Note: Descriptions are shown in the official language in which they were submitted.
~--`
1~64478
This invention relates to novel cephalosporin compounds
having novel acyl groups at the 7-position and preparations
thereof More particularly, this invention relates to 7-
methoxycephalospori~ compounds which have the formula:
NH2 ~S ~ R2 O,CM3
N CH2CO~H j ~S~
N ~ ~3 (I)
COOE
wherein ~2 stands for hydrogen or a halogen; ~3 stands
for methyl, acetoxymethyl, carbamoyloxymethyl, an alkoxy-
methyl, an alkylthiomethyl, 2-carboxy-1-ethenyl or a hetero-
cyclic thiomethyl group, or a pharmaceutically acceptable
salt thereof and also relates to processes for producing
the same.
Hereto~ore, studies on synthestic cephalosporin
compounds have been directed to the conversion of 7-amino-
cephalospora~ic acid to various acyl derivatives at the 7-
position or to derivatives at the 3-acetoxy group in order
to synthesize compounds having either a broad antibacterial
spectrum or a specific antibacterial spectrum. However,
these known cephalosporin derivatives are not yet satis-
factory in antimicrobial activities against a wide variety
of microorganisms. Hence, a compound has been sought after
which has a broad antimicrobial spectrum and is effective
even at a lower concentration
After a research we discovered that 7-methoxycephalos-
porin compounds of the above general formula (I) are not
only highly active against a broad spectrum of Gram-positive
-
:, . , : .
1064478
and Gram-negative bacteria but also eminently active against
antibiotic resistant strains and even those species of micro-
organisms against which the conventional cephalosporin
compounds are inactive. The invention is based on the above
finding.
Referring, now, to the above formula (I), ~2 means
hydrogen or a halogen such as chlorine and bromine, R3 stands
for methyl, acetoxymethyl, carbamoyloxymethyl, an alkoxy-
methyl such as methoxymethyl, an alkylthiomethyl such as
methylthiomethyl, 2-carboxy-1-ethenyl, or a heterocyclic-
thiomethyl group. ~he heterocyclic group contains not less
than one nitrogen which may be in the oxide form or, in
addition to nitrogen or nitrogens, such others as oxygen
or/and sulfur. ~he nitrogen-containing heterocyclic group
desirably has one to four hetero atoms in its heterocyclic
ring and the ring may be 5 or 6 membered one As such
heterocyclic group are exemplified pyridyl, N-oxido-pyridyl,
pyrimidyl, pyridazinyl, ~-oxido-pyridazinyl, pyrazolyl,
diazolyl, thiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl,
1,3,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,2,3-oxadiazolyl,
1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, 1,2,5-oxadiazolyl,
1,2,3-triazolyl, 1,2,4-triazolyl, lH-tetrazolyl, 2H-tetra-
zolyl and so on. And these heterocyclic groups may have
such common substituents as lower alkyl groups, e.g. methyl,
ethyl, trifluoromethyl, propyl,isopropyl, butyl, and
.,
-~ isobutyl, lower alkoxy groups, e.g. methoxy, ethoxy, propoxy,
isopropoxy, and butoxy, halogens, e.g. chlorine, and bromine,
and so on.
- 2 -
.,
.. : : . ::: .
:' . , ~ . ~ :' ' ' ', .
-
1064478
The 7-methoxycephalosporin compounds (I) may be used
with the 4-carboxyl function being left free or, if desired,
may be put to use as salts, for example the salts of non-
toxic cations, e.g sodium, potassium etc ; basic amino
acids~ e.g. arginine, ornithine, lysine, and histidine,;
polyhydroxyalkylamine; e g N-methylglucamine, diethanol-
amine, triethanolamine, tris-hydroxymethylaminomethane and
so on '~he aforesaid compounds may each be used also with
its 4-carboxyl group transformed into an ester, for example
as a biologically active ester derivative which, for instance,
is conducive to an increased blood level and a prolonged
action As the ester residues beneficial to this goal,
there may be mentioned a-alkoxy-a-substituted methyl
groups, e g alkoxylmethyl groups, a-alkoxyethyl ~roups
such as methoxymethyl, ethoxymethyl, isopropoxymethyl, a-
methoxyethyl, a-ethoxyethyl, etc ; alkylthiomethyl groups
such as methylthiomethyl, ethylthiomethyl,isopropylthio-
methyl, etc ; acyloxymethyl groups or a-acyloxy-a-substi-
tuted methyl groups such as pivaloyloxymethyl, a-acetoxy-
butyl, etc
~ he contemplated compound of this in~ention may take
two tautomeric forms as shown below by way of formulas but,
in this specification, the compound is shown in the thiazole
form, i.e. formula (I),
NH2 ~ S ~ R2 O,CH3 ~, ~ OCH3
N CH2CONH ~ ~ ~3 = HN CH2CO~H ~ ~ 3
(I) COOH (I COOH
,','.
. ~ .
- 3 -
- .
~ . : '.: ' ' ' ' . ' .' ' :
,
~064478
The 7-methoxycephalosporin compounds (I) of this
invention each have a broad antimicrobial spectrum, i.e.
activity against Gram-negative and Gram-positive bacteria,
and particularly display greater activity than the known
cephalosporins against antibiotic resistant strains of such
Gram-negative bacteria as ~scherichia coli, Serratia marcesens,
Proteus vulgaris, Pseudomonas aeruginosa and so on. ~here-
fore, these compounds are of use in the treatment of infec-
tions with the aforementioned bacteria in man and animals,
giving excellent therapeutic effects, Like the known cephalos-
porin dru~s, the contemplated compounds (I) of this invention
may each be administered to patients in such dosage forms
as in~ections, capsules, tablets, granules, etc. and, if
necessary, together with a physiologically acceptable vehicle
or excipient, as solutions, suspensions, solid preparations
and so on.
;- Specifically, sodium 7~-methoxy-7~-(2-aminothiazol-4-
ylacetamido)-3-(1-methyl-lH-tetrazol-5-ylthiomethyl)-3-
cephem-4-carboxylate, for instance, is administered intra-
muscularly at a daily dose level of about 5 to 20 milli-
grams per kilogram body weight in three to five divided
doses daily and this therapy is particularly effective in
the treatment of respiratory and urinary tract infections.
~ he 7-methoxycephalosporin compounds (I) can be pre-
pared by means of a method known for the production of
analogous compounds thereof. For example, by reacting a
7-methoxycephalosporin compound of the formula:
.
.- . - .
' ::, ., ~ . : . , ~
.
: . . . . . . . .
- 1064478
2 ,~ (]I)
. COOH
wherein the symbol has the meaning defined hereinbefore, with a reactive
derivative of an aminothiazolylacetic acid derivative of the formula:
~1 ~ S ~2
N ~ CH2COOH (IIIj
wherein Rl stands for a protected amino grouP; R2 has the
meaning defined hereinbefore, followed, if necessary, by
removal of the protective group. ~he starting compound
(II) for this reaction is put to use with its 4-carboxyl
group being in the form of an alkali metal or organic amine
salt, e g. the sodium, potassium, triethylamine or other
salt, or in the fo~m of an ester which may be converted to
a free carboxyl group under mild conditions, e g. by the
action of a¢id or alkali or by reduction. The ester may be
exemplified by, for example, ~-methylsulfonylethyl, trimethyl-
silyl, dimethylsilenyl, benzhydryl, ~ -trichloroethyl,
phenacyl, p-methoxybenzyl, p-nitrobenzyl or methoxymethyl.
xl in the mating material (III) means an amino group
protected by an easily-removable amino-protective group
which is used in general peptide chemistry, e.g. t-butoxy-
. ~:;... . .
carbonyl, p-nitrobenzyloxycarbonyl~ -trichloroethoxy-
.:
; carbonyl, benzyloxycarbonyl, isobornyloxycarbonyl, etc. or
b~ proton The halogen atom, R2, is normally chlorine or
bromine, for instance. The reactive derivative of starting
compound (III) may for example be the acid halide, acid
- 5 ~
,,: ' . ' ' ~
.
' . ..
