IL46413A - 7alpha-substituted-7beta-aminocephalosporanic acids and their preparation - Google Patents

Description

46413/2 ni ».r»'io-7a mxoin 7α -Substituted-^ -aminocephalosppranic acids and their preparation MERCK & CO,. INC.

C 44139 46413/2 2 - The present invention consists in new cephalo- sporins wherein the cephenjnucleus, namely a dehydro- thiazine ring with a fused β-lactam contains an amino substituent in the 7- position.

The compounds of the present invention include 3-CH2A-7-amino-7-R1-3-cephem-4-carboxylic acid of the formula and the corresponding 3-oxides, and ealts and esters thereof, wherein A represents hydrogen, hydroxy, halo, azido, cyano, raercapto, alkoxy, aralkoxy, picolinylthio., 1-methyl-l , 2 , 3 , 4- tetrazol-5-yl-thio", alkylthio', aralkylthio, acyloxy,. acylthio, alkylsulfonyloxy, carbamoylox , N-p-sulfonylphenylcarbamoyloxy carbamoylthio or a quaternary ammonium group and R± represents halo, hydroxy, .mercapto, alkoxy, alkylthio, acyloxy, acylthip, aralkoxy or aralkylthio in which the alkyl or aralkyl group 'may be substituted with halo, riitro , hydroxy, carboxy, sulfinyl or sulfonyl groups; loweralkyl, loweralkenyl, loweralkynyl, aralkyl, a cyano, phosphono or alkyl-substituted phosphono group, or a group -of the formula -CX'R" wherein X1 is oxygen or sulfur, and R" is hydrogen, halo, hydroxy,, mercapto, alkyl, alkoxy or alkylthio or R is a nitrogen-oonded group such as These compounds are useful, as inta.Tnediates for the preparation of the corresponding 7-acylamino compounds of formula and. of esters, amides and salts thereof, in which and A, • have -the.-same meaning as_ above and R\ represents an acyl group. ' The compounds of. formula I are/ aluable new antibiotic substancesand form the subject of Patent Specifica ion. No. 3#095, 36989...

The substituent A in formula X above may have any of the meanings listed above. Alternatively, CH2A can be replaced by a formyl group.

Thus, CH2A can be a halomethyl such as chloro-methyl, bromomethyl or fluoromethyl group.

Eepreaeatative of the group -0H«A- that might he mentioned A are methoxymethyl, n-propoxymethyl., methylthiomethyl, ace / methyl, propionyloxymethyl, benzoyloxymethyl, (p-ehloro-benzoyl)oxymethyl, ( -methylbensoyl)ox methyl, plvaloyloxy-methyl, (1-adamantyl)carboxymethyl, butanoyloxymeth 1, carbe-moyloxyme hyl, sulfonylphenylcarbamoyloxyroethyl, methoxy-carbonyloxymethyl, Isobutanoyloxymethyl* carbamoylthiomethyl (ethoxythiocarbonyl) thiomethyl, (n-propox thiocarbonyl) thlo-methyl, methylthipmethyl, N-meth^lpiperazinivuB- -thiocarbonyl-thiomethyl:, ,¥-dimethylpiperazInium-l-thiocarbonylthiometh l, iso hiouroniummethy1, p-tolylsulfpnylthiomethyl, mesyloxymeth l, 1-methy1-1, 2,3,4-tetrazol 1-5-thiomethyl, 46413/2 tosyloxyinethyl, sulfamoyloxymethyl,; When CHg Is a hydroxymethyl, the cephalosporin can also exist as the lactone which is formed by internal esterification with the carboxy group.

Representative of the quaternar ammoniuai groups representing A that might be mentioned are p ridinium, 3-methylpyridinium, 4-methylpyridinium, 3-chlorop idinium, 3-bromppyridinium, 3-iodopy idinium, 4-carbamoyipyridinium 4-(K-hydoxyme hylcarbamo l)p ridinium, 4-(W-earbomethoxy-carbamoy1)pyridinium, 4-(N-cyanocarbamoy ) yridinium, 4- (carboxyme hy1)p ridinium, 4-(hydroxymethyl)p ridinium, 4-(trifluorometh r)pyridinium, quinolinium, picolinium and lutidinium.

She preferred groups representing A are hydrogen halo, azido, cyano, hydroxy, alkoxy, aralkoxy, picolinylfchio , 1-methyl-?l, 2,3,4-tetrazol-5-yl-thi$,mercapto, alkylthlo,aralkyl-thiq, acylthio, acyloxy* iaoitaAa¾PORium , BulJgatooyloxy , quaternary ammonium and alkylsulfonyloxy♦ 5he acyl group can be a lower-alkanoyl group of 2 6 carbon atoms, carbamoyl, or thiocarbamoyl. ¾he substituent i formula X above can have any o the meanings mentioned above* $he oxy.or thio substituen represented by in formula I can be hydroxy o mercapto or a ©ubstituted hydrox or mercapto group such as -XR'^ wherein X is oxygen or sulfur and R' is a hydrocarbyl group, preferably a straight or loweralkyl branched/group of 1-^6 carbo atoms, a straight or branched chain loweralkenyl or loweralkynyl group of 3-6 carbon atoms, or an aralkyl group such as benzyl. These alkyl, alkenyl, alkynyl or aralkyl groups can be substituted with groups such as hydroxy, halo, nitro, carboxy, sulfinyl or sulfonyl 46413/2 When is hydrocarbyl or substituted hydrocarbyl it can be loweralkyl, loweralkenyl, loweralkynyl or aralkyl, which can also be substituted with one or more groups such as halo, hydroxy, nitro, sulfonyl, or carboxy.

R^ in formula X above represents cyano or a group of the general formula -CX'R" wherein X' is oxygen or sulfur, and R" is hydrogen, halo, hydroxy, mercapto, alkyl, alkoxy or alkylthio. Examples of these substituents that might be mentioned -OOO 2 are -CQGH.-CSSH, -CORg,/- COS g, - GSSR2, -CS g, -COHH ^, -CSilSH, -GOK ^ ^, and -CSHR^ wherein Rg represents a straight o branched chain alkyl group of 1-6 carbon atoms and -j and ^ represents hydrogen or Rg ^ in formula X above represents a nitrogen bonded group such as amino( alkyl substituted amino groups, nitro, azido or alkoxycarbonylamino. Ώιβ substltuent ¾ in formula I represents phosphono or a metal or amine salt thereof, or an alk l substituted phosphono group.

In accordanc with the nomenclature of cephalosporin compounds used in the art, the compound obtained by hydrolysis of cephalosporin 0, which can be represented by the structural formula 1 is called 7-aminocephalosporanic acid or 7-ACA. 2 The term "decephalosporanic acid" used herein to • 3 describe certain products, pursuant to its usage in this ari , 4 represents the basic heterocyclic nucleus having the struc- 5 tural formula · Thus, a. compound of the formula 7 . is called 3-methyl-7-aminodecephalosporanic acid using this 8 system of nomenclature. 9 The cephalosporin compounds with which this 10 invention is concerned are also conveniently designated as; 1 "cepham" compounds containing the basic fused-ring. beta-. , ' 12 lactam thiazine structure 13 which is known as cepham. Thus, the cephalosporin compounds 14 aro called "cephem" referring to the basic structure with a 15 single olefin band. For example, in this system of nomen- 16 clature cephalosporin C having the structural formula is named 7- (5'-anin'oadipamido) -3-acetoxymethyi-3-cephem-4-carboxylic acid.

. The new intermediates of this invention can be prepared by the processes which can be depicted as follows (IV) V where and A are as defined above.

In the foregoing flowsheet the . starting compound is a derivative of 7-aminocephalosporanic acid (II) , herein-after also called 7-ACA, wherein the carboxy group is preferably blocked, for example by forming a suitable ester. Thus, 7-ACA or analogs thereof having a different substituent at 3 can be esterified in accordance with methods well known in this art to obtain, for example, the esters wherein Rg represents an alkyl or substituted" alkyl group such as methyl, t-butyl , pivaloyloxymethyl , acetoxymethyl and tho like, a haloalkyl such as trichloroethyl , an alkonyl group such as allyl, an alkynyl group such as propargyl, an 1 aralky'l group such as benzyl , benzhydryl, o-nitrobenzyl , 2 3,5-dinitrobenzyl or p-methoxybenzyl , an aryl group such as 3 phenacyl, an organocmetallic group for example a silyl group 4 such as trimethylsilyl, or a stajinyl group such as tributyl-i I 5 tin, phenacyl or trichloroethoxycarbonyl. The ester (II) is 6 converted to the corresponding 7-diazocephalosporanic acid 7 ester or 3-CH2A-7-diazocephalosporanic acid ester (III) by 8 reaction with nitrite. The 7-diazo ester (III) is con- 9 verted by reaction with a pseudo halogen compound, or compounds, 10 or a compound which acts as a pseudo halogen, to form 11 intermediate product (IV) wherein X represents halogen 12 from the group consisting of bromine, chlorine and iodine 13 or another leaving group, and Y is' a nitrogenous substituent 14 or R^. Intermediate compound (IV) . is then converted to . compound (V) wherein R has the same meaning as in formula X, and Z represents a nitrogenous group which is readily convertible to amino. Also, the substituent at 3 21 position 3 of the Δ -cepham nucleus can be converted to the 22 other substituents of the formula -CH2A in accordance with 23 methods known, in this art and those described herein. The 24 processes for carrying out the various steps of the fore- 25 going flowsheet will be more readily understood from the 26 detailed descriptions of methods which can be used to carry 27 out these processes which follows.

