnN C-COOR
(XIII~
SR4l
(wherein P4 and ~7 are as respectively defined above).
In this case, the compound ~XIII) is obtained as a mixture
of s~n- and anti-isomers. ~his reaction is normally
conducted by permitting thiourea to act upon compound (XII)
in an organic solvent such as ethanol, methanol, tetra-
hydrofuran or the like at room temperature or elevated
`\
27 91
temperature. The amount of thiourea may be about one to three
mols per mol of the compound (XII).
From the resultant mixture of said syn-and anti-forms
of compound (XIII), the desired syn-isomer may be separated
and recovered by the per se known procedure or by the procedure
disclosed in Canadian Patent Application No. 276,067 filed
April 13, 1977. The resultant compound (XI) wherein Z is hy-
drogen, if desired after the introduction of a protective group
Z by a procedure known per se, may be converted to a reactive
derivative thereof by a procedure which is also well known per se.
It is in order to mention that, in the above formulas,
the moieties of
H2 nN~L ZHl nN ~5
HnN HnN
are each supposed to assume a tautomeric structure of 2-amino-
thiazole and 2-iminothiazoline forms, thus:-
H2N ~ S HN ~ SN ~ ~ HN
~ ~ HN
(2-aminothiazole form) (2-iminothiazoline form)
The compounds (VI) and their pharmacologically
acceptable salts, may be administered as injections just as
the known cephalosporin and penicillin drugs. Thus,
- 18 -
., .
f
t
2791
these compounds are novel compounds having excellent
~ctivity against a broad spectrum of microorganisms
including Gram-negative bacteria such as scherichia coli~
Serratia marcescens, Proteus rettgeri, Enterobacter cloacae,
Citrobacter freundii etc, and are ~-lactamase-resistant
These compounds may be employed, for example, as disin-
fectants for removing said microorganisms from sursical
instruments or as a therapeutic agent for the management
of infectious diseases When a compound ~VI) or a salt
thereof is used as a therapeutic for the therapy of
infectio~s diseases, such as the intr-aperitoneal,
respiratory organ, urinary tract and other infections, it
may be safely administered by the parenteral route to
mammalian animals including man, mouse and rat at the
dose level of 1 to 20 mg daily per kilogram body weight, in
3 to 4 installments a day. ~he dosage forms may be conven-
tional Thus, for example, injectable preparations made by
se known procedures may be administered either intra-
muscularly or intravenously. ~he carrier to be employed in
such injectable preparations may for example be distilled
water or physiological saline.
Example 1
In dichloromethane (6 m~) is suspended benzhydryl 7-
phenylacetamido-3-carbamoyloxymethyl-3-cephem-4-carboxylate
(427 mg) Following the addition of pyridine (300 mg),
dimethyldichlorosilane (150 mg) is further added under
ice-cooling. The mixture is stirred at room temperature
for one hour, whereby the ester is completely dissolved.
-- 19 --
~l~Z791
~he solution is cooled to -20C and, after phosphorus
pentachloride (600 mg) is added, the mixture is stirred ~or
30 minutes. ~uring this period of time, the temperature
increases to -10C. The mixture is cooled to -40C and
methanol (4 m~) is added. It is then stirred for 15 minutes,
after which water (6 m~) and tetrahydrofuran (4 m~) are
added. ~he layers are separated and the water layer is
taken,while the organic layer is extracted with water The
water layers are combined, washed once with dichloromethane
and neutralized with sodium hydrogen carbonate It is then
extracted with a solvent mixture of dichloromethane-tetra-
hydrofuran and the extract is washed with aqueous sodium
chloride, dried, filtered and concentrated ~o the residue
is added petroleum ether, whereupon crystals separate out.
By the above procedure is obtained benzhydryl 7-amino-3-
carbamoyloxymethyl-3-cephem-4-carboxylate as crystals
melting at 120 to 12~C.