-
1064478
anhydride, mixed acid anhydride, active amide or active
ester, Normally this reaction can be conducted smoothly
and with advantage in a solvent. ~he solvent is one which
does not interfere with the reaction, e.g. acetone, tetra-
hydrofuran, dioxane, acetonitrile, chloroform, dichloro-
methane, dichloroethylene, pyridine, dimethylaniline,
dimethylformamide, dimethylacetamide, dimethylsulfoxide or
a mixture of such solvents. While there is no special
limitation on the reaction temperature, the reaction is
normally carried out under cooling or at room temperature.
If necessary, the protective group is removed from the
resultant 7-methoxycephalosporin derivative to produce a 7-
methoxycephalosporin derivative of general formula (I).
As to the removal of protective groups, t-butoxycarbonyl is
removed by acid; ~ -trichloroethoxycarbonyl by reduction
using zinc and acid; p-nitrobenzyloxycarbonyl by catalytic
reduction; for instance. As to the removal of the ester
residue from the 4-carboxyl group, benzhydryl, p~methoxy-
benzyl, etc. are removed by acid; ~-methylsulfonylethyl by
alkalii trimethylsilyl, dimethylsilenyl, etc. by water
alone; ~ trichloroethyl by reduction using zinc and
acid; p-nitrobenzyl, etc. by reduction; for instance. The
removal of these protective groups may be carried out simul-
taneously or, alternatively, one after another, which protec-
tive group should be first removed being determined in con-
sideration of the types of protective groups, the subsequent
reaction and other factors.
The 7-methoxycephalosporin compounds (I) wherein R2
- 6 -
.
. - . . -
'
.
1064478
stands for hydrogen can be also prepared by reacting a
compound of the for~ula:
OCH
hal CH2COCH2CONH ~ ` (IV)
COOH
wherein hal stands for a halogen and R3 has the meanings
defined hereinbefore, with thiourea. The starting material
compound (IV) can be obtained by the reaction of a 7-
aminocephalosporin compound (II) with the 4-halogeno-3-oxo-
butyryl halide which is obtainable bythe reaction of dike-
tene with a halogen such as chlorine or bromine (~ournal of
the Chemical ~ociety 97, 1987(1910)~.
The 7-methoxycephalosporin compounds of formula (V)
can be produced by reacting the above compound (IV) with
~hiourea. This reaction proceeds smoothly in a solvent, e.g.
any of the common solvents which do not interfere with the
contemplated reaction, e g. water, methanol, ethanol, acetone,
dioxane, acetonitrile, chloroform, ethylene chloride, tetra-
,!, .
hydrofuran, eth~l acetate, dimethylformamide, dimethyl-
acetamide or the like or a mixture of such solvents. While
the addition of an acid acceptor is not essential, there
are cases in which the reaction proceeds more smoothly in
the presence of an acid acceptor, provided that the addition
of the particular acceptor does not modify the cephalosporin
,, ~
nucleus. As the acceptor for this purpose, there may be
mentioned inorganic and organic bases such as alkali metal
hydroxides, alkali metal hydrogen carbonates, triethylamine,
pyridine, N,N-dimethylaniline and 50 on. ~he starting
-- 7 --
'
~064478
compound (IV) is subaected to the reaction in the form of
free acid, an alkali metal salt, e g. sodium or potassium
salt, or an ester such as those mentioned hereinbefore in
- connection with the 4-carboxyl group ~ormally the reaction
proceeds adequately at room temperature, although it may be
;: conducted under heating or cooling as required
The compounds (I) may be prepared by reacting a 7-
methoxycephalosporin compound of the formula:
R4 y ~ R2 , 3
N CH2CONH~ f ~
N ~ CH2X ~VI)
COO~
wherein X stands for an acetoxy or carbamoyloxy group; R4
stands for an amino group which may be protected; the other
symbols have the meanings defined hereinbefore with a mercapto
compound, followed, if necessary, by removal of the protec-
tive group The compounds (VI) is normally used in the form
. of the sodium, potassium or other salt at the 4-carbox~l
function
The mercapto compound means, for example, any of
: such alkylmercaptans as methylmercaptan, ethylmercaptan,
butylmercaptan, etc or a heterocyclic compound containing
; a mercapto group. The term, heterocyclic compound, as used
herein means a 5-membered or 6-membered cyclic compound
containing, in addition to carbon, one or several hetero-
atoms such as ~, O or/and S, and when ~ is involved, the
~-oxides are also included. Thus, for example, imidazole,
methylimidazole, pyrazole, triazole, methyltriazole, tetra-
zole, methyltetrazole, oxazole, isoxazole, thiazole,
-- 8 --
.:
. . .
.
..
1064478
isothiazole, oxadiazole, thiadiazole, methylthiadiazole,
pyridine-N-oxide, pyridazine-N-oxide, etc. fall within this
category. Such a mercapto compound, though it may be used
in its free form, is employed with advantage as an alkali
metal salt, e.g sodium or potassium salt. This reaction
is preferably conducted in a solvent. For this purpose,
use is made, for example, of water, heavy water or an
organic solvent which is easily miscible with water and
does not react with the material compounds, e.g. dimethyl-
formamide, dimethylacetamide, dioxane, acetone, alcohol,
acetonitrile, dimethylsulfoxide, tetrahydrofuran or the
like. ~he reaction temperature and time depend upon the
;
particular materials and solvent employed, among other
factors but, generally,may be selected from the range of 0C
to 100C and the range of a few hours to several days, res-
pectively. ~he reaction is preferably carried out in the
~i~ neighborhood of neutrality, i.e. at pH 2 to 8 and, for -
.; . ~.
still better results, at pH 5 to 8. This reaction may at
times be caused to proceed more smoothly by adding a
quaternary ammonium salt having surface activity, e.g.
~rimethylbenzylammonium bromide, triethylbenzylammonium
bromide, triethylbenzylammonium hydroxide or the like, to
the reaction system. More satisfactory results may be
achieved by conducting the reaction in an inert gaseous
atmosphere, e.g. nitrogen gas, so as to prevent atmospheric
oxidation of the mercapto compound.
~he 7-methoxycephalosporin compounds (I) may be
, .
prepared also by reacting a 7-methoxycephalosporin compound
.:~
~ _ 9 _
....
, .
.
, ,j.......... . . . . .
: 106447~3
of the formula:
OCH
; ~/CH(cH2)3coNH ~ R3 (VIII)
CCH2CC~3 COOH
,; .
; wherein the symbol has the meaning defined hereinbefore,
with a reactive derivative of an aminothiazolylacetic acid
derivative of the formula (III) in the presence of a silylat-
~- ing agent and, then, subjecting the reaction product to a
reaction leading to removal of the protected aminoadipoyl
:
group. The 4-carboxyl group of starting material compound
.
(VIII) may be free or have been esterified as in the afore-
mentioned case of compound (II) insofar as the particular
ester is not detrimental to the contemplated reaction.
This reaction comprises reacting a compound (VIII) with a
~ reactive derivative of a compound (III) in a suitable
-i~ solvent~and in the presence of a silylating agent such as
a tri-substituted silyl derivative of a electro-negatively
substituted amide. The reaction can be smoothly conducted
at a temperature of -20C to 50C, normally in the range
of 15C to 45C. ~he solvent may for example be chloroform,
. . ~
~ dichloromethane, acetonitrile or dioxane.
.~, .
P ~he aforementioned negatively substituted tri-substi-
tuted silyl derivative is a compound *hich is synthesized
by reacting a electro negatively substituted amide or imide
with a tri-substituted silyl halide. As said amide or
` imide, there may be mentioned succinimide, phthalimide,
cyanoacetamide, trifluoroacetamide, trichloroacetamide and
, .~ .
- 10
, .
... .
.
, . . . ' ' , ': . ';;. , . ' .. ' ' ' ''. .. ;,, : . . '
`\
1064478
so on, Particularly useful for the contemplated reaction
are N-trimethylsilyltrifluoroacetamide and N-trimethylsllyl- '
phthalimide. ~he resultant reaction product, as it OCCUr5
in the reaction mixture or after a suitable treatment such
as concentration or isolation, is subaected to a reaction
leading to removal of the protected aminoadipoyl group.