The starting material in the foregoing process can be 7-ACA or a S-CI^A 7-aminddecephalosporanic acid which is first reacted to block or protect the carboxy group. One such protecting group is tri-loweralkylsilyl , which is employed by treating the cephalosporanic acid starting material, for example 3-carbamoyloxymethyl-7-aminodecephalo- sporanic acid, with hexamethyldisilazane to afford the corresponding trimethylsilyl 3-carbamoyloxymethyl-7- aminodecephalosporanate. Examples. of particularly suitable 3-CH2A 7-aminodecephalosporanic acids that might be mentioned are those wherein A represents hydrogen, hydroxy, azido, halo, a tertiary amine, isothiouronium, a loweralkoxy or l weralkyl-thio group, an acyloxy or acylthio group, or a 5 or 6 membered heterocyclic oxy or heterocyclic thio substituen having one or more 0, S or N heteroatoms in the ring.' When A is halo it/ be fluoro, chloro or bromo. When A represents a loweralkoxy or loweralkylthio group it may be a group such as methoxy, methylthio, tertiary butyloxy, tertiary, butylthio, and the · like. When A represents an acyloxy or acylthio group it may be a group such as acetoxy, benzoyloxy, cinnamoyloxy, p- sulfocinnamoyloxy, isobutyryloxy , pivaloyloxy, adamantoyloxy , carbamoyloxy , N-p-sulfophenylcarbamoyloxy or mesyloxy.

When A represents a tertiary amine it can be pyridinium quinolinium, picolinium and lutidinium.

The 3-methyl-7-aminodecephalosporanates are synthesized by treating the appropriate 3-methyl-7- aminodecephalosporanic acid with an acylating agent such as trichloroethoxycarbonyl halide or t-butoxychloroformate to afford 3-methyl-7|3-trichloroethoxycarboxamidodecephalosporanic acid or 3-benzoylthiomethyl-7 -t-butoxycarboxamidodecephalo-' sporanic acid. The 3-methyl-70-trichloroethoxycarboxamido- decephalosporanic acid intermediate thus obtained may then be treated with p-methoxybenzyl bromide or o-nitrobenzyl bromide to afford p-methoxybenzyl 3-methyl-73-trichlorp- ethoxycarboxamidodecephalosporanate or o-nitrobenzyl 3-methyl- 70-trichloroethoxycarboxamidodecephalosporanate , and. the compound thus obtained is then treated with zinc in an acid solution to yield the desired p-methoxybenzyl 3-methyl-7- a inodecephalosporanate or o-nitrobenzyl 37methyl-7-amino- decephalosporanate compound.

. The diazotization of the 7-amino ester is carried out in accordance with processes well known in this art.

Thus, it is conveniently effected in aqueous or aqueous- organic solvent medium, for example by reaction with sodium nitrite in the presence of an acid or by reaction with an organic nitrite. Organic solvents suitable for carrying out this reacton are those which do not contain an active hydrogen. Examples of such solvents that might be mentioned are methylene chloride, ether, benzene, toluene, chloroform, and the like. The reaction is preferably carried1 out at temperatures between about 0 and 50eC. ; usually.it is most conveniently effected at room temperature. The isolation of the desired diazo compound is* readily accomplished in accordance with methods known in the art.

Thus, in accordance with one specific embodiment of this invention, the new cephalosporin intermediates of formula X are obtained by the following processes: (VIII) (X) whore the substituents are as defined above. , In the above process the 7-diazocephalosporanic acid ester (III) is reacted with a halo azido from the group consisting of bromine, chlorine or iodine azido, preferably in the presence of a tertiary amine azide, to produce the intermediate 7-halo-7-azidocephalosporanic acid ester (VII) which on reaction with a suitable nucleophilic reagent is converted to the desired 7-R1-7-azidocephalosporanic acid ' ester (VIII)·.. The 7-R-L-7~azidocepb.alosporanic acid ester (VIII) is reduced to the 7-^-7-aminocephalosporanic acid . ' ester (IX). The ester group of. compound (IX) can be cleaved to obtain the free acid (X). This latter can be acylated to form the desired substituted cephalosporin or a salt thereof of formula I above. The step of ———————— cleaving the blocking group is readily effected in' accordance with methods known in this art. For example, an aralkyl group such as the benzyl ester is removed by reduc- tion, a silyl ester can be removed by hydrolysis to form the free acid or a salt thereof and a benzhydryl group is readily cleaved by reaction with trifluoroacetic acid in the presence of anisole. In this process other esters which are readily cleaved to form the free acid such as trichloroethyl , phthalimidomethyl , succinimidomethyl , p-methoxybenzyl , o- nitrobenzyl, phenacyl and t-butyl and the like can be used. ,..Also, as is discussed above, the 3-subst'ituent on the Δ - cepha nucleus can be varied following the procedures known in this art to obtain the substituted cephalosporins of formula I. In this manner, phenacyl 3-benzoylthiomethyl-7- aminodecephalosporanate (obtained by treating 3-benzoylthio- methyl-73-t-butoxycarboxamidodecephalosporanic acid with a- bromoacetophenone) can be prepared via the reaction of phenacyl 3-benzoylthiomethyl-7 -t-butoxycarboxamidodQcephalo- sporanate with trifluoroacetic acid. / - 18 - The step of producing the halo azide intermediate is carried out by reacting the diazo compound with a halo azide at a temperature between about 0 and 50°C. for suffi-cient time to complete the formation of the desired compound. 1 The reaction is preferably carried out in a suitable organic solvent medium which is inert to the reactants. Various solvents which do not contain an active hydrogen such as methylene chloride, chloroform, benzene, toluene, ether and the like, or mixtures thereof provide suitable mediums for carrying out the reaction. , Generally, it is preferred to effect the reaction in the presence of a second azide such as lithium azide or a tertiary ammonium azide, for example triethylammonium azide, since under these conditions the formation of the undesired 7-dibromo compound is avoided. The halo azide is used in an amount in slight excess of stoichemetric requirements. The amount of second azide is not critical and it is generally desirable to use an excess in order to obtain maximum yields of the desired halo azido compound under optimum conditions. After completion of the formation of the halo azide the product is recovered and can be purified further, for example by chromatography, in accordance with processes well known in this art.

The next step of the process comprising the replacement of the halo substituent by a nucleophilio group is effected by reacting the halo azide with a sub- ' stance capable of furnishing a group to replace the halo.

This reaction is preferably carried out in the presence of a suitable non-reactant solvent such as methylene chloride, chloroform, benzene, toluene, ether, petroleum ether and the like; again it is desirable to avoid using . any solvents containing an active hydrogen. Thus, in accordance with a specific embodiment of this invention, the nucleophilic displacement reagent can be an alcohol such as methanol, ethanol, phenol, benzyl alcohol, a substituted alcohol such as 2-bromoethanol , 2-methoxyethanol , glycol amide, an ester of glycolic acid and the like which results in the displacement of the halo group and the introduction of a methoxy, ethoxy, phenoxy, benzyloxy, 2- bromoethoxy, methoxy, 2-methoxyethoxy, carbonylmethoxy or esterified carbonylmethoxy substituent, respectively. The reaction is preferably carried out in the presence of a, heavy metal cation such as a silver salt. When the reaction is carried out by reacting a salt of an organic acid, preferably a heavy metal salt such as a silver salt, the corresponding 7 acyloxy compound is obtained. For example, reaction of the halo azide with silver acetate-, silver benzoate, silver t- butylacetate , silver phenylacetate the corresponding 7- acetoxy, 7-benzoyloxy , .7-t-butylacetoxy and the 7-phenyl- acetoxy intermediate compound is obtained. The acyl groups of these various acyloxy compounds can then be cleaved to obtain the corresponding 7-hydroxy compound. ( Γ -Alternatively, in this process , of preparing the 7-acyloxy compounds the reaction can be ',· ' carried out by using a salt of the appropriate acid and i carrying out the reaction in. the presence of a heavy metal salt such as silver oxide or silver 'tetrafluoroborate. .-By reacting the appropriate 7-hydroxy compound with amino- ·' carbonyl chloride, methyl chlorocarbonate and aminosulfonyl chloride, there are obtained respectively the 7-aminocarbonyl-. oxy, 7-methoxycarbonyloxy and 7-aminosulfonyloxy derivatives. 1 : . - , . ,. .

In the next step of the above-described process the 7-azido-7-R1 compound is then reduced to afford, the ·, ,. , . " corresponding 7-amino-7-R1 compound. Various methods of · ■ carrying out this reduction can be- employed, but it is generally preferred to carry out the reduction of the azido to the amino group by catalytic hydrogenation employing a noble metal catalyst such as platinum, palladium or oxides' ' .· thereof. These processes are carried out in accordance with procedures well known in this art. The 7-amino compound oan be reacted with suitable acylating agents using procedures well known in this art o obtain 7-acylamido compounds of formula I. Thus, in the above- ■ ■ , described process where the substituenfc Us a halo group, for example chlorine, bromine or iodine, the 7-azido-7- hal'o compound can be reduced to the corresponding amine compound and the latter compound can then be acylated to obtain the 7-acylamino-7-halo product. Alternatively, as discussed above, the reduction and acylation steps can be combined to produce the 7-acylamido compound without separating and acylating the 7-acylamido intermediate. 7-Amino-7-azidocephalosporanatesare obtained by conversion of a 7-halo-7-azidocephalosporanate into the corresponding 7,7-diazidocephalpsporanate by treatment with an alkali metal azide and this intermediate is then subjected to reduction by hydrogenation in the presence of a suitable catalyst as, for example, a palladium-on-charcoal catalyst.