IR(KBr, cm l): 1775, 1728
NMR(d6-DMS0): ~ 3,53(2H, ABq, J=20Hz, 2-CH2), 4.66(2E,
ABq, J=13Hz, 3-CH2), 4 84(1H, d, J=5Hz, 6-H), 5 03
(lH d J=5Hz 7-H), 6.55(2H, broad-s. -OCNH2)~ 6 9
(lH, s, -CH~2), 7.39(10H, m)
Example 2
Dichloromethane (8.6 ~) is cooled to -30C in nitrogen
gas streams and 7-(D-5-p-t-butylbenzamido-5-carboxyvaleramido)-
3-hydroxymethyl~3-cephem-4-carboxylic acid di-triethylamine
salt (1.7 ~g) is added. ~he mixture is s-tirred and anhydrous
potassium carbonate (450 g) is then added and suspended.
- 20 -
ll~Z~9:1
At -25C, the coolin~ bath is removed. Then, dichloromethane
(lR) containin~; chlorosulfonyl isocyanate (450 g) is added
over a period of about 5 minutes and the mixture is stirred
at -10C for 40 minutes. The mixture is ad~usted to pH 0.1
to 0.2 by the addition of 3N-hydrochloric acid and stirred
at room temperature for 30 minutes. Then~ it is adjusted
to pH 2.7 with potassium carbonate and extracted with
tetrahydrofuran (12 ~). After the addition of triethylamine
(580 g), the extract is concentrated, dissolved in dichloro-
methane (15 ~) 7 dried over anhydrous magnesium sulfate,
filtered and concentrated to obtain a syrupy substance.
Upon addition of ether (5 ~), the syrup becomes powders.
The powders are recovered by filtration and dried. By the
above procedure is obtained 7-(r-C-p-t-butylbenzamido-5-
carboxyvaleramido)-3-carbamoyloxymethyl-3-cephem-4-carboxylic
acid di-triethylamine salt as crude powders (1.7 kg). While
this product includes the lactone, it is fully useful for
the next deacylation reaction. The above crude powders (3 g)
are taken, purified by column chromatography on ~mberlite XAD-2
and Sephadex LH-20, and lyophilized. The above procedure
gives a high purity grade of 7-(~-5-p-t-butylbenzamido-5-
carboxyvaleramido)-3-carbamoyloxymethyl -3-cephem-4-carboxyllc
acid di-triethylamine salt (1.12 ~;).
Il~(KBr, cm 1): 1770, 1330
N~(d6-rMS0): ~ 1.13 (18H, t, J=6Hz, Et3Nx2), 1 31~9H,
s,t-Bu), 1.4-2.0(4H, m- -CH(CH2)2-CH2-), 2.20(2H,
t,J=6Hz, -CH(CH2)2CH2-), 2.91(12H, q, J=6Hz, Et3Nx2),
3.17 ~ 3.48(2H, ABq, J=18Hz, 2-CH2), 4.24(1H, m~
* ~ra~
-- 21 --
- . : - . - . . .
. - ' ''. . . ' , . :
-,'. . ~
. -
. - ~
~91
-CF[(CH2)3-), 4.66 & 4.87(2H~ ABq, J=13Hz, 3-CH2),
4.94(1H, d, J=5Hz, 6-H), 5.50(1H, dd, J=5 & 8Hz, 7-H),
6.44(2H, broad-s, -OCONH2), 7.46(2H, d, J=8Hz, Arom-H),
7.79(2H, d, J=8Hz, Arom-H), 8.03(1H, d, J=8Hz, -CONH-),
8.64(1H, d, J=8Hz, -CO~I-)
~lemental analysis, for C381:I62N609~H2o
Calcd. C, 57.26; H, 8.09; N, 10~54
~ound C, 57 17, H, 8.41j N, 10.38
In nitrogen gas streams, 7-(D-5-p-t-butylbenzamido-
5-carboxyvaleramido)-3-carbamoyloxymethyl-3-cephem~-
carboxylic acid di-triethylamine salt (1.7 kg) is dissolved
in dichloromethane (7.3 R) and, then, N,~-dimethylaniline
(2.6 ~) and dimeth~ldichlorosilane (970 mR) are added. The
mixture is stirred at 20 to 30C for 40 minutes. Then, after
cooling to -35C, phosphorus pentachloride (1.25 kg) is
added in a single dose and the mixture is stirred at -20C
for 15 minutes. ~hen, methanol (5.0 ~) is added dropwise
at -30 to -25C, after which it is stirred at -20C for 20
minutes Followin~ the addition of water (4.0 R), the
mixture is further stirred at 10 to 13C for 30 minutes.