~his reaction is normally conducted under conditions similar '
... .
to those used for removal of ~ -trichloroethoxycarbonyl.
' Thus, for example, it comprises the reaction with zinc and
;' aqueous acetic acid or aqueous formic acid, The reaction
can normally be accomplished satisfactorily at room tempera-
' ture, the range of 10 to 40C being useful.
~he 7--methoxyoephalosporin compounds (I) as obtained
` by the processes thus far described in detail can be purified
by E~ se conventional procedures, e g. column chromatography,
extraction, precipitation, recrystallization and so on.
The am~Noth~azolylaGe*ic acid derivatives (III) can
';Y be prepared by, for example, reacting a chloroformic acid 2- -
~ halogénoethyl ester with thiocyanate to obtain a 2-halogeno-
:, .
~ ethoxycarbonyl isothiocyanate, reacting thus obtained compound
.-
with ammonia to obtain an ~-(2-halogenoethoxycarbonyl)thiourea,
- reacting the compo.und with an ~-halogenoacetoacetic acid alkyl
.. .. .
'~ ester~to gïve a 2-(2'-halogenoethoxycarbonylamino)thiazol-4-
~ ~lacetic acid alkyl ester and hydrolyzing the alkyl ester
~( . .
to obtain a 2-(2'-halogenoethoxycarbonylamino)th~zol=4-
ylacetic acid. Alternatively, the 2-(2'-halogenoethoxy-
carbonylamino)th'iazol-4-ylacet d acid may be prepared by
'~ reacting an 2-aminothiazol-4-ylacetic acid alkyl ester with
. : , .
.
:.k.~, ' -- 11 --
' ~ '' ' ' ''
" ''' ' ' .
~o644q8
a chloroformic acid 2-halogenoethyl ester and hydrolyzing
thus obtained 2-(2'-halogenoethoxycarbonylamino)th~azol-
; 4-ylacetic acid alkyl ester.
Ifhe following description pertains, in the first
place, to the process comprising reacting an ~-(2-halogeno-
ethoxycarbonyl)thiourea with aff~-haloacetoacetic acid
alkyl ester One of the reactants, an ~-(2-halogenoethoxy-
carbonyl)thiourea, is prepared by reacting a chloroformic
acid 2-halogenoethyl ester with thiocyanate and adding
~ ammonia to the resultant 2-halogenoethoxycarbonyl isothio-
- cyanate. This compound is a novel compound which has never
been described in the literature. The halogen, substituting
the 2-position of the ethyl group of said chloroformic acid
ethyl ester, may for example be chlorine, bromine or/and
fluorine, and one to three such halogen atoms may be present
as substituents. Thus, trichloro-, dibromo and other com-
pounds are commonly employed. Thiocyanic acid, for the
~ purposes of this reaction, may be used in its free form,
."..
although normally it is more conveniently reacted as one
of the salts of alkali metals, e,g~ sodium, potassium, etc.,
,. .
the salts of heavy metals, e.g. copper, lead, etc., the
ammonium salt and so on. This reaction proceeds smoothly
in a solvent. The solvent to be normally employed is pre-
ferably a nonprotonating solvent, such as, acetone, ~ethyl
ethyl ketone, tetrahydrofuran, dioxane, acetonitrile, ether,
~ benzene or toluene. Advantageously the reaction is conducted
,~ at a low temperature so as to avoid undesirable side reac-
tions. Normally the reaction can be conducted smoothly
,
: '
- 12 -
~'..' ,
-
::
1064478
within the range of 5C to -20C.
The 2-halogenoethoxycarbonyl isothiocyanate thus
,;, .
obtained is so reactive that it is normally not isolated
but the reaction mixture as such is subjected to the next
treatment, i.e. reaction with ammonia, to produce an ~-(2-
halogenoethoxycarbonyl)thiourea. This ammonia-addition
reaction may be carried out by introducing ammonia into the
reaction mixture obtained in the aforementioned production
stage for 2-halogenoethoxycarbonyl isothiocyanate, but
normally the metal halide or ammonium halide by-produced from
a chloroformic acid 2-halogenoethyl ester and a thiocyanate
salt is first separated by filtration and, then, ammonia
is introduced into the filtrate. The ammonia may be added
in gaseous state, or a solution of ammonia in a suitable
:. .
solvent, e.g. methanol or ethanol, may be introduced. The
reaction is preferably carried out at a low temperature,
normally within the range of 5C to -10C
The reaction of an ~-haloacetoacetic acid compound
with an N-(2-trichloroethoxycarbonyl)thiourea to produce a
2-(2'-trichloroethoxycarbonylamino)thiazol-4-ylacetic acid
is normally conducted with advantage in a solvent and in
the presence of a base. ~he solvent just mentioned may be
any solvent that is able to dissolve the two starting
materials and, at the same time, will not interfere with
the contemplated reaction. Thus, use may be made of alcohols
such as methanol, ethanol, propanol, etc.; ketones such as
acetone, me~hYl ethyl ketone, etc.; ethers, such as ether,
tetrahydrofuran, dioxane, etc. and their mixtures, to name
, '~
- 13 -
'
.
.
., , ~ ~ :
1064478
but a few. ~hls reaction proceeds smoothly in the presence
of a base. As the base, there may be mentioned organic
tertiary bases such as pyridine, picoline, quinoline,
isoquinoline, triethylamine, tributylamine, ~-methyl-
piperidine, N-methylmorpholine, N,N-dimethylaniline, N,~-
diethylaniline and so on, The reaction proceeds at room
temperature but, there are cases where the reaction is
hastened by heating. The heating temperature in the neighbor-
hood of the boiling point of the solvent employed is normally
advantageous, As to the mating starting material, i~e. an
~-haloacetoacetic acid alkyl ester, there may be employed
methyl ~-chloroacetoacetate, ethyl ~-chloroacetoacetate,
.~ ,~. .
methyl ~-bromoacetoacetate, ethyl ~rbromoacetoacetate and other
; ~ -halogenoacetoacetic acid alkyl esters.
The following description pertains to the process
which comprises reacting an 2-aminothiazol-4-ylacetic acid
alkyl ester with 2-trichloroethyl chloroformate to produce
a 2-(2'-halogenoethoxycarbonylamino)thiazol-4-ylacetic
acid alkyl ester. This reaction is normally conducted
smoothly in a solvent and in the presence of a base. The
solvent may be any solvent that will not interfere with
. ~ .
the contemplated reaction. Normally,use is made of a non-
protonating organic solvent such as, chloroform, dichloro-
; .:
methane, dichloroethylene, carbon tetrachloride, chloro-
benzene, ether, tetrahydrofuran, dioxane, acetone or methyl
,,
~ ethyl ketone, or a mixture of such solvents. The base may
!~
~ be any base that is able to accept or combine with the
~ .
~ hydrogen halide by-produced in the course of the reaction
~, .
.
~ - 14 -
:` ~
:
~ ~064478
i. ~, . .
and that does not interfere with the reaction, ~hus,
normally, organic tertiary bases such as pyridine, picoline,
quinoline, isoquinoline, triethylamine, tributylamine, N-
methylpiperidine, ~-methylmorpholine, N,N-dimethylaniline
or ~,N-diethylaniline, may be employed. While the reaction
proceeds smoothly at room temperature, the reaction system
.
- ~ may be cooled or heated as occation requires.
The 2-(2'-halo~enoethoxycarbonylamino)thiazol-4-
ylacetic acid ester thus obtained is partially hydrolyzed
to a 2-(2'-halogenoethoxycarbonylamino)thiazol-4-ylacetic
acld~ This hydrolysis reaction is carried out in a solvent
and in the presence of a base. The solvent is preferably
one that is able to dissolve both the starting material
ester and the base. Thus, normally, a mixture of water and
an organic solvent miscible with water, such as methanol,
ethanol, acetone or tbe like, is employed. As the base,
use is~normally;made of an inorganic strong base such as,
sodium:hydroxide, potassium hydroxide or barium hydroxide.
his reaction is~conducted with advantage at a temperature
`near ro~om~temperature~so as to~avoid occurence of undesirable
side reactions.~
,.Z~
he;present inv~ention is illustrated in further detail
~s~ below with reference~to examples, but it is to be under-
stood that the examples are solely for the purpose of
;illustratlon and not to be construed as limitations of the
,. . ~
invention, and that many variations may be resorted to
wlthout departlng from the spirlt and scope of the inven-
p~ tion. In this specification, "g.", "mg.", "m~", "cm.",
; ~ - 15 -
- :. . -
~.. - . .. , ~ . . . .. -
.. . . . . .