The process is illustrated by the following reactions.

Alternatively, in accordance with a further embodiment of this invention, the 7-aminocephalosporins are also obtained using a benzhydryl ester of the 7- azido-7-halo compound of formula VII as the starting material. This compound is reacted with t-butyl carbamate to produce the corresponding 7-t-butylcarbonylamino - compound. Reduction of this intermediate product with hydrogen in the presence of platinum oxide affords the. 7-amino-7-t-butylcarbamoylaminpbenzhydryl ester. The latter compound is then acylated to produce the benzhydryl- 7-acylamido-7-t-butylcarbamoylamino compound which on treatment with trifluoroacetic aoid in the presence of anisole affords the 7-aminocephalosporin.

The 7-amirib-7-phosphono compounds and the 7.-amino- 7-phosphinyl products of this invention and their corres-- ponding salt and ester' derivatives are obtained by treating . a 7-azido-7-halocephalosporanate compound with an appropriate phosphite, phosphonamidic acid or diamidophosphorous acid' in the presence of a metal salt, i.e. a silver salt such as silver oxide or silver tetrafluoroborate and the like.

The 7-azido-7-phosphono (or 7-phosphinyl) compound thus obtained is then reduced to. the corresponding 7-amino-7- phosphono (or 7-phosphinyl) cephalosporanate , .

When the halo azide compound is reacted with carbon dioxide or carbon disulfide in the presence of phenyllithium, the corresponding 7-azido-7-carboxy or 7-azido-7-thiocarboxy compound is obtained. These carboxy or thiocarboxy compounds can be converted to the corresponding haloformyl compound by reaction with halogenating agents pursuant to processes well known in this art. For example, the 7-carboxy-7-azido compound by reaction with thienyl chloride is converted to the 7-chloroformyl-7-azido compound which can be reduced to the 7-amino-7-chloroformyl compound. Further, the 7-haloformyl compound on reaction with an alcohol such as methanol, phenol or benzyl alcohol is converted to the corresponding 7-methoxycarbonyl, 7-phenoxycarbonyl, or 7-benzyloxycarbonyl compound. The 7-formyl compounds are prepared by treating the 7-nydroxymeth l substituted products with phosphoric acid at pH 2-3 to obtain the 7-hydroxy compound and then oxidising these latter produots with chromium trioxide pyridine complex. / Sodium 7a-formyl-7-(aiDiino)cephalosporanate may be made in this manner from the, 7a-hydroxymeth l compound. ,t The new cephalosporanic and decephalosporanic acids wherein is a hydrocarbyl group are prepared by reactions shown in the following flowsheet: ' (XIX) where D is a hydrocarbyl and Ά is as defined above.

In accordance with the foregoing flowsheet, the dlazooephalosporin compound is reacted with a trlhydrocarbyl boron compound at low temperatures, i.e. -50eC. to -100°C. , for sufficient time to produce the 7-dihydrocarbylboron-7* hydrocarbon intermediate (XVII) . Upon reacting this intermediate with a halogen azide such as bromine azide at room temperature, the 7-hydrocarbyl-7-azido compound (XVIII) is obtained. The latter compound is then reduced catalytically , to produce the desired 7-hydrocarbyl-7-amino-cephalosporanic or decephalosporanio acid (XIX) or a salt thereof.

In carrying out the first step of this procedure, the hydrocarbyl group of the boron compound can be a lower- alkyl group of 1 to 6 carbon atoms, a loweralkenyl group of 2 to 6 carbon atoms, a loweralkynyl group of 2 to 6 carbon atoms, an aralkyl group such as benzyl, or an aryl group such as phenyl. Thus, using these tri-substituted boron compounds, the corresponding 7-alkyl, alkenyl, alkynyl, aralkyl or arylcephalosporanic acid compounds are obtained.

In -this way the following compounds are made via - the benzhydryl ester: sodium 7-methyl-7-, amino— '"' ' cephalosporanate, sodium 7-ethynyl-7-jamino———}" < >■ »> ■ '. ■ cephalosporanate , 7a-phenyl-7-amino-cepha_losporani acicl f - ' 7 By treating benzhydryl 7-diazocephalosporanate with CPjl-triethylammonium azide in UV light benzhydryl 7-azido-7-trifluoromethyl-cephalosporanat'e is obtained which can further be processed into the corresponding 7-amino-7-trifluoromethyl compound.

Thus in accordance with a, specific embodiment of ' this invention, new cephalosporins having,a 7-carboxy or substituted carboxy substituent are obtained by the following prooe.sses: (XXII) Thus, pursuant to one of the foregoing processes, the intermediate product (IV) obtained as described above is reacted with a hydrocarbyl lithium compound of the formula R1QLi where represents a hydrocarbyl group suc as loweralkyl or alryl, for example n-butyl lithium, to form the 7-lithium compound (XX) which is reacted with- carbon 1 dioxide to produce the 7a-carboxy compound (XXI). This 2 intermediate is converted to the carboxy 7-cephalosporin 3 (XXII) using methods shown above, or the carboxy substituent 4 can be converted to a carboxylic acid derivative such as 5 an~ ester, an amide, a hydrazide, an azide or a hydroxamip 6 acid using procedures known in the art. Alternatively, 7 when the 7-lithium compound is reacted with carbon disulfide 8 in place of carbon dioxide, the corresponding 7-dithio- 9 carboxy (-CSSH) compound is obtained. f Ί 0 Sodium 7-carbomethoxy-7-' amino-1 cephalosporanate is prepared ih this way via benzhydryl 2 7-carboxy (and 7-chloroformyl) cephalosporanate. The com-3 pound may be converted to the corresponding 3-pyridinium-4 methyl compound with potassium iodide in pyridine. Other 5 products obtainable by this process are sodium 7-hydrazino-6 carboxy1-7-amino- -^ cephalosporanate and sodium 7 7-thiocarboxylmethyl-7- amino———-—-— cephalosporanate..! . 8 The 7-cyanocephalosporins are prepared by reacting 9 the 7-halo-7-azido intermediate of formula VII above with • · 0' tetrabutylammonium cyanide to obtain the 7-cyano-7-azido 1 compound. This intermediate product is then reduced to the *2 7-cyano-7-amino compound, ; In this way disodium 7a-cyano-7-amino-cephalosporanate is prepared from benzhydryl 7-bromo-7-azidocephalosporanate.

The 7-formyl cephalosporins are prepared by converting a 7-hydroxymethyl-7-acylamidocephalosporanic * '· ' ".· ··· I ' acid or a corresponding 3-CH2A decephalosporanic acid with an oxidizing agent such as pyridine-chromium trioxide to produce the 7-formyl compound. This latter cephalosporin ■ ■" compound is converted to the corresponding 7-carboxy roduct b mild oxidizin a ents such as ar entic oxide. ■ .

The 7-halo-substituted cephalosporins of this invention are prepared by subjecting the 7-halo-7-azido intermediates of formula VII above to reduction to afford the corresponding 7-halo-7-amino compound, In another embodiment of this invention, the novel be represents hydrocarbyloxy or hydrocarbylthio .

In accordance with the above flowsheet, the starting compound, an ester of a 7-diazo compound defined as in III above, is reacted with a hypohalite of an alcohol or a thiol, or with an alcohol in the presence of a positive halogen such as a N-halo-amide, for example, N-bromoacet- amide, N-bromosuccinimide, N-bromophthalimide and the like, that react as though they were the corresponding hypohalito. a The resultant 7-halo-7-hydrocarbyloxy or hydrocarbylthio ester (XXIII) is frequently. a mixture of epimers at 7, · which are readily separable by chromatography. However, when only one epimer is obtained, it may be equilabrated to a mixture of epimers by treatment with an organic halide in a polar solvent. A lithium salt of the appro- priate halide in dimethylformamide is particularly useful for epimerizing these intermediates. The 7-halo-7- "hydrocarbyloxy or hydrocarbylthio product can then be j , reacted with an azide, such as lithium azide, to form the 7-hydrocarbyloxy or hydrocarbylthio-7-azidocephalo- Ί sporanate ester (XXIV) . This latter compound can then { be reduced either with hydrogen or an inorganic reducing agent to form the intermediate 7-hydrocarbyloxy or hydro- carbylthio-7-amino ester (XXV).