~he mixture is adjusted to pH 3.5 with 20 O/G sodium carbonate
and the resultant precipitate is recovered by filtration
and washed with dichloromethane (5 ~) and methanol (5 R).
By the above procedure is obtained 7-amino-3-carbamoyloxy-
methyl-3-cephem-4-carboxylic acid as crude powders (600 g).
The powders are added to 4N-hydrochloric acid (2 R) and
after 15 minutes' stirring at room temperature, the
insolubles are filtered off. To the filtrate is added
22
, ' ,: ' . ': '
l~Z791
ethyl acetate (~00 m~) and the mixture is adjusted to pH 3 5
with 20 ~ sodium carbonate. After the addition of methanol
(2 ~), the mixture is stirred under ice-cooling for 30
minutesG The resultant cxystals are collected by filtration,
washed 3 times with water (300 m~) and 3 times ~ith acetone
(400 m~). B~ this procedure is obtained 7-amino-3-carbamoy-
oxymethyl-3-cephem-4-carboxylic acid (175 g) of high purity.
UV~max (pH 6.5, phosphate) 265 nm( s7885)
I~(KBr, cm 1): 1800, 1710, 1333
NM~(d6-D~MS0): ~ 3,34 & 3.57(2H, ABq, J=18Hz, 2-CH2), 4.58
& 4.87(2H, ABg, J=13Hz, 3-CH2), 4.76(1H, d, J=5Hz,
6-H), 4.96(1H, d1 J=5Hz, 7-H), 6 50(2H, broad-s,
-OCONH2)
Elemental analysis, for C9H11~305S-0 5H20
Calcd. C, 38.29; H, 4 29; ~, 14.89
~ound C, 38.~4; H, 4.25; ~, 14.12
Example 3
7-(D-5-phthalimido-5-carbox~valeramido)-3-hydroxymethyl-
3-cephem-4-carboxylic acid (5.21 ~) is dissolved in a mixture
(1:1 volume/volume) of tetrahydrofuran and dichloromethane,
and the solution is cooled to -35C. ~hen, under stirring,
a mixture of chlorosulfonyl isocyanate (2 m~) and dichloro-
methane (2 m~) is added over a period of 10 minutes.
During this period of time, the temperature is held at
-35to -30C. ~he temperature is then increased to 13C and,
following the addition of 3N-hydrochloric acid (10 m~), the
mixture is stirxed for 20 minutes. A saturated aqueous
solution of sodium chloride (30 m~) is added and the organic
" ~ - ~ ' " . ' ': :
1~2791
layer is separated. ~o this organic layer is added a
saturated aqueous solution of sodium chloride (10 m~) and
water (10 m~) and, with stirring, the mixture is adjusted
to pH 4 0 by t~e addition OI aqueous sodium carbonate.
~he water layer is separated and washed with a mixture of
tetrahyclrofuran (20 m~) and dichloromethane (20 m~ he
mixture (50 m~) of tetrahydrofuran and dichloromethane
(1:1 volume/volume) is freshly added and under stirring,
hydrochloric acid is added to bring the pH to 2~5. The
organic layer is separated, washed with a saturated aqueous
solution of sodium chloride, dried over anhydrous mag~esium
sulfate and concentrated under reduced pressure. The
concentration residue is dissolved in tetrah~rdrofuran (20 mk),
and ethyl acetate (100 m~) is added. ~he mixture is
concentrated to about 60 m~ and the precipitate is filtered
off. To the filtrate is added ether (200 m~) and the
precipitate is recovered by Iiltration, washed with ether
and dried over phosphorus pentoxide. By the above procedure
is obtained 7-(D-5-phthalimido-5-carboxyvaleramido)-3-
carbamoyloxymethyl-3-cephem-4-carboxylic acid (4.6 g).