~ . : . , ~ . . . :
:~.. : , - . ... .
' : . ' ' . '
, ! , . . . .
-
1064478
"ppm", and "Mc" are abbreviations of "gram", "milligram",
"millili~er"9 "cen~im~ter"9 "part pe~ million"9
and "megacycle", repsectively. Resins named "Amberlite"
are products manufactured by Rohm & Haas Co, in U.S.A.
All the temperatures are uncorrected and the percentages
are all on the weight basis except specifically defined.
~I) Preparation of 2-(2',2',2'-trichloroethoxycarbonyl-
amino)thiazol-4-ylacetic acid
(1) In 250 ml of acetone was dissolved 25.2 g. of potassium
thiocyanate and while the solution was cooled at -20C, 50 g.
of 2,2,2-trichloroethyl chloroformate was added dropwise.
;~ 1; `
After the dropwise addition had been completed, the mixture
was stirred at that temperature for 30 minutes. ~he preci-
pitated potassium chloride was filtered off. ~o the filt-
rate was added 26 g. of 17 % methanolic ammonia at -10C.
he mixture was stirred for 45 minutes, after which the
.,1.~, ;: . : -
solvent was distilled off. ~he syrupy residue was recrystal-
lized from aqueous methanol to obtain 21.8 g. of N-(2,2,2-
trichloroethoxycarbonyl)thiourea as colorless prisms melting
at 189-190-C.
Elemental analysis, for C4H5C~3N202S:
Calculated C, 19.10; H, 2.00; N, 11.14
Found C, 19.22; H, 1.96; N, 11.50
(2) In 3 m~ of ethanol was dissolved 500 mg. N-(2,2,2-
trichloroethoxycarbonyl)thiourea, 416 mg. ethylo~-bromo-
. : .
acetoacetate and 363 mg. N,~-dimethylaniline and the solu-
tion was stirred at room temperature for 24 hours. After
the solvent was distilled off under reduced pressure, the
- 16 -
',
.. . . . ... . . .
.. .. . .: , .
;
: 1064478
residue was dissolved in chloroform and washed once with
10 % hydrochloric acid and, then, three times with a
saturated aqueous solution of sodium chloride. After drying
over magnesium sulfate, the chloroform layer was concentrated
and the oily residue was passed through a column of silica
gel a~d eluted with a 1:1 mixture of benzene and chloroform
The above isolation-purification procedure provided 540 mg.
of ethyl 2-(2',2',2'-trichloroethoxycarbonylamino)thiazol-
4-ylacetate, melting point: 91-92C
Elemental analysis, for CloHllC~3~204S:
Calculated C, 33,21; H, 3.07; N,7.75
~ound C, 33.38; H, 2.85; ~,7.73
(3) In 3 ml of acetone were dissolved 500 mg. N-(2,2,2-
trichloroethoxycarbonyl)thiourea, 328 mg. ethyl ~-chloro-
acetoacetate and 237 mg. pyridine and the solution was
stirred at room temperature for 24 hours. ~hereafter, the
treatment similar to Example 2 gave 502 mg. of ethyl 2-(2',
2',2'-trichloroethoxycarbonylamino)thiazol-4-ylacetate.
~his product was identified with the compound prepared
according to the procedure described above (2).
(4) In 100 ml of dichloromethane were dissolved 18.6 g,
: . ~
ethyl 2-aminothiazol-4-ylacetate and 11.1 g. triethylamine
and, while the solution was cooled with ice, 23.3 g. of
2,2,2-trichloroethylchloroformate was added dropwise.
A~ter the dropwise addition had been completed, the mixture
,
;~ was stirred for 1 hour, at the end of which time 50 m~ of
~: .
- water was added to the reaction mixture.
The organic layer was taken, washed twice with 10
:
''`'''~:
- 17 -
.,,,
.. ,, , . .. , , . , - .: : . : ~ :
:
1064478 : ~
-, . :
hydrochloric acid and once with water, then washed once
with 10 Yo aqueous sodium hydrogen carbonate solution and
twice wlth saturated aqueous sodium chloride solution.
Then, after drying over magnesium sulfate, the magnesium . ' '
sulfate was filtered off and the dichloromethane was removed
by distillation. To the resultant oily residue was added - '
80 me of ethanoi and the.precipitate was filtered off
;(un~reacted~ethyl 2-aminothiazol-4-ylacetate: 9.7 g.). The :~
filtrate:wa~s ¢oncentrated and passed through a column of :-'"
8i11ca~gel~and eluted with a 1:1 mixture of chloroform and
benzene~ he above isolation-purification procedure provided ; .~:
12.~2~g ~ of ethyl 2-(2'j2',2'-trichloroethoxycarbonylamino)~
thiaz.ol-4-ylacet.ate. This pr.~oduct.:was identified with the ~ '
compound prepared according to (2) above.
1: . J~
5)~ ~In a mixture of 50 me water and 50 m~ methanol were . .
d~'~8solved~5.9~~g~. of~ethyl~2-(2'',2~'',2''-trichloroethoxycarbonyI-
n~m ~i);t.hiaz.ol.-4:~ylacetate.~and~ 3.~g .of= sodi~m hydroxide ''"
andj~the:~solution~was:~stlrred:at room temperature for 4 hours.
A~:ma3'or;portion:of~the mlethanol~wa~distilled.off under .
e ~ ed pre~s~u're~an~t~e~'resid~e~was~wàshed wIth 20 me ethyl
ac~etate,~made~acidio~:wlth lO y:~hydrochlorlc acid and extracted
twice~with~5o~me port:ions of ether The ether extract was
s:h~cd~with w.'ater,~dried-~and concentr'àted. The procedure
pPoVided 3~ g :~of 2-(2~',2'-,~2'-trichloroethoxycarbonylamino)-
thiazol-4-ylacetic acid,~:~melting:;~polnt: 164-164~5C.
Elemental~analysls, for c8H7ce3 ~ 04S: .
CalGulat:ed C, 28.81; H:, 2.12;.N, 8.40
Found C,. 28..92;. H, 2 20; N, 8.44
, .. , ~ ., .
r, ~. : i
1064478
(II) Preparation of 2~ -trichloroethoxycarbonylamino)-
5-chlorothiazol-4-ylacetyl chloride hydrochlorlde
(1) ~o a suspension of 5 g. of 2-(~ -trichloroethoxy-
carbonylamino)thiazol-4-ylacetic acid in 75 m~ of chloro-
form, was added dropwise 14 9 m~ of a 10 /0 (weight per
- volume) chlorine solution in dichloromethane. In 5 minutes
after the completion of the addition, the mixture became a
- complete solution and was stirred for further 15 minutes,
followed by extracting three times with 50 m~ each of a 5 %
aqueous solution of sodium hy-drogencarbonate. ~he extracts
, :'
~-~ were combined and acidified with diluted hydrochloric acid
to precipitate 2~ trichloroethoxycarbonylamino)-5-
chlorothiazol-4-ylacetic acid. ~he precipitates were
i collected by filtration and recrystallized from chloroform-
~,.
;~ ether to give 3.5 g. of pure compound as colorless crystals
melting at 112.0C
Elemental analysis, for C8H604H2C~4S
Calculated C, 26 10; H, 1.64; ~,7 61
Found C, 25.96; H, 1.80; ~,7.25
(2? To a suspension of 4~2 g. of 2~ -trichloro-
ethoxycarbonylamino)-5-chlorothiazol-4-ylacetic acid in
10 m~ of dichloromethane, was added 2 38 g of phosphorus
pentachloride and the mixture was stirred for 30 minutes
at room temperature to precipitate 2-(~ -trichloro-
:
~ ~ ethoxycarbonylamino)-5-chlorothiazol-4-ylacetyl chloride
., ., ~
hydrochloride The precipitates were collected by filtra-
tion and washed with a small amount of dichloromethane.