The various processes described above can result in the production of a particular epimer at 7, or in a mixture of epimers at 7; i.e., a 7a-halo-7fJ-R1 or a 73-halo-7a-R1 compound. When a mixture of epimers is obtained these can be readily separated in accordance with methods, j such as chromatography, which are well known in;..this art. In some cases, when only one epimer is obtained it can be ! equilabrated to produce a mixture of epimers by procedures known in the art. v ϊ An alternative route for the preparation of the 7-R -7-amino compounds of formula IX above comprises react ing a 7-amino compound of formula II above with an aromatic aldehyde to form an imino adduct, treating this i ino adduct with a defined reagent yielding a 7-R-_ Schiff's base adduct and then regenerating the amino moiety, f, ' ' \ . . . . vMore specifically, this alternative route can be used to prepare compounds having the following formula: wherein A and Rg are as previously defined, and R^ is lower alkyl, lower alkoxy, lower alkylthio, lower alkanoyl, halo, lower, haloalkyl, lower alkanoyloxy, (a-hydroxy) lower alkyl, allyl, benzyl, cyano, carbamoyl, carbolower-alkoxy, loweralkylsulfonyloxy or phosphor*) · The starting material is the 7-NH2 compound of formula II above which is reacted with an aromatic aldehyde, preferably one having at least one o- or p- electronegative substituent, selected from the group consisting of nitro, methyl sulfonyl, cyano, carboxyl, derivatives, and the like. The preferred reactant is p-nitrobcnzaldehyde. 1 The starting material and the aromatic aldehyde Ί ' 2 are mixed together in approximately equimolar amounts in 3 an inert solvent. Suitable solvents are dioxane, aceto- 4 nitrile, dimethylformamide, dimethylsulfoxide benzene, 5 toluene, and the like. The aldehyde can be employed in 6 a molecular excess if desired. The reaction proceeds 7 readily at temperatures ranging from ambient to reflux 8 temperature of the solvent. Since this condensation is 9 an equilibrium reaction and since water is one of the 0 products of the reaction, water is removed from active 1 participation in further reactions by any of a number 2 of usual methods, including azeotropic distillation, 3 molecular sieves, or borate esters. The particular 4 method is dependent upon the exact parameters of the 5 reaction. The reaction is terminated by evaporation of the 6 solvent. The imino derivative is then recovered and used 7 in the next step. 8 The latter involves the substitution of the R 9 group at the carbon atom adjacent to the imino nitrogen. 0 This reaction takes place in the presence of an inert 1 solvent, such as those listed above, and in the additional 2 presence of an organic or inorganic base. It is pre- 3 ferred to use organic bases, such as tertiary amines or, 4 pyridine. A specific tertiary amine which is preferred 5 is diisopropylethylamine, although any tertiary lower 6 alkylamine can be used. Inorganic bases, such as NaH, 7 NaOH, KOH, carbonate, or bicarbonate salts, etc. can also 8 be employed. For instance, the reaction can be conducted 9 in "soft glass" which contains enough soluble inorganic 0 base to catalyze the reaction. '"■'·■ !· . .. \ J* - 33 - The specific reactant which is employed in the reaction with the imino compound to result in the chosen R^ group obviously depends on the R^ group, desired.

The following is of value in defining each reactant in terms of the final R^ group.

,: Reactiarit , Rl 1. lower aXLkyl sulfate or halide loweralkyl 2. loweralkanoyl halide loweralkanoyl 3. loweralkyl peroxide loweralkoxy 4 loweralkyl disulfide loweralkylthio 5 tertbutylhypohalite or perhalo ethylhypohalite halo 6 halolowerrlkane haloloweralkyl 7 loweralkanoyl peroxide lQweralkanoyloxy 8. formaldehyde or loweralkyl- aldehyde (a-hydroxy) loweralkyl 9· reactive loweralkyl ketone (a-hydroxy) branched- loweralkyl 01 ally! halide allyl 1. benzyl halide benzyl 2. cyanogen bromide cyano loweralkylhalo formate carboloweralkoxy loweralkylsulfonyl halide loweralkylsulfo phosphorus oxychloride phospho carbondioxide carboxy " (α-Hydroxy) loweralkyl" is used to mean a grou of the formula wherein R is hydrogen or alkyl having 1-6 carbon atoms. , "Reactive loweralkyl ketone" is used' to. mean a ketone of the formula Q R'-C-R" wherein one of R' or R" is a halogenated loweralkyl group, the halogen-substituted carbon being adjacent to the carbonyl function; or one of R' or R" is an alkyl carbonyl group. The carbonyl being adjacent to the carbonyl of the ketone; the other of R1 or R" is loweralkyl. Thus, to illustrate, one type of "reactive loweralkyl ketone" is : X 0 X'-C-C-R" X" wherein X is halo, X" is halo or hydrogen, and X' is halo, hydrogen, or loweralkyl; and R" is loweralkyl.

The other type is 0 0 R'-C-C-R" R" is hydrogen or loweralkyl, and wherein R" is loweralkyl, haloloweralkyl , loweralkoxy, or lowerhaloalkoxy . " (a-HydroxyJbranchedloweralkyl" means a group of the formula X'- lC-X" or ΪC-OH ■ ·.

The 7-R^-7-aminocephalosporanic acid and 7-R^-7 aminodecephalosporanic acid esters of formula IX above prepared in this way can then be converted to the cephalo sporin compounds of formula I.

"Reactive ethylene derivative" is used to mean art ethylenically unsaturated compound which is activated by the presence of one or more strong electron withdraw-ing groups. For example, compounds of the formula .

II , CH2=CHY where Y is -00, -N02, -CN, -C-0-CH3, CF3, and H the like are included.

The term "( β-substituted) ethyl" is employed^to mean the following group » .. .' I -CH2-CH2Y ! wherein Y is the same as defined as. above.

Following the reaction between the imino compound and the reactant to form, the novel 7-R' compounds, the imino moiety is regenerated to amino.

This regeneration is effected by aminolysis or hydrazinolysis , in the presence of a catalytic amount of acid. Preferably, aniline hydrochloride .;is employed which serves both as a source of amine and acid. When hydrazine or hydrazine derivatives such as phenylhydra-zine, 2 , 4-dinitrophenylhydrazine , and the like are used, acid is added. Other hydrazines or amines can be employed. Preferred media are the loweralkanols , such as methanol, ethanol, and the like. The usual acids or! bases can be employed. For instance, hydrochloric p-toluene sulfonic acid o aniline can be used. The only limitation is that no undesired hydrolysis or ring damage occur..

The 7-R^-7-aminocephalosporanic acid and 7-R^-7-aminodecephalosporanic acid esters of formula IX above prepared in this way can then be converted to the cephalo-sporin compounds 0f formula I The following examples are given for the purpose of illustration and not by way of limitation.

E AMPLE^l A. Benzhy_drv_l _7-arninoc o goranatΘ To a slurry of 6.8 g. (.025 mole) of 7-amino- cephalosporanic acid in 300 ml. of peroxide-free dioxane at room temperature is added with stirring 4.3 g. (.022 mole) of p-toluenesulfonic acid monohydrate. The clear solution is concentrated in vacuo and flushed twice with dioxane.

The residue is dissolved in 300 ml. of dioxane at room temperature, and a' solution of 10 g. (.05 mole) of diphenyldiazoraethane in 25 ml. of dioxane is added dropwise over 15 minutes. The wine-colored solution is stirred for an additional 30 minutes, then 25 ml. MEOH is added to destroy the excess 2CN2 . The mixture is , concentrated in vacuo and the residue partitioned between 200 cc. CH2C12 and 200 ml. water containing 10 g. K2HP04 (pH 8.5) . The organic phase is washed with water, dried over and concentrated in vacuo to yield an oil.

The oil is stirred with 100 ml. of ether for 1 hour. The precipitate is filtered, washed with ether and dried to constant weight 4.7 g. (43%). m.p. = 126-128 eC. Analysis calculated: C, 63.0; H, 5.01; N, 6.37.

Found: C, 62.7; H, 5.18; N, 5.18. IR in CHClj is 5.6μ (β-lactam C»0) and 5.8μ (ester 0=0) . NMR in CDC13 is 0 1.85 ( " (singlet, NH2) ; (doublet, CH2S); 4.8 (f(singlet, CH20AC) ; 4.7 < " (doublet , C,H) ; 4.9f(doublet, C-H) ; 6.98 ; and 7Λ (singlet, phenyl) . By following this procedure above there is also prepared benzyl 3-picolinoylthiomethyl-7-diazo cephalosporanrte, using the appropriate reagents.

B. ¾enzhyjdry_l_7-diaz^ To a stirring mixture of 1.6 g. of NaNC^ , 30 ml. of water and 40 ml. of CH2C12 at oeC. is added 880 mg. (.002 mole) of benzhydryl 7-aminocephalosporanate followed by the addition of a solution of 760 mg. (.004 mole) of p-toluenesulfonic acid in 5 ml. water over a few minutes.

The mixture is stirred at o'C.for 20 minutes, then the organic phase is cut away, washed with 1.x 10 cc. ice water, dried over Na2S04 at o°C, filtered and concentrated in vacuo at room temperature to yield 900 mg. of. a glass. of benzhydryl 7-diazocephalosporanate. IR is 4.8μ (strong N=N) , 5,6μ (fc-lactam O.O) and 5.8μ (ester C-0) . NMR in CDC!, is 2.0 (singlet, CH3C); 3.4 cf[doublet, CHjS) ; 4.8 ^/" (singlet, CH OAC) ; 5.6 (sin let C H) 6.98 . 14346" The following pompounds are also prepared in this manner from appropriate starting materials: trimethylsilyl 3-carbmoyloxymethyl-7-diazodecephalosporanate, benzhydryl 3-pyridiniummethyl-7-diazodecephalosporanate, benzhydryl 3-N- (2-chloroethyl) carbamoyloxymethyl-7-diazodecephalosporanate, and p-methoxybenzyl-7-diazocephalosporanate. i C. ½nzhy_dry_l_7_ bromo-7-azid^ To a solution of 900,mg. of benzhydryl 7-diazo-cephaiosporanate in 20 ml. CH2C12 and 10 ml. CH3N02 at 0- 10eC. is added all at once the triethylammonium azide + - solution (E 3NHN3) (prepared below) followed by the Br ^ solution, (prepared below) then 50 ml. of water is added followed by the addition of solid NaHC03 to pH 8.