IR(KBr, cm 1): 1789, 1330
~MR(d6-~MS0) o 1.26-2.36(6H, m, -(CH2)3-), 3.45(2~1, ABq,
J=18Hz, 2-CH2), 4.74(1H, t, J=7Hz, -CH-), 4.77(2H,
ABq, J=13Hz, 3-CH2), 5.06(1H, d, J=5Hz, 6-H), 5.62
(lH, dd, J=5 & 8Hz, 7-H), 6.56(2H, s, CO~H2), 7 92
(4H, s, arom-H), 8.74(1H, d, J=8Hz, -CO~H--)
7-(I)-5-phthalimido-5-carboxyvaleramido)-3-carbamoyl-
oxymethyl-3-cephem-4-carboxylic acid (4,6 g) is dissolved
-- 24 --
in a mixture of dichloromethane (30 m~), triethylamine
(1.8 m~) and l~,N-dimethylaniline (6.~ m~). Then, dimethyl-
dichlorosilane (3 0 m~) is added and the mixture is stirred
at room temperature for one hour, after which it is cooled
to -3~C and phosphorus pentachloride (2.75 g) is added.
~he mixture is stirred at -30 to -2~C for 15 minutes,
after which time it is cooled to -40C and methanol (15 m~)
is gradually added. During this time, the temperature of
the solution is maintained between -30 and -20 ~.
~ hen, the mixture is stirred at -20 to -17C for 20
minutes, at the end of which time water (15 m~) is added
~he mixture is adjusted to pH 3.7 by the addition of aqueous
sodium car~onate and stirred under ice-cooling for one hour.
~he resultant precipitate is recovered b~ filtration,
washed with dichloromethane, methanol and water in the
order mentioned and dried over phosphorus pentoxide. By
the above procedure is obtained 7-amino-3-carbamoyloxy~ethyl-
3-cephem-4-carboxylic acid (1.70 g) In IR spectrum this
product agrees with the product obtained in Example 2.
Example 4
In water (19 m~) is dissolved deacetyl-cephalosporin
C sodium monohydrate (7.0 g), followed by addition of tetra-
hydrofuran (9 m~) and N-carboethoxyphthalimide (6.8 g).
Under stirring, an aqueous solution of potassium carbonate
is added so as to maintain the p~ value of the mixture at
9.1 to 9.3 for 30 minutes and at 9.7 to 9 8 for a succeeding
one hour. Thereafter, tetrahydrofuran (26 m~) and dichloro-
methane (32 m~) are added and under ice-cooling and stirring,
~ 25
11~Z79~
3N-hydrochloric acid is added to bring the pH to 2.5. The
organic layer is separated. The water layer is extracted
with a mixture of tetrahydrofuran (18 m~) and dichloro-
methane (18 m~) and the organic layers are combined, washed
with aqueous sodium chloride and dried over anhydrous
magnesium sulfate ~he solvent is then distilled off,
whereby a syrupy product is obtained as the residue. This
residue is dissolved in tetrahydrofuran (25 ~) and dichloro
methane (25 m~) is added. The mixture is cooled to -35C
and, under stirring, a mixture of chlorosulfonyl isocyanate
(2 m~) and dichloromethane (2 m~) is added over a period
of 10 minutes During this time, the temperature of the solution
is maintained at -35 to -30C. The temperature is increased
to 13C over a period of 30 minutes and, after the addition
of 3N-hydrochloric acid (10 m~), the mixture is stirred for
30 minutes ~ollowing the addition of aqueous sodium
chloride (30 m~), the organic layer is separated, washed
with aqueous sodium chloride and dried over anhydrous
magnesium sulfate. Following the addition of triethylamine
(6.3 m~), the solvent is distilled off to recover a syrupy
residue. This residue is dissolved in dichloromethane
(50 m~), followed by the addition of N,N-dimethylaniline
(13 m~) and, then, of dimethyldichlorosilane (6 m~). The
mixture is stirred at room temperature for one hour Then,
the mixture is cooled to -40C and, under stirring,
phosphorus pentachloride (5.5 g) is added. The mixture is
held at -30 to -25C for 15 minutes and, then, cooled to
-40C. Methanol (30 m~) is gradually added at this temperature
- 26 -
7gl
~uring this time, the temperature of the solution is maintained at
-30 to -17C ~he temperature is then maintained at -17C
for 20 minutes, at the end of which time the mixture is
adjusted to pH 3 7 with aqueous sodium carbonate and stirred
under ice-cooling for one hour. The precipitate is recovered
by filtration, washed with dichloromethane, methanol, water
and acetone in the order mentioned and dried over phosphorus
pentoxide By the above procedure is obtained 7-amino-3-
carbamoyloxymethyl-3-cephem-4-carboxylic acid (2 32 g).