Yield 3.38 g. colorless powder. Melting point: 99.8C.
-- l 9
: ';
.~ . ., .. . , . . .. .. , .. ~ . . . .. - - ... - .. . . - .- . .
. . . . . .... .. . .. . ., . . , . . . , . . . . . .
~ , . . .. ~. .
1064478
,
Elemental analysis; for C8H503N2C~5S~HC~
Calculated C, 22.72; H, 1.43; H, 6,62
Found C, 23.L~4; H, 1.63; N, 6.77
(III) Preparation of 7-methoxycephalosporin derivatives
;
Example 1
(1) In 20 m~e of dichloromethane was suspended 6.67 g. of
-; 2-(B,~ trichloroethoxycarbonylamino)thiazol~-ylacetic
acid and, while the suspension was stirred under cooling
with ice, 4.15 g. of finely crushed phosphorus pentachloride
~` ' was added, whereupon the suspended acid was completely
dissolved. ~hen, after an elapse of about 5 minutes, fresh
crystalline substance separated. ~he mixture was stirred
at room temperature for 1 hour, after which time the preci-
pitates were collected by filtration and rinsed with petro-
leum ether ~he procedure provided 6,59 g. (yield 84,8 %)
of 2-(,B,,13,~-trichloroethoxycarbonylamino~thiazol-4-ylacetyl
chloride.hydrochloride~ melting point: 109 7C (decomposition)
Elemental analysis, for C8H603N2C~4$-HC~
Calculated C, 24.73; H, 1.81; N, 7.21
Found C, 24.40; H, 1.63; N, 6.94
(2) In 10 m~ of dichloromethane was dissolved 1.638 g.
of benzhydryl 7a-methoxy-7~-aminocephalosporanate and,
while the solution was cooled with ice, 1.5 m~ of pyridine
and, immediately thereafter, 2.70 g. of 2-(,B,B,~-trichloro-
ethoxycarbonylamino)thiazol-4-ylacetylchloride.hYdrochloride
were added. The mixture was stirred for 15 minutes. It
was further stirred at room temperature for 20 minutes,
after which it was poured in ice-water and extracted with
` - 20 -
, .
.. : . .: ., . :
.
, . . .
.
1064478
`~"
ethyl acetate. The ethyl acetate layer was washed with
0.5~ hydrochloric acid, water, a 5 /0 aqueous sodium hydrogen
carbonate solution and a saturated aqueous sodium chloride
... .
solution in the order mentioned, followed by drying over
magnesium sulfate. ~hereafter, the ethyl acetate was dis-
tilled off to obtain an oily residue. ~he oil was purified
by chromatography on silica gel. The above procedure
provided 1.096 g.(yield 39.9 %) of benzhydryl 7a-methoxy-
7~-(2-(~ -trichloroethoxycarbonylamino)thiazol-4-ylacet-
amido)cephalosporanate.
~ he infrared absorption spectrum (KBr)of this product
shows an absorption of ~-lactam at 1770 cm l. The nuclear
magnetic resonance spectrum (60 Mc, in deuteriochloroform)
.,
- ~ of the product shows a singlet assignable to the ~-acetyl
group at 1.98 ppm, a singlet due to 2-methylene protons at
. .
.33 ppm, a singlet due to 7a-methoxy at 3.34 ppm, a singlet
~; assignable to the methylene protons of the thiazolylacetic
...,~
acid moiety at 3.74 ppm, a singlet due to the methylene
protons of trichloroethoxycarbonyl at 4,84 ppm, a quartet
due to 3-methylene protons at 4.90 ppm, a singlet of the
:
6-hydrogen at 5.05 ppm, a singlet assignable to the 5-
` ~; hydrogen of the thiazole ring at 6.57 ppm, a singlet
assignable to the methine protons of benzhydryl at 6.85
ppm, and a singlet due to the phenyl protons of benzhydryl
at 7.30 ppm.
.. .
; (3) In 25 m~. of 9~/0 formic acid was dissolved 990 mg.
of benzhydryl 7~-methoxy-7~2~ -trichloroethoxycarbonyl-
-~ amino3thiazol-4-ylacetamido~cephalosporanate and, after the
'':
- 21 -
., , . : . ,, ~ , ., . . .: : . .
-
1064478
addition of 860 mg zinc dust under cooling with ice, the
mixture was stirred for 1 hour. The reaction mixture was
poured in a saturated aqueous solution of sodium chloride
and extracted with ethyl acetate. The ethyl acetate layer
was washed with water, a 5 /c aqueous sodium hydrogen carbonate
solution and a saturated aqueous sodium chloride solution
in the order mentioned, followed by drying over magnesium
sulfate. ~hereafter? the ethyl acetate was distilled off
., .
- to obtain 472 mg. (yield 61.5 %) of benzhydryl 7-methoxy-
7~-(2-aminothiazol-4-ylacetamido)cephalosporanate. The
infrared absorption spectrum of this product shows an
absorption of ~-lactam at 1770 cm 1.
; . .
,~ The nuclear magnetic resonance spectrum (60 Mc, in
. . ~
~ deuteriochloroform) of this ester shows a singlet assignable
,. . .
to the 3-acetyl group at 2.00 ppm, a quartet due to 2-methyl-
t ~ ene protons at 3.36 ppm, a singlet due to 7-methoxy at 3.45
~- ppm, a singlet assignable to the methylene protons of thia-
zolyl acetic acid at 3.56 ppm, a quartet assignable to 2-
,., ~
methylene protons at 4.90 ppm, a singlet due to 6-hydrogen
at 5.08 ppm, a singlet assignable to the 5-hydrogen of the
thiazole ring at 6.28 ppm, a singlet due to the methine
protons of benzhydryl at 6.93 ppm and a singlet due to the
phenyl nuclear protons of benzhydryl at 7.30 ppm.
(4) Under cooling with ice and stirring, 335 mg. of benz-
hydryl 7~-methoxy-7~-(2-aminothiazol ~I-ylacetamido)cephalos-
poranate was added to a mixture of 1.5 ml trifluoroacetic
acid and 1.5 m~ anisole and the mixture was stirred for 30
minutes. The reaction mixture was poured in 50 m~ anhydrous
,, .
.~ .
- - 22 -
.
~i . . . .. .
: 1064478
' ether and the resultant white precipitat~s llere collected- ~ and rinsed with ether. The proced~re provided crude 7a-
- methoxy-7~-(2-aminothiazol-4-ylacetamido)cephalosporanic
-`, acid trifluoroacetate (185 mg.). This product was dissolved
in a 5 % aqueous solution of sodivm hydrogen carbonate and
the solution was run onto a column of Amberlite XAD~2(trade
name) and eluted wi-th water. ~his purifica-tion procedure
provided 131 mg. (50.8 %) of sodium 7a-methoxy-7~-(2-
; aminothiazol-4-ylacetamido)-cephalosporanate.trihydrate.
';; , ~lemental analysiS 9 for C16H1707N4S2Na 3H20
, .
Calculated ~, 37,o6~9 H9 4.47%; N9 10~80~o
~'ound Cs 37.36c,~9 ~, 4,14%9 N9 10.50%
,' ~he nuclear resonance spectrum (100 Mc9 in D20) of
~' this product showed a singlet due to 3-acetyl at 2.26 ppm9
quartet ~ssignable to 2-methylene protons at ~.52 ppm9 a
~ singlet assignable to 7-methoYy at ,3.70 ppm9 a singlet
- , assignable to the methylene protons o~ thiazolylacetic acid
,; , function at 3.80 ppm9 a quartet due to 3-methylene pro-tons
at 4.95 ppm, a singlet due to 6-hydrogen at 5.32 ppm and a
~' singl0t assignable to the 5-hydrogen of the thiazole ring
-' at 6.70 ppm.
~ (5) ~he ~ollowing compounds were prepared by a similar
,~, manner as above Example; 7~-methoxy-7~-(2-aminothiazol-4-
.