The organic layer is separated and extracted with 2 x 2Ό ml. water, dried over a2S04 and concentrated in acuo to yield 900 mg. (83%) of benzhydryl 7-bromo-7-azido-cephaiosporanate.

The NMR fits the structure. Thin layer chroma- · tography on silica gel with CHC13 shows a major spot at- ■ Rf 0.2. Chromatography of 900 mg. crude product on 25 g. silica gel with CHC13 gives 400 mg. (39%) single spot material as an oil.

IR in CHC13 is 4.72μ (N3) , 5.56μ (β-lactam C=0_ and 5.75μ (ester OO) . NMR in CDC13 is 2.0^" (singlet, 0 CH3C); 3.38^(CH2S) ; 4.7 (f(singlet CHjO) ; 4.9< * (CgH) ; phenyl) . 14346 Preparation of BrN3 Solution To 8 ml. of CH2C12 at 0eC. is added 2.66 g. (.04 mole) of aN^ followed by 0.65 g. (.0042 mble) of bromine. To this stirring mixture at 0°C. is added drop- wise 2 ml. of concentrated hydrochloric acid. The mixture is stirred for 3 hours at 0°C.

The organic layer is decanted and the aqueous layer extracted with 1 x 5 ml. of CH2C12. The combined organic phase is stored at -10°.C.

+ - Preparation of Et^Nj-N^ Solution To a slurry of 1.5 g. of a ^ in 5 ml. water and 10 ml. CH2C12 at ~10°C. is added dropwise at -10eC. to 0°C. 4 ml. of 50% l^SO^. The organic phase is poured off the aqueous paste, and the aqueous extract washed with 1 x 5 cc. CK2C12. The combined organic phase is dried 1 over CaCl2. The decanted H 3 solution is brought to pH 7 with Etj and the triethylammonium azide thus obtained is stored at -10°C.

In this manner the following products are also prepared: o-nitrobenzyl 3-methyl-7-azido-7-bromodecephalospor anate, 3~carbamoyloxymethyl-7-azido-7-bromodecephalosporanic acid, phenacyl 3-benzoylthiomethyl-7-azido-7-bromodecephalos- poranate, p-methoxybenzyl 3-methyl-7-azido-7-bromodecephalo- sporanate, benzyl 3-picolinoylthiomethyl-7-acidb-7-bromo- decephalosporanate, benzhydryl 3-pyridihiummethyl-7~azido- 7-bromodecephalsoporanate, p-methoxybenzyl 3-methyl-7-azido- 7-chlorodecephalosporanate, benzyl 7-azido-7-chlorocephalo- . sporanate, benzhydryl 7-azido-7-chlorocephalosporanate, : 143 6 1 7-azido-7-chlorodecephalosporanate, benzhydryl 3-pyridinium- 2 methyl-7-azido-7-chlorodecephalosporanate, benzhydryl 3-N- 3 (2-chloroethyl) carbamoyloxymethyl-7-azido-7-chlorodecjephalo- 4 sporanate, t-butyl-7-azido-7-chlorocephalsporanate, benzhydryl 5 3-n-amyl xymethyl-7-azido-7-chlorodecephalsporanate and I 6 p-methoxybenzyl-7-azido-7-bromocephalosporanate.. 8 To a solution of 400 mg. (.00072 mole) of 9 benzhydryl 7-bromo-7-azidocephalosporanate in 30 ml. methanol 10 is added 150 mg. (.0008 mole) of AgBF^. The mixture is 11 stirred in the dark for 2 1/2 hours. 12 The mixture is concentrated in vacuo and the 13 . residue taken up in 50 ml. of CH2C12 filtered. The filtrate .14 is extracted twice with saturated NaHC03 solution, twice 15 ' with wa'ter, dried over anhydrous MgS04 and concentrated .. 16 in vacuo to yield 300 mg. (83%) of crystals, m.p. = '" 17 145-148 °C. . '," ". 18 IR in CHC13 is 4.72μ (N3 band), 5.6μ (β-lactam), 0 19 and 5.75u (ester C=0) . NMR is 2.Q(f(singlet, CH3C) ; 20"' 3.4 f (CH2S); 3.6, " (singlet, OCH3) ; 4.88 E. Benzhydryl _7-me^ ' 1.0 g. of benzhydryl 7-azido-7-methoxycephalo-sporanate is dissolved in 100 ml. of dioxane. 1.0 g. of platinum oxide is added and the reaction mixture stirred under hydrogen at atmospheric pressure for 1 hour. Another 1.0 g. quantity of platinum oxide is added and the reac-tion mixture is again placed under hydrogen and stirred for 3 hours until the azide is completely reacted as determined by infrared analysis of aliquots. The solvent is removed under reduced pressure and the residue taken up in 50 ml. of chloroform and filtered through silica gel G in chloroform in a 60 ml. sintered glass funnel. The material is eluted with chloroform until 200 ml. of chloro-form has been collected. The chloroform is removed under reduced pressure affording 0.632 g. of benzhydryl 7-methoxy-7-aminocephalosporanate. The starting compound is prepared using the procedures described in Example 1 starting with the benzhydryl ester of 7-aminocephalosporanic acid. in this manner the following compounds are prepared: p-methoxybenzyl 7-amino-7- (2-methoxyethoxy) cephalosporanate, benzhydryl 7-amino-7-benzyloxycephalosporanate, benzhydryl 7-amino-7- (L-2-benzhydryloxycarbonyl-2-t-butpxycarbonylamino-ethoxy) cephalosporanate, benzhydryl 7-amino-7- (carbamoyl-methoxy) cephalosporanate, benzhydryl 7-amino-7-acetoxycephalo-sporanate, and benzhydryl 7-amino-7-phenoxycephalosporanate.

■ "' * E AMPLE^ 500 mg. of platinum oxide is added to a solution.

I.", of 500 mg. (1.07 mm.) of benzhydryl 7-azido-7-methoxy-oephalosporanate in 50 ml. of p-dioxane in a 250 ml. round bottom flask. The reaction vessel is placed under hydrogen at room temperature and atmospheric pressure with vigorous, magnetic stirring. After 1 hour, 500 mg. of fresh platinum oxide is added and the reaction continued under the same conditions for an additional 3 hours. The dioxane is removed in vacuo at room temperature and the residue taken up in 5 ml. of chloroform. The catalyst is removed by passing the mixture through 15 g. of silica gel G packed in a sintered glass funnel. The product is eluted with 400 ml. of chloroform using a' acuum. The chloroform is evaporated in vacuo affording 300 mg. of benzhydryl 7-amino-7-methoxycephalosporanate as a yellow oil.

A. Benzjhj^d ^l J7-^ To a solution of 217 mg. benzhydryl 7-azido-7- bromocephalosporanate in 15 ml. of absolute ethanol is added 31.6 of pyridine -and 78 mg. of silver fluoroborate and the mixture stirred at room temperature for 2 hours, protected from light and noisture. The mixture is evaporated to dryness in vacuo and the residue chromatographed on 20 g. of silica gel. Elution with chloroform affords 121 mg. of benzhydryl 7-azido-7-ethoxycephalosporanate, m.p. 144,5- l45*c; ■ '. ----- ■··-- A .solution of 320 mg, of benzhydryl 7-azido-7-ethoxycephalosporanate in 30 ml. of dj-oxane is stirred with 320 mg. of platinum oxide at room temperature under an atmosphere of hydrogen for 1 hour. An additional 320 mg. of catalyst is introduced and the hydrogenation continued for 5 hours. The mixture is evaporated under vacuum to dryness and the residue taken up in chloroform and filtered through 2 inches of silica gel and evaporated/ leaving benzhydryl 7-amino-7-ethoxycephalosporanate as a yellow oil.

EXAMPLE_4 Benzhydryl 7-amino-7-( ethox.Ycar¾on.Ylamino)-cephalosporanate A. Benzhydryl 7-azido-7-»( ethoxycarbonylan.ino)oephalosporanate Benzhydryl 7-azido-7-bromocephalosporanate (3.9 g) is added to e hylcarbamate (36 g) maintained at 65°C.

To the resulting mixture is added portionwise as a melt silver tetrafluoroborate (3.6 g.) dissolved in ethylcar-hamate- (18 g.) and the reaction mixture is maintained at .. 67-70eC. for five minutes. The mixture is then poured into ether with stirring and the resulting slurry is filtered through celite to remove the silver bromide. The ether is extracted successively with water (100 ml.) saturated aqueous sodium bicarbonate solution (100 ml.) and two portions of water (100 ml.). The extracted ether solution is dried over sodium sulfate and then evaporated under diminished pressure. The resulting residue is triturated three times with a small amount of water and then dissolved in chloroform, The chloroform solution is dried over sodium sulfate and evaporated to dryness to afford 2.1 g. of benzhydryl 7-azido-7- (ethoxycarbonylamino) cephalosporanate.

B. Benzhydryl 7-amino-7- (ethoxycarbonylamino) -cephalospor- anate Benzhydryl 7-azido-7- (ethoxycarbonylamino) cephalo-sporanate (1.0 g.) is dissolved in dioxane (100 ml.).