In IR spectrum, this product is found to agree with the
product obtained in Example 2.
Reference Example 1
In dichloromethane ~2 mR) is suspended benzhydryl
7-phenylacetamido-3-carbamoyloxymethyl-3-cephem-4-carboxylate
(139 mg) and, after the addition of pyridine (100 mg),
dimethyldichlorosilane (50 mg) is added under ice-cooling.
~he mixture is stirred for about 50 minutes to obtain a
homogeneous solution. An additional amount of pyridine
(50 mg) is added and the mixture is cooled to -20C,
and phosphorus pentachloride (200 mg) is added. Then,
under ice-cooling, the mixture is stirred for 30 minutes,
after which it is cooled to -10C and water (2 mR) and
tetrahydro~uran (2 mR) are added. The mixture is separated
into phases and the organic layer is taken and assayed by
thin layer chromatography ~he chromatogram shows only a
spot at the same Rf value as that of the starting compound
The above mixture is dried, concentrated and the residue
is treated with ether ~he resultant crystals are recovered
- :
ll~Z791
by filtration. ~he I~ spectrum of this product is in
complete agreement with that of benzhydryl 7-phenylacetamido-
3-carbamoyloxymethyl-3-cephem-4-carboxylate
The same reaction as above is carried out without the
use of dimethyldichlorosilane ~he thin layer chromatography
of this re~ction product mixture revealed no spot of the
starting compound, with the spot of no migration being
evidenced (developer solvent;ethyl acetate:dichloromethane=
8:2)
Reference Example ?
(1) Di~etene (189 g) is dissolved in dichloromethane
(~45 m~) and, under cooling at -50~, chlorine (159 g)
is introduced. Separately, 7-amino-3-carbamoyloxymethyl-
3-cephem-4-carboxylic acid (410 g) and triethylamine
(334 g) are dissolved in a mixture of dimethylformamide
(1.5 ~) and dichloromethane (1 5 ~) After the solution
is cooled to -25C, the above reaction mixture is added
dropwise at a temperature not exceeding -18C, at which
temperature the mixture is stirred for 30 minutes. ~hen~
phosphoric acid (1 kg), water (3 75 ~), methyl ethyl ketone
(8.5 ~) and ethyl acetate (3 ~) are added to the above
reaction mixture and, under stirring, sodium chloride is
added to saturation. The organic layer is taken and the water
layer is extracted with methyl ethyl ketone (4.2 ~) and ethyl
acetate (1.5 ~) The organic layers are combined, washed
3 times with a saturated aqueous solution of sodium chloride
(1 5 ~3 and dehydrated over anhydrous magnesium sulfate.
The solvent is then distilled off and ethyl acetate (500 m~)
- 2~ -
.
.. . .'
~ .
11~Z79i.
is added to the residue. The resultant crystals are
collected by filtration and dried By the above procedure
is obtained 7-(3-oxo-4-chlorobutyrylamino)-3-carbamoyloxy-
methyl-3-cephem-4-carboxylic acid (463 g).