," ylacetamido)-3-methoxymethyl-3-cephem-4-carboxylic acid9
7~methoxy-7~-(2-aminothiazol-4-ylacetamido)-3-(2-carbogyl-
''~ ethenyl)-3-cephem-4-carboXYlic acid9 7~-metho~y 7~-(2-
~' aminothiazol-4-ylacetamido)-3-methylthiomethyl-3-cephem-4-
: ca~boxylic acid.
xamPle ?
(1) In 4 m~ of water containing 208 mg. of sodium hydrogen
. .
... .
. ' , .
` 1064478
carbonate, there were dissolved 431 mg. of 7~-methoxy-7~-
(2-aminothiazol-4-ylacetamido)cephalosporanic acid-trifluo-
roacetate, 108 mg. of 1-methyl-lH-tetrazole-5-thiol and
24.6 mg. of triethylbenzylammonium bromide, and the reaction
mixture was stirred at 60C for 6 hours in an atomosphere
of nitrogen gas. After cooling, the reaction mixture was
passed through a column of Amberlite XAD-2(trade name) and
eluted with water ~he above purification procedure provided
158 mg. (36.8 %) of sodium 7-methoxy-7~-(2-aminothiazol-4
ylacetamido)-3-(1-methyl-lH-tetrazol-5-ylthiomethyl)-3-
~ ,;
~ ~ cephem-4-carboxylate.
!,.' Elemental analysis, for C16H1705N8SNa.H20
~ Calculated C, 35.68; H, 3.55; N, 20.86
;"
~ound C, 35.56; H, 3.36; N, 19.83
The infrared absorption spectrum (KBr) of this product
showed an absorption of ~-lactam at 1750 cm 1. The nuclear
:;i ~,
,,b~ magnetic resonance spectrum (100 Mc, in D20) of the same
. ~
product showed a quartet assignable to 2-methylene protons
at 3.60 ppm, a singlet due to 7-methoxy at 3.65 ppm, a
singlet due to the methylene protons of thiazolylacetic
acid function at 3.77 ppm, a singlet assignable to tetrazole-
methyl protons at 4.17 ppm, a quartet assignable to 3-methyl-
ene protons at 4.30 ppm, a singlet assignab~e to 6-hydrogen
at 5 24 ppm and a singlet due to the 5-hydrogen of the
thiazole ring at 6.67 ppm.
(2) The same procedure as (l)in the absence of triethyl-
benzylammonium bromide also gave sodium 7-methoxy-7~-
(2-aminothiazol-4-ylacetamido)-3-(1-methyl-lH-tetrazol-5-
- 24 -
.
.,, , , :
.. : . . ,
1064478
ylthiomethyl)-3-cephem-4-carboxylate salt. This product
was identical with the compound obtained in (1).
.:
Example
In 20 m~ of dichloromethane was dissolved 2 62 g. of
benzhydryl 7~-methoxy-7~-amino-3-(1-methyl-lH-tetrazol-5-
ylthiomethyl)-3-cephem-4-carboxylate and,under cooling -
with ice, 3 0 m~ of pyridine and, then, 3,88 g ol 2~(~
trichloroethoxycarbonylamino)thiazol-4-ylacetyl chloride-
hydrochloride were added ~he mixture was stirred for 15
minutes and, then, at room temperature for 20 minutes
~hereafter, the reaction mixture was poured in ice-water
.,
and extracted with ethyl acetate. The ethyl acetate layer
was washed with 0 5N hydrochloric acid, water and a saturated
aqueous sodium chloride solution in the order mentioned,
followed by drying over magnesium sulfate. The ethyl acetate
was distilled off to obtain an oily residue. ~his oil was
purified by chromatography on silica gel. ~he procedure
provided 1.82 g. (43 %) of benzhydryl 7a-methoxy-7~-~2-
trichloroethoxycarbonylamino)-thiazol-4-ylacetamido)-
3-(1-methyl-lH-tetrazol-5-ylthiomethyl)-3-cephem-4-carboxy-
late. A 1.50 g portion of this ester was dissolved in
40 m~ of 90 /0 formic acid and, under cooling with ice and
stirring, 1.30 g of zinc dust was added The reaction
mixture was thus stirred for 1 hour. The reaction product
was poured in a saturated aqueous solution of sodium
chloride and extracted with ethyl acetate. ~'he ethyl
acetate layer was washed with water and a saturated aqueous
sodium chloride solution, followed by drying over magnesium
'
l - 25 -
.:
: - . . . . . . .
`' ~ ` ' ' ` ' ' ` `' '" " ~ " " " " ' ` ' ' `` `' '
: ~ ' ' ' ` ' ` : ''' ,
~ `
~ 1064478
sulfate, The ethyl acetate was distilled off to obtain 753
mg. (63,4 %) of crude benzhydryl 7a-methoxy-7~-(2-aminothia-
zol-4-ylacetamido)-3-(1-methyl-lH-tetrazol-5-ylthiomethyl)-
' 3-cephem-4-carboxylate.
A 700 mg. portion of this product was added to a
mixture of 3.0 ml trifluoroacetic acid and 3.0 m~ anisole
and, under cooling with ice and stirring, the reaction was
carried out under cooling with ice and stirring. ~he reac-
-~ tion mixture was poured in 100 m~ of anhydrous ether and
~ the resultant precipitates were collected by suction and
,~; rinsed with ether. ~he procedure provided 373 mg. of 7~- :
methoxy-7~-(2-aminothiazol-4-ylacetamido)-3-(1-methyl-lH-
~, . . .
tetrazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid-trifluo-
roacetate, Thls product was dlssolved ln a 5 % aqueous
solution of sodium hydrogen carbonate and passed through a
column of Amberlite XAD-2 (trade name), followed by elution
with water~ ~he above purification procedure provided 303
mg, of sodium 7a-methoxy-7~-(2-aminothiazol-4-ylacetamido)-
. , .,:
3-(1-methyl-lH-tetrazol-5-ylthiomethyl)-3-cephem-4-carboxy-
late.
This product was completely identical with the product
~-; obtained in Example 2.
Example 4
In 2 m~ of water containing 95 mg. of sodium hydrogen
carbonate were dissolved 200 mg, of 7a-methoxy-7~-(2-amino-
thiazol-4-ylacetamido)cephalosporanic acid-trifluoroacetate
and 59 mg. of 6-methylpyridazine-3-thiol l-oxide, followed
- by the addition of 11 mg. triethylbenzylammonium bromide.
,,,
~ - 26 -
;1,.
,:
.. .
, . ., :
. . ~
. .
, . -
- :
.
'
1064478
The mixture was stirred in an atmosphere of nitrogen gas
at 60C for 6 hours. After cooling, the reaction mixture
was passed through a column of Amberlite XAD-2(trade name),
followed by elution with water. The above purification
procedure provided 62 mg. (yield 31.6 %) of 7a-methoxy-7~-
(2-aminothiazol-4-ylacetamido)-3-(6-methylpyridazin-~-
ylthiomethyl)-3-cephem-4-carboxylic acid l-oxide sodium salt.
~lemental analysis, for C19H1906~6S3Na 4.5H20
Calculated C, 36.36; H, 4.58; ~, 13.39
~ound C, 36.12; H, 3.96; N, 12.64
~he infrared absorption spectrum (KBr) of this product
~;
showed an absorption of ~-lactam at 1760 cm 1. The nuclear
magnetic resonance spectrum (100 Mc, in D20) showed a singlet
assignable to the methyl protons on the pyridazine ring at
2.61 ppm, a quartet due to 2-methylene protons, a singlet
due to 7-methoxy-protons at 3.65 ppm, a singlet of the
methylene protons of the thiazolylacetic acid function at
3.77 ppm, a singlet due to 6-hydrogen at 5.24 ppm, a singlet
assignable to the 5-hydrogen of the thiazole ring at 6.67
ppm and a doublet assignable to pyridazine ring protons at
7.51 and 7 88 ppm, respectively.
Example 5
In 10 m~ of water containing 184 mg. of sodium hydrogen
carbonate were dissolved 556 mg. of 7a-methoxy-7~-(2-amino-
. . .