Platinum oxide (1.0 g.) is added and the reaction mixture is stirred under hydrogen at atmospheric pressure for one hour. Another 1.0 g. quantity of platinum oxide is added and the reaction mixture is again placed under hydrogen and stirred for three hours until the azide is completely reacted as determined by an infrared analysis of aliquots. The solvent is removed under reduced pressure and the residue taken up in chloroform (50 ml.) and filtered through silica gel G in chloroform in a 60 ml. sintered glass funnel. The resulting material is eluted with chloroform until 200 ml. of chloroform has been collected. The chloroform is then removed under reduoed pressure to afford benzhydryl 7-amino-7-(ethoxycarbonylamino) cephalosporanate (0.6 g).

Benzh.vdr.yl 7-hydroxymethyl-7-aminocephalosporanate 1 nitrogen in 200 ml of benzene per gram aldehyde, and the 2 water azeotropically removed over a one hour period. . 3 The solution is evaporated under reduced pressure .to give 4 a foam. The- ir (CHCl-j) shows bands at 5.60 (B-lactam) 5 and 5.75μ (esters) , while the NMR (60Hz) shows peaks at 6 (numbers are in Hz from internal TMS in CDC13) 518,516 7 (1H) , 596, .587, 575, 566 (AB quartet; 4H) , 439 (lOH) , 8 416 (1H) , 330, 328, 325, 323 '(doublet of · doublets ; 1H) , 9 311, 306 (1H) , 308, 295, 288, 274 (AB quartet; 211), 221, 0 209, 206, 187 (ΛΒ quartet; 2H),'and 119 (3H) . Thin 1 layer chromatography on 250μ silica plates with 10% 2 ethyl acetate in chloroform shows essentially one spot 3 at Rf^O.58; only traces of the starting materials can be 4 detected. ' 5 B. Benzhydryl 7-hydroxymethyl-7- (4-nitrobenzilidinamino)'" 6 cephalosporanate . ■ ■' 7 A gentle stream of nitrogen is passed into a 8 half-dram vial containing 60 mg of benzhydryl 7- (4- · , 9 nitrobenzilidinamino) cephalosporanate and after a few. 0 minutes 0.3 ml of N, N-dimethylformamide is added. The Γ nitrogen stream is continued, bubbling through the 2 greenish brown solution for ca 30 seconds, and then a 3 stream of formaldehyde gas in nitrogen, generated by 4 heating ^15 mg of paraformaldehyde in a nitrogen stroam 5 is passed through. .The color is discharged and 6 the resultant solution is evaporated to a gum under high 7 vacuum. , The gum is flushed by dissolving it in a small 8 volume of chloroform and again evaporating to a gum 9 under high vacuum. Thp product exhibits an ir (neat) s ectrum with h drox I'-lootrim and ester absor tion. , .. - ! ■ . 14346 ..1 The nmr spectrum in CDCl^ shows the expected singlet 2 for the bcnzilidine proton, and new absorption associated 3 with the hydroxymethyl group. 4 C. Benzhydryl 7-hydroxymethyl-7-arainocephalosporanate • 5 '-tosylate suit _^ " 6 A mixture of 100 mg of powdered 2,4-dinitro- 7 phenylhydrazine, 85.5 mg of £-toluene sulfonic acid 8 monohydrate, and 3 ml of absolute ethanol are stirred 9 for 30 minutes. To this is added a solution of 304 mg 10 of benzhydryl 7-hydrbxymethyl-7- (4-nitrobenzilidinaniino) ! 11 cephalosporanate in 3 ml of ethanol and 0.5 ml of methylene 12 chloride. The mixture is stirred for 30 minutes, 13 filtered, and after the filter cake has been thoroughly 14 washed with ethanol, the filtrates are evaporated under 15 reduced pressure at or below ambient temperature. The 16 resultant solid is washed scvcrr.l timcc with ether nd 17 dried in a nitrogen stream. The ir and nmr of the product 18 are consistent with the assigned structure. 19 D« Benzhydryl 7-hydroxymethyl-7-aminocephnlospor n e 20 A mixture of 3.5 ml of ether, 0.5 ml of ethyl 21 acetate, 2 ml of water and 22 mg. of dipotassium hydrogen 22 phosphate is prepared. To this is added 100 mg of 23 benzhydryl 7-hydroxymethyl-7-aminocephalosporana te 24 tosylate salt and the mixture is shaken vigorously for 25 several minutes. After phase separation the aqueous phase 26 is again extracted with ether, the combined organic 27 phases are dried with anhydrous magnesium sulfate, and 28 evaporated to a gum under reduced pressure. The' product 29 is flushed several times by dissolving it in a small high vaouum. The product so obtained exhibits ir and nmr spectra consistent with the assigned structure.

By following the methods of Steps A, B, 0, and D of this example and utilizing the reagents indicated below instead of the formaldehyde of Step B above, there is obtained ... — I benzhydryl 7- amino-7-allyl- (or benzyl) cephalosporanate using allyl '', ■ chloride or benzyl chloride instead of formaldehyde; J benzhydryl 7-amino-7-carboxy- (or dithiocarboxy) cephalo-| . .sporanate using carbon dioxide or carbon disulfide for ' the formaldehyde; benzhydryl 7-amino-7-nitrocephalo- sporanate using acetone cyanhydrin nitrate for the ' ' ' formaldehyde. ' The compounds 7- (p-nitrobenzylideneamino) -7- nitroso-cephalosporanic acid benzhydryl ester; 7-(p- nitrobenzylideneamino) -7-carbamoyl-cephalosporanic acid i . benzhydryl ester;. 7- (p-nitrobenzylideneamino) -7-carbo- (i , ethoxy-cephalosporanic acid benzhydryl ester) . 7-(p-nitr0 be zylideneamino) -7-sulfocephalosporanic acid benzhydryl 1 1. eeter» 7- (p-nitrobenzylideneamino) -7-aulfamoyl-oephalo-2 sporanic acid benzhydryl ester; 7- (p-nitrobenzylidene- i 3 amino) -7-methylsulfo-cephalosporanic aoid benzhydryl 4 ester; or 7- (p-nitrobenzylideneamino) -7-phospho-oephalo- 5 sporanic acid benzhydryl ester can be prepared using the 6 . reagents nitrosyl chloride, carbamoyl chloride, ethyl- 7 chloroformate , .sulfamoyl chloride, methanesulfonyl 8 chloride, or phosphorus oxychloride , respectively. 9 The above imino derivatives can all be 0 regenerated to the amino functionality using either 1 aniline hydrochloride or 2 ,4-dinitrophenylhydrazine , as 2 - described infra. The products thereby obtained are 7-3 amino-7-nitro-cephalosporanic acid, 7-amino-7-nitroso-4 cephalosporanic acid, 7-amino-7-carbamoyl-cephalosporanic 5 acid, 7-amino-7-carboethoxy-cephalosporanic acid, 7-aminor 6 7-sulfo-cephalosporanic acid, 7-amino-7-sulfamoyl-cephalo-7 sporanic acid, 7-amino-7-methylsulfo-cephalosporanic acid 8 and 7-amino-7-phospho-cephalosporanic acid, respectively. 9 In all cases, the benzhydryl ester is the ester made.

* EXAMPLE 6: ■ Benzhydryl 7-aninocophnlosporanate-S-oxide 0.500 g. of benzhydryl 7-aminoccphalosporanate is dissolved in 10. ml. of CH2C12 cooled to 0°C. and treated with m-chloroperbenzoic acid (0.172 g.) for 1 hour, during which the reaction mixture is allowed to come to room temperature.

The reaction mixture is diluted with CH2C12 and washod with 5% NaHCO^ solution three times and then with water, dried and evaporated to give the crude product.

This is stirred with 10 ml. of other for 1 hour. The precipitate is filtered and washed with ether to give the title product.

In like manner other 7-aminodecophalosporanic acid esters described herein can be converted to the S- oxidos. These oxides can be used as intermediates in the preparation of the sulfoxides set forth in formula I above. Alternatively, the various intermediates and final products described herein can be converted to the corresponding S- oxides following the procedure described above. The various S-oxide derivatives can be converted to the corresponding cephem compounds in accordance with the process of the example which follows.

■ ! A· ■ EXAMPLE 7· ' At ·.. Trine hy silyl 3-carbanoy].oxymethyl-7-amiho- doccphalqsnoranato A mixture of 0.5 g. of 3-carbamoyloxyraethyl- 7-aminodecephalosporanic acid, 2 ml. of hexamethyldi- eilazane and 8 ml. of chloroform is stirred overnight at reflux temperature protected from moisture. The solvent and excess hcxanothyldisilazane are removed at reduced pressure, leaving a residue containing trimeth Isilyl 3-carbamoyloxymothyl-7-aminodecephalosporanate. *« .... ... ·- ·· . ., -^ > D.

A mixture of trimethylsilyl 3-carbamoyloxymethyl- 7-arainodecephnlocporanatc, 0.05 ml. of trifluoroacetic acid and 5 ml..„of chloroform is stirred at 0°C. and 0.2 ml. of isoamylnitrite is added. After stirring for 1 hour at 0°C. the resulting reaction mixture containing the trimethylsilyl 3-carbamoyloxyraethyl-7-diazodecephalosporanate is used | directly in the next step.

C. 3-Carbamoyloxymethyl-7-azido-7-bromodecephalosporanic acid . v. ' 1 To the solution obtained in B above is added at 0°C. 5 ml. of nitromethane . This is followed in rapid succession by 1 ml. of a methylene chloride solution of trirnethylamrnonium aside and 1.5 ml. of a methylene chloride solution of bromine azide, both of which arc in considerable excess of the amount required. The bromine azide is de-' colorized rapidly and nitrogen is evolved. After about 5-10 minutes 20 ml. of 0.1 N sodium tniosulfate is added and the layers are separated. The aqueous phase is adjusted to pH 2 b the addition of a few drops of hydrochloric acid and is extracted twice with methylene chloride. The combined extractions are washed with water, dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford 3-carbamoyloxymethyl-7-azido-7-bromodecephalosporanic acid.