IR(KBr, cm 1): 1773, 1745(sh.), 1720, 1660, 1540, 1~35
NMR(d6-~M~0): ~ 3.42 ~ ~.66(2H, ABq, J=18Hz, 2-CH2),
3.60(2H, s, ~COCH2CO-), 4.~6(2H, s, C~CH2), 4 64 ~
4.94(2H, ABq, J=13Hz, 3-CH2), 5.12(1~, d, J=5Hz, 6-H),
5.68(1H, dd, J=5 ~ 8Hz, 7-H), 6 52(2H, broad-s,
CONH2), 9 02(1H, d, J=8Hz, -CO~H-).
(2) In a mixture of acetic acid (2.8 ~) and water (0.7 ~)
is suspended 7-(3-oxo~-chlorobutyrylamino)-3-carbamoyloxy-
methyl-3-cephem Jl-carboxylic acid (463 g), and sodium
nitrite (81.5 g) is added over a period of about 10
minutes, the temperature being maintained at 0 to 3C
After the addition has been completed, the mixture is
stirred at the same temperature for 30 minutes, after which
time phosphoric acid (500 m~), ethyl acetate (15 ~) and
water (4.5 ~) are added. Then, sodium chloride is added
to saturation ~he organic Iayer is taken and the water
layer is extracted with ethyl acetate (5 ~ he organic
layers are combined, washed twice with a saturated aqueous
solution of sodium chloride (3.5 ~) and dried over anhydrous
magnesium sulfate ~he solvent is distilled off and
dichloromethane (500 m~) and petroleum ether (2 ~) are
added. ~he resultant precipitate is recovered by filtration
and dried. By this procedure is obtained 7-(2-hydroxyimino-
3-oxo-4~chlorobutyrylamino)-3-carbamoyloxymethyl-3-cephem-4-
- 29 -
- .,. - ~ .
. . , . ~ . -,
91
carboxylic acid (~n-isomer)(4~3 g)
IR(KBr, cm 1): 1785, 1730(sh), 1715, 1660, 1545, 1330
~MR(d6-rMS0): ~3 42 & 3A64(2H, ABq, J=18Hz, 2-CH2), 4 62 &
4 92(2H, ABq, J=13Hz, ~-CH2), 4 81~2H, s, C~CH2-),
5 15(1H, d, J=5Hz, 6-H), 5 78(1H, dd, J=5 & 8Hz, 7-H),
6 52(2H, broad-s, CONH2), 9 26(1H, d, J=8Hz, -CO~H-),
13 12(lH, s, =N-OH).
(Z) In dimethylacetamide(600 m~) is suspended 7-(2-
hydroxyimino-3-oxo-4-chlorobutrylamino)-3-carbamoyloxy-
methyl-3-cephem-4-carboxylic acid (~-isomer)(400 g)
together with thiourea (76.1 g) ~he suspension is stirred
at room temperature for 6 hours, at the end of which time
ether (3 ~) is added. After stirring, the supernatant is
discarded
Methanol (2 ~) is added to the residual mixture~.
The resultant mi~ture is added dropwi~e to ethyl ac~ta~e (24 1).
~he resultant precipitate is recovered by filtration,
dissolved in methanol (1 ~) and added dropwise to ethyl
acetate (20 ~) ~he precipitate is recovered by filtration
and dried This precipitate is dissolved in an aqueous
solution of sodium hydrogen carbonate (160 g) and chromato-
graphed on a column of Amberlite XAD-2. Development is
carried out with water and the active fractions are pooled,
concentrated and lyophilized. The lyophilizate is purified
by column chromatography on Sephadex ~H-20. ~he active
fractions are concentrated and lyophilized By the above
procedure is obtained sodium 7-~2-(2-imino~-thiazolin-4-
yl)-2-hydroxyiminoacetamido)-3-carbamoylo~ymethyl-3-cephem-
- 30 -
.