; thiazol-4-ylacetamido)cephalosporanic acid-trifluoroacetate,
185 mg. of 2-methyl-1,3,4-thiadiazole-5-thiol sodium salt
and 30 mg of triethylbenzylammonium chloride and the solu-
tion was stirred in nitrogen streams at 58C for 6 hours.
. .
~ - 27 -
''~
. ' .
~ ;~ . , . . . . .. . -.. . : . ... . ,, . . :, . . : , . - .,- ,
~ 1064478
After cooling, the reaction mixture was passed through a column
.
of Amberlite XAD-2 (trade name), elution being carried out with
water. Upon this purification treatment, there was obtained 121
mg. (yield 22.5%) of sodium 7~-methoxy-7~-(2-aminothiazol-4-ylacet-
amido)-3-(2-methyl-1,3,4-thiadiazol-5-ylthiomethyl)-3-cephem-4-
-.~
~ carboxylate.
.~........................................................................... .
Example 6
; In 20 mQ of dichloromethane was dissolved 953 mg. of .
'; benzhydryl 7~-methoxy-7~-(D-5-trichloroethoxycarbonylamino-5-
benzhydryloxycarbonylvalerylamino)cephalosporanate, followed by
the addition of 740.8 mg. of N-trimethylsilyltrifluoroacetamide
and 1555.4 mg. of 2-(~ -trichloroethoxycarbonylamino)thiazol-
~;~ 4-ylacetylchloride-hydrochloride. The mixture was heated at 41C
with stirring for 24 hours. After cooling, the reaction mixture
was filtered to remove the insoluble matters and the filtrate
, ~ was concentrated under reduced pressure. The residue, which was
; crude benzhydryl 7~-methoxy-7~-[(D-5-trichloroethoxycarbonylamino-
... ..
! 5-benzhydryloxycarbonylvaleryl~-(2-~ -trichloroethoxycarbonyl-
aminothiazol-4-ylacetyl)amino]-cephalosporanate, was dissolved in
10 mQ of 90% formic acid. After the addition of 4 g. of zinc
dust, the solution was stirred at room temperature for 5 hours
` and, then, filtered. To the filtrate was added 5 mQ of a saturated
` ~ sodium chloride solution followed by extraction with ethyl acetate.
.~ .. . .
.;~ .
The ethyl acetate layer was washed with water and dried over
magnesium sulfate. The ethyl acetate was then distilled off and
the oily residue was purified by chromatography on silica gel.
..
; ; - 28 -
.
.
- :
,; ~.
.
- .
-:
`` 1064478
The procedure provided 197 mg. (32,4%) of benzhydryl 7
methoxy-7~-(2-aminothiazol~4-ylacetamido)cephalosporanate.
This product was identical with the product obtained in Example
1 (3).
~ Example 7
; In 20 mQ of acetonitrile was dissolved benzhydryl 7-
methoxy-7~-(D-S-trichloroethoxycarbonylamino-5-benzhydryl-
oxycarbonylvalerylamino)-3-carbamoyloxymethyl-3-cephem-4-
carboxylate, followed by the addition of 876.3 mg. of N-tri-
.,
methylsilylphthalimide and 1555.4 mg. of 2-(~ -trichloro-
ethoxycarbonylamino)thiazol-4-ylacetyl chloride-hydrochloride.
The mixture was stirred under heating at 41C for 24 hours.
After the reaction mixture was cooled, the insoluble matters
were filtered off and the filtrate was concentrated under re-
duced pressure. The resultant residue, i.e. crude benzhydryl
7-methoxy-7~-[(D-trichloroethoxycarbonylamino-5-benzhydryl-
oxycarbonylvaleryl)-(2-trichloroethoxycarbonylaminothiazol-4-
;i
ylacetyl)amino]-3-carbamoyloxymethyl-3-cephem-4-carboxylate,
was dissolved in 10 mQ of 90% acetic acid. After the addition
of 4 g. zinc dust, the solution was stirred at room temperature
; ~ for 8 hours. It was then filtered and 10 mQ of saturated -
' ~ aqueous sodi D chloride solution was added to the filtrate.
The mixture was extracted with ethyl acetate, washed with water
and dried. The oily product from the ethyl acetate layer was then
-, purified by chromatography on silica gel. The procedure pro-
. j ,
~- vided 120 mg. of benzhydryl 7~-methoxy-7~-(2-aminothiazol-
4-ylacetamido)-3-carbamoyloxymethyl-3-cephem-4-carboxy-
.;
. .. . .. . ... ..... . . .. ... .. ...... . . . . . .. . . .. .
;- 1064478
`
late. Under cooling with ice, the above product was added
to a mixture of 0 75 m~ trifluoroacetic acid and 0.75 m~
anisole and the mixture was stirred for 30 minutes, followed
by the addition of 50 m~ anhydrous ether. ~he resultant
precipitate was collected by suction, rinsed with ether and
dissolved in a 5 % aqueous solution of sodium hydrogen
carbonate. ~he solution was passed through a column of
Amberlite XAD-2(trade name), elution being carried out
with water. Upon this purification, there was obtained
sodium 7a-methoxy-7~-(2-aminothiazol-4-ylacetamido)-3-
carbamoyloxymethyl-3-cephem-4-carboxylate.
:
Exam~le 8
In 30 m~ of chloroform was dissolved 2.05 g. of benz-
hydryl 7a-methoxy-7~-amino-3-desacetoxycephalosporanate and,
~; under cooling with ice 3.0 m~ of pyridine and, then, 3.88 g.
of 2-(~ -trichloroethoxycarbonylamino)thiazol-4-ylacetyl
.,., ~
chloride-hydrochloride were added. ~he mixture was stirred
for 15 minutes. Then, at room temperature, the mixture was
, . ..
further stirred for 20 minutes. ~hen, it was poured in 20
m~ of ice-water and extracted with ethyl acetate. The ethyl
acetate layer was washed with 0.5~ hydrochloride, water
and saturated aqueous sodium chloride solution, followed
by drying over magnesium sulfate. The ethyl acetate was
distilled ofX to obtain an oily residue, which was purified
by chromatography on silica gel. ~he procedure provided
benzhydryl 7~-methoxy-7~-~2-(~ -trichloroethoxycarbonyl-
amino)thiazol-4-ylacetamido)-3-desacetoxycephalosporanate.
~his ester was dissolved in 40 ml of 90 % formic acid and,
'"
- 3 -
~, ., ' ' . .: .
,
,. . -
.
.. ~ .
. ~
:
1064478
under cooling with ice and stirring, 1,30 g, of zinc dust
was added and the reaction was allowed to proceed for 1
hour, ~he reaction mixture was poured in 30 m~ of a satu-
rated aqueous sodium chloride solution and extracted with
ethyl acetate. The ethyl acetate layer was washed with a
saturated aqueous sodium chloride solution and dried over
magnesium sulfate, The ethyl acetate was then distilled
off to obtain crude benzhydryl 7a-methoxy-7~-(2-aminothiazol-
4-ylacetamido)-~-desacetoxycephalosporate, Under cooling
with ice, this crude product was added to a mixture of 3,0
m~, trifluoroacetic acid and 3,0 m~ anisole and the mixture
was stirred for 30 minutes. To the reaction mixture was
added 100 m~ of anhydrous ether and the precipitates were
collected by suction. ~he procedure provided crude 7a-
methoxy-7~-(2-aminothiazol-4-ylacetamido)-3-desacetoxy-
,~
cephalosporanic acid-trifluoroacetate. This product was
dissolved in a 3 % aqueous solution of sodium hydrogen
carbonate and passed through a column of Amberlite XAD-2
(trade name), elution being carried out with water. The
procedure provided 256 mg. of sodium 7a-methoxy-7~-(2-
aminothiazol-4-ylacetamido)-3-desacetoxycephalosporanate.
, , , - ' '
.' xamPle 9
To 50 m~ of dichloromethane was added 4.68 g. of
~'~ benzhydryl 7a-methoxy-7~-aminocephalosporanate and, while
the mixture was cooled at -40C, 2.4 g. of N,~-dimethyl-
aniline was added. Under vigorous stirring, 2.91 g. of 4-
bromo-3-oxobutyryl bromide was added dropwise over a period
of about 10 minutes, during which time the temperature of
,''
- 31 -
.