The 3~ arbamoylo::ymethyl-7-aminodacephalosporanic acid used, as the starting material in this example can bo · prepared by the following procedures: 7-Aminocephalor.poranic acid is reacted with t- butoxycar-bonylazide to produce the 73- (t-butoxycarbonyl) derivative in accordance with known methods. This derivative is then intimately contacted with citrus acetylesterase in aqueous phosphate buffer at pH 6.5-7 for 15 hours and 3- hydroxymethyl 73- (t-butoxycarbonyl) minodecephalosporanic acid is recovered from the resulting reaction mixture.

To 0.2 g. of 3-hydroxymethyl 7(3- (t-butoxycarbonyl) - aminodecephalosporanic acid suspended in 5 ml. of aceto- nitrile, cooled to 0°C. and maintained under nitrogen atmos- phere is added 0.15 ml. of chlorosulfonyl isocyanate. The reaction mixture is stirred for 70 minutes and then evaporated' under diminished pressure to dryness. The resulting residue is taken up in 10 ml. of ethylacetate and 10 ml. of 0.1 N phosphate buffer. The pH of the aqueous layer is adjusted to about 1.6 and the mixture stirred for 2 1/2 hours at room temperature. The pH is then adjusted to about 8 with aqueous tripotassium phosphate solution, and the aqueous phase is separated. The organic phase is re- extracted with 10 ml. of phosphate buffer at pH 8. The combined aqueous phase , is' adjusted to pll 2.1 with hydro- chloric acid and extracted twice with ethylacetate. The ethylacetato extractions are dried over sodium sulfate and' evaporated under diminished pressure to afford 0.05.5 g. of residue. This residue is washed with ether to afford 3-carbamoyloxymcthyl-73- ( t-butoxycarbonyl) aminodcceplialo- s oranic acid which is recovered as a e low s l- 2 decephalosporanic ncid (0,5 g.) in 3.5 ml. of anisolo is 3 stirred with 2 ml. of trifluoroacetic acid at 0°C. for 4 5 minutes. The resulting reaction mixture is evaporated 5 under reduced pressure to afford 3-carbamoyloxymethyl-7- 6 aminodecephalosporanic' acid which is purified further 7 by crystallization from aqueous isopropanol. 8 EX/MPLE 8 \ ' ■< 9'A. p-Methoxybenzyl 3-methyl-7-azido-7-chloro- 0 decephalosporanate p-Methoxybenzyl 3-methyl-7-diazodecephalosporanate (0.9 g.) is dissolved in a mixture of 10 ml. of methylene chloride and 10 ml. of nitromethane . To this cooled solu- tion at -10°C. is added a solution of triethykmnonium azidc ··■■ prepared as described in Example 2C and a methylene chloride solution of chlorineazide (0.31 N, 15 ml) and then > 50 ml. of water. The resulting reaction mixture is adjusted "'- to pH 8 by the addition of solid sodium bicarbonate. The ' mixture is allowed to stand and the organic layer is separated, extracted with 2 x 20 ml. of water, dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford p-methoxybenzyl 3-methyl-7-3 azido-7-chlorodecephalosporanate. 4 B. When an equivalent amount of benzyl 7-diazo-5 cephalosporanate, benzhydryl 7-diazocephalosporanate , 6 phenacyl 3-benzoylthiomethyl-7-diazodeccphalosporanate , 7 · ' ¾ " trimethylsilyl 3-carbamoyloxymcthyl-7-diazodecephalosp0ranate , 1434G benzyl 3-picolinoylthioincthyl-7"diazodecGphalosporanate, benzhydryl 3-pyridiniunmethyl-7-diazodccephalosporanate, benzhydryl 3-N- (2-chloroethyl) carbamoyloxymethyl-7-diazo-decephalosporanate, t-butyl-7-diazocGphnlosporanate or benz-hydryl 3-n-anyloxynethyl-7-diazodecephalosporanate is sub-stituted for the p-methoxybenzyl 3-methyl-7-diazodecephalo-sporanate in the process of Example 42A, the following compounds are obtained: Benzyl 7-azido-7-chlorocephalosporanate Benzhydryl 7-azido-7-chlorocephalosporanate Phcnacyl 3-benzoylthiomethyl-7-azido-7~ chlorodecephalosporannte Trimeth lsily1 3-oarbamoyloxymethyl-7-azido- · 7-chlorodecephalosporanate Benzyl 3-picolinoylthioraethyl-7-a7.ido-7~ chlorodecephalosporanate Benzhydryl 3-pyridiniumnethyl-7-azido-7~ chlorodecephalosporanate Benzhydryl 3-N- (2-chloroethyl) carbanoyloxy- methyl-7-azido-7~chlorodecephalosporanate t-Butyl-7-azido-7-chlorocephalosporanate , Benzhydryl 3-n-amyloxymethyl-7-azido-7- chlorodecephalosporanate.

EXAMPLE 9 Benzhydryl 7-amino-7-acetoxycephalosporanate A. Benzhydryl 7-acetoxy-7-azidocephalosporanate Λ mixture of 2.2 g. of benzhydryl 7-azido-7-bromo- cephalosporanate and 0.8 g. of silver acetate in 10 ml. of acetic acid is stirred at room temperature for 3 hours. The acetic acid is removed under reduced pressure and the residue taken up in methylene chloride and filtered. The filtrate is washed with sodium bicarbonate solution, then dried over sodium sulfate and evaporated. The residue is · chromatographed over 80 g. of silica gel. Elution with chloroform yields benzhydryl 7-acetoxy-7-azidocephalo-sporanate. .· B. Benzhydryl 7-aroino-7-acetoxycephalosporanato 2 g. of benzhydryl 7-acetoxy-7-azidocephalosporanate in 200 ml. of dry dioxane is h'ydrogenatcd at room tempera-ture and atmospheric, pressure in the presence of 2 g. of platinum oxide for 1 hour. Fresh catalyst (2 g.) is added and the hydrogcnation continued for 2 hours. The solvent is evaporated and the residue is dissolved in other and shaken with 10 ml. of powdered anhydrous magnesium sulfate and filtered through diatomaceous earth in a frittered glass funnel. The filtrate is evaporated, leaving benzhydryl 7-amino-7-acetoxycephalosporanate.

EXAMPLE 10 · ί ' Benzhydr.yl-7g-cyano-7"ainirxoce^hal03POranate ! 4 Λ. Donzhydryl7rt-cyc.ino-7-azidocepha or.poranato ' 5 To a solution of )ienzhydryi-7-bromo-7-azido- 6 cephaiosporanate (Q.543 g. 0.001 mole) in 10 ml of 7 Cll^CN is added a solution of 0'.350 g of tetrabutyl 8 ammonium cyanide in 15 ml of CH^CN. The reaction (mixture 9 is stirred at room temperature overnight, diluted with 10 CHjClj and washed with water, dried and evaporated. | 11 Chromatography on silica gel gives the benzhydryl. 12 7u-cyano-7-azidocophalosporanate and the benzhydryl. 13. 73-cyano-7-azidoccphalosporanate. , 14 . The tetrabutyl ammonium cyanide is prepared, 15 as follows t 16 1 G of tetrabutylammoni-um iodide is dissolved 17 in 10 ml of a 20% aqueous NaCN solution. The aqueous 18 phase is discarded. The organic phase is treated with . 19 3 further 5 ml quantities of the NaCN solution. The ' 20 organic phase is dried over MgS04 and cvaporat¾d to give 21 tetrabutylammonium cyanide. 22 B. Benzhydryl 7a-cyano-7-aminocephalosporanate 23 0,500 G of benzhydryl 7a-cyano-7-azidocephalp- 24 sporanate is dissolved in 50 ml of ethyl acotato, Q.SjQQ g 25 of 10ft Pd on carbon catalyst is added and the mixture is 26 stirred under H2 overnight. The catalyst is filtered 27 off, the filtrate is evaporated and the residue, is ■ 14346 EXAMPLE 11 A. Benzhydryl 7-azido-7-carboxycephalo-sporanate Benzhydryl 7-azido-7-bromocephalosporanate (5.43 g., 0.01 mole) is dissolved in 20 ml. of dry , ether and cooled to -20°C, and 10 ml. of 1M phenyl lithium solution is added slowly with vigorous stirring.

After 1 hour at room temperature the mixture is poured onto pulverized dry ice. The residue is extracted with water and acidified to yield benzhydryl 7-azido-7-sarboxy-cephalosporanate .

B. Benzhydryl 7-azido-7-chloroformylcephalosporanate Benzhydryl 7-azido-7-carboxycephalosporanate> (4.0 g.) is added to 15 ml. of thionyl chloride and the mixture stirred in an ice bath for 1 hour. The excess thionyl chloride is removed in_ vacuo ard the residue flushed with dry acetone to give crude benzhydryl 7-azido-7-chloroformylcephalosporanate .

C. Benzhydryl 7-azido-7-carbomethox ycephalosporanate Benzhydryl 7-azido-7-chloroformylcephalosporanate (2.63 g.# 0.005 m.) .. is dissolved in methylene chloride (15 ml.) at 5°C. Pyridine (40 mg.) and methanol (1.0 ml.) are added slowly. The solvent is removed iii vacuo and . the product isolated by chromatography on. silica gel.