--
ll~Z79~
4-carboxylate (syn-isomer)(118.5g)
IR(KBr, cm 1): 17701 17107 1670, 1610, 1540, 1330
NM~(r20): ~ 3.39 & 3.70(2~, ABq, J=18Hz, 2-CH2), 4.70
4.92(2H, ABq, J=13~z, 3-CH2), 5.24(1~, d, J=5Hz,
6-H), 5.86(1H, d, J=5Hz, 7-H), 6 98(1H, s, thiazoline
5-H)
W ~ H20 nm (~): 225(19700), 258(15000)
max
Reference ~xample 3
(1) Ethyl 4-chloro-3-oxo-2-hydroxyiminoacetate (121 g)
and thiourea (47.6 g) are added to ethanol (600 m~) and
the mixture is stirred at room temperature for 3 hours.
~he ethanol is distilled off under reduced pressure, and
water (350 m~) is added to the residue. ~he water layer
is washed with ether, neutralized (pH 7.5) with sodium
hydrogen carbonate and extracted with a 1:1 (volume/volume)
mixture of ethyl acetate and tetrahydrofuran. The organic
layer is washed with water and dried. ~herea~ter, the
solvent is distilled off to obtain a crystalline product
(45 g).
This product is purified by chromatography on silica
gel (developer system=ethyl acetate-n-hexane) and the anti-
form of ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate
is obtained from a leading portion of the eluate while
the syn-form of the same compound is obtained from a
trailing portion of the eluate.
s~_-Isomer: White crystals with a tingle of pale yellow;
m~p.185.5C
- 31 -
, ~
. : . . , . . , ~ ~- .
ll~Z79~
Elemental analysis, for C7HgN303$
Calcd. C, 39.06; H, 4 21; N, 19 52
Found C, 39.28; H, 4.10; N, 19.63
z :7/~
~MR(d6-~MSO): ~ 6 80(1H, s, thi~ol 5-H~, 7.12(2H, broad,
s., NH2), 11.6(1H, s, OH)
(2) Sodium carbonate (10.6 g) is dissolved in water
(150 m~) and a solution of ethyl 2-(2-aminothiazol-4-yl)-2-
hydroxyiminoacetate (s~n-isomer)(10.7 g) in a mixture of
tetrahydrofuran (150 m~) and methanol (50 m~) is added.
Under ice-cooling~ dimethyl sulfate (12.6 g) is added
dropwise over a period of 5 minutes. After the dropwise
addition has been completed, the ice bath is removed and
the mixture is stirred at room temperature. In this stage,
a white crystalline substance begins to separate out.
After 3 hours, a major part of the organic solvent is
distilled off and the residue is cooled with ice. The
precipitate is recovered by filtration, rinsed with water
and dried.
By the above procedure is obtained ethyl 2-(2-amino-
thiazol-4-yl)-2-methoxyiminoacetate(syn-isomer) as white
crystals melting at 163 to 164CC.
~lemental analysis, for C8Hl1N303S
Calcd. C, 41.91j H, 4.84; N, 18.33
~ ound C, 41.57; H, 4.76; N, 18.07
~MR(crcQ3) ~: 4.0 ~ OCH3), 5 80(2H, broad s., ~H2),
6.74(1H, s, 5H)
(3) In N,N-dimethylformamide (10 m~) is dissolved ethyl
2-(2-aminothiazol-4-yl)-2-methoxyiminoacetabe~s;gn-isomer,
- 32 -
- , .................... ~ ., ' : ;'
' ' '' ''' ' ' , :
11~Z791
m.p. 163 to 164C) (2.15 g) and, under ice-cooling7 chloro-
acetyl chloride (1.27 g) is added dropwise. ~he mixture is
stirred under ice-cooling for 30 minutes and, then, at room
temperature for 30 minutes, at the end of which time water
(50 m~) is added. ~he mixture is extracted twice with
ethyl acetate (100 m~ each) The extracts are combined,
washed with 5 ~ aqueous sodium hydrogen carbonate and a
saturated aqueous solution of sodium chloride in the order
mentioned and dried. The solvent is distilled off, whereupon
ethyl 2-(2-chloroacetamidothiazol-4-yl)-2-methoxyimino-
acetate (syn-isomer) is obtained as crystals melting at
111 to 112C
Elemental analysis, for CloH12N304SC~
Calcd. C, 39.29~ H, 3.96; N, 13.74
~ ound C, 39.15) H, 3.91; N, 13.69
NMR(CDC~3): ~ 4.00( H, s~ =NOCH3), 4.24(2H, s, C~CH2CO),
C 7.15(lH, s, thi~ol 5-H)
(4) ~thyl 2-(2-chloroacetamidothiazol-/l-yl)-2-methoxy-
iminoacetate(s~n-isomer) (9.62 g) is dissolved in a solution
containing water (85 ml), ethanol (452 ml) and p~tassium
hydroxide (9 g). ~he mixture is stirred at
room temperature for 2 hours. ~he ethanol is distilled
off under reduced pressure and water (85 m~) is added to
the residue. The mixture is washed with ethyl acetate
(100 m~) and the water layer is adjusted to pH 2 with 10 /c
hydrochloric acid and extracted twice with 200 m~ portions
of ethyl acetate. ~he extracts are combined, washed with
a saturated aqueous solution of sodium chloride and dried.