~" .
.,, , . . , ;, . , , . . , . . : . ,
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`: 1064478
the reaction mixture rose from -40C to -15C. Thereafter,
stirring was continued at -15C to -10C for 30 minutes,
~he reaction mixture was washed with water, dilute hydrochlo-
ric acid, water and saturated aqueous sodium chloride solu-
tion, followed by drying. ~he solvent was then distilled
off to obtain an oily residue. This product, i.e. crude
benzhydryl 7-methoxy-7~-(4-bromo-3-oxobutyrylamido)-
cephalosporanate, was dissolved in 50 m~ of methanol and,
following the addition of 0.91 g. thiourea, the reaction
was conducted at room temperature with stirring for 2 hours
~he methanol was distilled off under reduced pressure and
the residue was washed with ethyl acetate and dissolved by
i .
the addition of 30 m~ water. ~hen, a 5 % aqueous solution
of sodium hydrogen carbonate was added and the substance
that separated out was extracted with ethyl acetate. The
ethyl acetate layer was washed with saturated sodium chlo-
ride solution and dried. The ethyl acetate was then distilled
.
off to obtain 2.43 g. of an oily residue. This product was
identical with the benzhydryl 7a-methoxy-7~-(2-aminothiazol-
4-ylacetamido)-cephalosporanate obtained in Example 1 (3).
Example _10
o 30 m~ of dime~hylacetamide was added 5.24 g. of
benzhydryl 7a-methoxy-7~-amino-3-(1-methyl-lH-tetrazol-5-
ylthiomethyl)-3-cephem-4-carboxylate and, under cooling at
-40C, 2.91 g. of 4-bromo-3-oxobutyryl bromide was added over
a period of about 10 minutes. During this period, the tempe-
rature of the reaction mixture rose from -40C to -15C.
The mixture was further stirred between -15C to -10C for
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-
1064478
. .
an additional hour, after which it was poured in 100 m~
of ice-water. The mixture was adjusted to pH 8 0-8.5 with
sodium hydrogen carbonate and extracted with ethyl acetate.
~he ethyl acetate layer was washed with water, dilute
hydrochloric acid and a saturated aqueous sodium chloride
solution in the order mentioned, followed by drying. ~he
ethyl acetate was then distilled off under reduced pressure
to obtain an oily residue This product, i e benzhydryl
7-methoxy-7~-(4-bromo-3-oxobutyrylamido)-3-(1-methyl-lH-
tetrazol-5-ylthiomethyl)-3-cephem ~I-carboxylate, was
dissolved in 50 m~ of methanol and, following the addition
of 0.91 g. thiourea, the mixture was stirred at room
temperature for 2 hours. ~he methanol was distilled off
under reduced pressure and the residue was washed with
ethyl acetate and dissolved in 30 m~ of water. Following
the addition of a 5 /0 aqueous solution of sodium hydrogen
carbonate, the substance that had separated was extracted
with ethyl acetate. ~he ethyl acetate layer was washed
with water and saturated aqueous sodium chloride solution,
followed by drying. The ethyl acetate was distilled off
under reduced pressure to obtain crude benzhydryl 7a-
methoxy-7~-(2-aminothiazol-4-ylacetamido)-3-(1-methyl-lH-
tetrazol-5-ylthiomethyl)-3-cephem-4-carbonate. Under cooling
with ice and stirring, this product was added to a mixture
of 35 m~ trifluoroacetic acid and 35 m~ anisole and the
reaction was allowed to proceed for 30 minutes Then, follow-
ing the addition of 700 m~ anhydrous ether, the precipitate
was collected by suction and rinsed with ether. The proce-
dure provided crude 7a-methoxy-7~-(2-aminothiazol-4-ylacet-
.
~ - 33 -
.
. . .
- . .
. ~ , . . . . . .
.
1064478
amido)-3-(1-methyl-lH-tetrazol-5-ylthiomethyl)-3-cephem-4-
carboxylic acid-trifluOroacetate~ This product was dissolved
in a 3 % aqueous solution of sodi~m hydrogen carbonate and
the solution was passed through a column of Amberlite XAD-2
(trade mark), elution being carried out with water. ~he
procedure provided 1.25 g. of sodium 7a-methoxy-7~-(2-amino-
thiazol-4-ylacetamido)-3-(1-methyl-lH-tetrazol-5-ylthio-
methyl)-~-cephem-4-carboxylate. This product was identical
with the product obtained in Example 2 (1).
Example 11
(1) ~o a solution of 1.638 g. of 7-methoxy-7~-amino-
cephalosporanic acid benzhydrylester dissolved in 10 m~ of
dichloromethane, was added under ice-cooling 1.5 m~ of
pyridine and then 2.22 g. of 2-(~ -trichloroethoxy-
carbonylamino)-5-chlorothiazol-4-ylacetyl chloride~hydroch
loride and the mixture was stirred for 30 minutes at room
temperature, followed by pouri~g into ice-water. ~he mixture
was extracted with ethyl acetate. ~he ethyl acetate layer
was washed with 0.5N-hydrochloric acid, a 5 % aqueous solu-
tion of sodium hydrrogencarbonate and saturated aqueous
solution of sodium chloride, in this order and dried with
magnesium sulfate, followed by removal of ethyl acetate to
give oily residue. ~he oily residue was purified by chro-
matography on silica gel to obtain 7a-methoxy-7~-~2-(~
trichloroethoxycarbonylamino)-5-chlorothiazol-4-ylacetamido)-
cephalosporanic acid benzhydrylester. ~he nuclear magnetic
resonance spectrum (60 Mc, in CDC~3) showed a singlet
assignable to 3-acetyl protons at 2.00 ppm, a singlet due
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~,
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1064478
to methoxy protons at 3.42 ppm and a singlet due to trichlo-
roethyl protons at 4 86 ppm.
(2) To a solution of 1000 mg o~ the product obtained in
above (1) dissolved in 25 me of 90 /0 formic acid, was added
860 mg. of zinc powder under ice-cooling and stirring,
followed by keeping the mixture under same conditions for
1 hour. ~he reaction mixture was poured into a saturated
aqueous solution of sodium chloride and the mixture was
extracted with ethyl acetate, The ethyl acetate layer was
washed with water and dried with magnesium sulfate and then
subjected to the distillation of ethyl acetate to give 7a-
methoxy-7~-(2-amino-5-chlorothiazol-4-ylacetamido)cephalos-
poranic acid benzhydrylester. ~he nuclear magnetic resonance
spectrum (60 Mc, in CDC~3) showed a singlet due to acetyl
protons at 2.02 ppm, a singlet due to methoxy protons at
3.48 ppm, and a singlet due to 6-hydrogen at 5.18 ppm.
(3) To a mixture of 1.5 me of trifluoroacetic acid and
1.5 me of anisole was added 350 mg. of 7a-methoxy-7~-
(2-amino-5-chlorothiazol-4-ylacetamido)cephalosporanic acid
benzhydrylester, and the resultant mixture was stirred for
20 minutes. The reaction mixture was poured into 50 me of
dry ether to give white precipitates which were collected
by filtration-and washed with ether to give crude trifluo-
roacetic acid salt of 7a-methoxy-7~-(2-amino-5-chlorothiazol-
4-ylacetamido)cephalosporanic acid~ ~he crude salt was
dissolved in 5 me of a 5 % aqueous solution of sodium
hydrogencarbonate and the resultant solution was passed
through a column of Amberlite XAD-2 (trade name), followed
` - 35 -
:
- '
1064478
by elution with water to obtain sodium 7~-methoxy-7~-
(2-amino-5-chlorothiazol-4-ylacetamido)cephalosporanate as
colorless powder. ~he nuclear magnetic resonance spectrum
(100 Mc, in D20) showed a singlet due to acetyl protons
at 2.25 ppm, a singlet due to methylene protons of thiazolyl-
acetyl group at 3.70 ppm, and a singlet due to 6-hydrogen at
5.29 ppm.
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