-- 33 -
.
. .
7~1
The solvent is then distilled off, whereupon 2-(2-chloro-
acetamidothiazol-4-yl)-2-methoxyiminoacetic acid (syn-
isomer) is obtained as crys-tals melting at 170 to 171C.
Elemental analysis C8H8N804SC e
Calcd. C, 34 60; H, 2.90; ~, 15,13
~ lound C, 34.97; H, 3.03; ~, ~4.74
NMR~d6-DMSO). ~ 3.95(3H, s, =NOCH~), 4.40(2H, s, C~CH2CO),
7.57(1H, s, thiazole 5-H)
(5) In dry tetrahydrofuran (60 mR) is dissolved 2-(2-
chloroacetamidothiazol-4-yl)-2-methoxyiminoacetic acid
(s~n-isomer)(1.5 g) and, under stirring, triethylamine
(0 55 g) is added The mixture is cooled to -10C and
isobutyl chloroformate (0.74 g) is added dropwise The
mixture is stirred at that temperature for 2 hours. ~o
the resultant mixed acid anhydride solution is added a
solution (ice-cooled) of triethylamine (0.55 g) and 7-
amino-3-carbamoyloxymethyl-3-cephem-4-carboxylic acid
(].5 g) in 50 /c aqueous tetrahydrofuran (60 me). The
mixture is stirred under ice-cooling for one hour and,
then, at room temperature for 2 hours. After a major part
of the tetrahydrofuran is distilled off under reduced
pressure, water (600 me) and, then, ethyl acetate (120 m~)
are added. The mixture is adjusted to pH about 2 with 1~-
hydrochloric acid and separated into two phases The
water layer is extracted 3 times with ethyl acetate (150 me
each). ~he ethyl acetate layers are combined, washed with
water, dried and concentrated to recover 1.75 g of 7-~2-(2-
chloroacetamidothiazol~4-yl)-2-methoxyiminoacetamido)-~-
- 34 -
.. .
llGZ79~.
carbamoyloxymethyl-3-cephem-4-carboxylic acid.
The entire amount of this product is dissolved in
tetrahydrofuran (45 m~), and after the addition of thiourea
(0 6 g) and sodium acetate trihydrate (1 g), the mixture
is stirred at room temperature for 4 hours. ~he precipitate
is recovered by filtration, dissolved in water (30 m~) and
adjusted to pH about 7.0 with sodium hydrogen carbonate.
It is then purified by passage through a column of Amberlite
XAD~-2. By the above procedure is obtained sodium 7-(2-(2-
aminothiazol 4-yl)-2-methoxyiminoacetamido)-3-carbamoyloxy-
methyl-3-cephe~-4-carboxylate (syn-isomer) as white powders
100 mg.
NMR spectrum (D20): ~ 3.48(2H, q, 2-CH2), 3.92(3H, s, OCH3),
4.16(2H, q, 3-CH2); 5.27(1H d, 6-H), 5 70(1H, d,
7-H), 6.95(1H, s, thiazole ~
-