D. Benzhydryl 7-amino-7-carbometh oxycephalQsporanate 1.0 g. of benzhydryl 7-azido-7-carbomethoxy-celphalsporanate is dissolved in 100 ml. of dioxane. 1.0 g. of platinum oxide is added and the reaption mixture stirred under hydrogen at atmospheric pressure for 1 hour. , ' Another 1.0 g. quantity of platinum oxide is added, and the reaction mixture is again placed under hydrogen and as determined by infrared analysis of aliquots. The solvent in removed under reduced presoure and the rooidue taken up in 50 ml. of chloroform and filtered through . silica gel G in chloroform in a 60 ml. sintered glass funnel. The material is oluted with chloroform until 200 ml» of chloroform has been collected. The chloroform is removed under reduced pressure affording 0.632 g. of benzhydjj:yl-7-amino-7-carbo me thoxycephalosporanate, >< which may he acylated directly without further purification to form the corresponding compound of formula X. 1 EXAMPLE 12 2 Λ. Benahydryl 7-othynyl-7-a,/idocephnlosporanato 3 A stirring solution of 0.900 g of benzhydryl 4 7-diazocophalospbrnnate in 10 ml each of methylene chloride 5 and ether is cooled to -78 °G. under a nitrogen atmosphere 6" and is treated dropwiso with a solution of triethynyl- 7 boron. The addition is halted periodically, and the pro- . 8 gress of the reaction is ascertained by infrared analysis 9 of small aliquots. When the diazo compound has complete- · ° ly reacted, the remaining triethynylboron solution is H discarded. Bromine azide in methylene chloride, 25 ml 12 of a 0.28N solution, is then added over a period of 20 13 min. The cooling bath is removed and the mixture is 14 stirred for a further 60 min, at room temperature, 15 The reaction mixture is poured onto a solution 16 of 20 ml. of 0.1N sodium thiosulfate and 20 ml of 0.5 17 pH 7 phosphate buffer and agitated. The organic phase is separated, washed with water and saturated brine, 9 dried over anhydrous magnesium sulfate, and evaporated 0 ill vacuo■ The residue is chromatographed on silica gel using benzene as eluant to afford benzhydryl, 7a-ethynyl- The tricthynylboron solution uoed above io prepared as follows: A solution of 5.42 g of boron \ trifluorido in 20 ml of ether is stirred at 078°C. under a nitrogen atmosphere while 2.80 g of sodium acetylide in 20 ml of xylene is added over a period of 90 min. The reaction mixture, which is a white solid suspended in a clear liquid, is rapidly transferred to a drybox and filtered into a dry ice jacketed dropping funnel. This solution is used immediately.

At no point is the temperature of the triethynylboron allowed to exceed -60 °C.

B. Donzhydryl 7g-ethynyl-7-aminoccphalosporanate To a stirring solution of 0.028 g of anhydrous cobalt (II) bromide in 20 ml of absolute ethanol is , added 0.061 g of 2 , 2 ' -bipyridine-. After all the bi- pyridine has dissolved, a solution of 0.315 g of benzhydryl 7a-ethynyl-7-azidocephalosporanate in 5 ml of absolute 11. ethanol is added followed by 0.073 g of sodium borohydride.

The reaction mixture is stirred for 15 min. at room temperature, and is then quenched by the addition tof cold aqueous acetic acid. The mixture is diluted with i I 25' ml of water and extracted, with three 20 ml portions of ether. The combined extracts are washed with pH 7 phosphate buffer and saturated brine, and dried over anhydrous magnesium sulfate. Evaporation of the solvent under reduced pressure gives benzhydryl 7a-ethynyl-7- ma aminocephalosporanato. This material/be acylated with- EXAMPLE 15 ' Benzh.vdr.yl 7-amlno-7-( dirnethylphosphono ) cephaloaporanate 4 Step At Benzhydryl 7-Azido-7- (Dirnethylphosphono) Cephalo- 5 sporanate 6 To a solution of benzhydryl 7-azido-7-bromo- 7 cophalospora ate (272 mg., 0.0005 mole) in dimethoxy- 8 ethane (10 ml.) is added silver dimethylphosphito (120 mg., 9 0.00055 mole) (prepared by mixing equimolar amounts of 10 dimethylphosp ito and silver oxide in water and filtering 11 · the solid which slowly forms). , The mixture is stirred 12 overnight at room temperature protected from light, air,' 13 and moisture. The inorganic material is filtered and 14 the filtrate is concentrated at a low temperature and 15 pressure. The residue is dissolved in methylene chloride 16 and the solution is washed with a cold, dilute, aqueous 17 solution of sodium bicarbonate. It is dried and con- '> 18 centrated at reduced pressure. The residue is re-dis- 19 . solved in a small amount of chloroform and the mixture is 20. purified by chromatography on. silica gel using chlorofprm 21 as the elution solvent. The initial eluate contains β· 22 'little recovered starting material. The second elution 23 fraction is concentrated at reduced pressure to afford i ' 24 benzhydryl 7-azido-7- (dirnethylphosphono) cephalosporanate. 25 steP B« Benzhydryl 7-Amino-7- (Dirnethylphosphono) Cephalo- 26 sporanate . ■ ■ 27 Benzhydryl 7-azido-7- (dirnethylphosphono) cephalo- 28 sporanate (200 mg.) is dissolved in dioxane (20 ml.) and 29 hydrogonated at room temperature and normal pressure for 30 ono hour using platiniu oxide (200 mg. ) as catalyst. A 31 fresh 200 mg. -portion of catalyst is added and the 32 hydrogonation is continued for an additional two hours.

Tho solvent is removed at low temperaturo and pressure.

Tho dry residue is dissolved in chloroform and the solution is filtered by suction through a layer of silica gel to remove the suspended, spent catalyst. The silica gel is washed copiously with chloroform to elute any adsorbed material. Tho filtrate is concentrated at reduced pros-sure to afford benzhydryl 7-amino-7- (dimethylphosphono) -cephalosporanato suitable for use in the next .step without further purification. · I ■ ■ - - . . .

EXAMPLE 14 Benzhydryl 7a-hydroxymethyl-7 β-aminocephalosporanate 4 A. Benzhydryl 7a-hydroxymethyl-7 β-aminocephalo- 5 sporanate tosylate salt 6 A mixture of 100 mg of powdered 2,4-dinitro- 7 phenylhydrazine, 85.5 mg of £-toluene sulfonic acid 8 monohydrate, and 3 ml of absolute ethanol are stirred 9 for 30 minutes. To this is added a solution of 304 mg 0 of benzhydryl 7a-hydroxymethyl-7P- (4-nitrobenzylidene- 1 amino) cephalosporanato in 3 ml of ethanol and 0.5 ml 2 of methylene chloride. The mixture is stirred for 13 30 minutes, filtered, and after the filter cake has 1 14 been thoroughly washed' with ethanol, the filtrates 15 are evaporated under reduced pressure at or below B. Benzhydryl 7a-hydroxymethyl-70-aminocephalo- sporanate .

A mixture of 3.5 ml of ether, 0.5 ml of ethyl.' acetate, 2 ml of water and 22 mg of dipotassium hydrogen phosphate is prepared.' To this is added , 100 mg of benzhydryl 7a-hydroxymethyl-73-aminocephalo- j sporanate tosylate salt and the mixture is shaken , vigorously for several minutes. ' After phase. separation the aqueous phase is again extracted with 1 ' ether, the combined organic phases are dried with anhydrous magnesium sulfate, and evaporated to a gum under reduced pressure. The product is flushed several times by dissolving it in a small volume of chloroform and again evaporating to a gum under high obtained in essentially quantiative yield, vacuum. The product/ benzhydryl 7a-hydroxymethyl-70-aminocephalosporanate, is purified by preparative tic on silica gel using ethyl acetate (Rf'—0.5) . It exhibits an nmr spectrum (CDCl^) with peaks at 444 (10H); 421 (1H) , 307, 294, 289, 275 (2H) , 291 (1H) , I 235 (2H), 226, 207, 203, 184 (2H) , 158 (B, 2H) , 120 (3H) expressed in cps (cycles per second) down-field from tms (tetramethylsilane) . The ir (CHCl^) ! showed NH-OH (2.8-3.1 μ) , β-lactam (5.60 μ) and ester . (5.74 μ) absorption.

EXAMPLE 15 ' Benzhydryl 7a-methyl-7&-aminocephalosporanate '·.·'■ The benzhydryl 7a-methyl-7 - (p-nitro-benzylideneamino) cephalosporanate prepared as described below is treated with 109 mg. of 2,4-dinitrophenylhydrazine and 106 mg. of p_-toluene-sulfonic acid hydrate in 10 ml. ethanol for 1/2 hour. The mixture is filtered and the solids washed severa times with ethanol. The filtrate is evaporated in vacuo, treated in pH 8 aqueous buffer and extracted twice with ether. The ethe solution is dried with MgS04, filtered, evaporated, and the residue is chromatographed on 10 g. silica gel, eluting with 4x1 chloroform-ethyl acetate. Pure benzhydryl 7a-methyl- 70-aminocephalosporanate (81 mg.) is obtained; Rf"0.25 on tic, same system, nmr: 1.6(f (7a-methyl) , 1.9S(f (acetyl), 3.05, 3.35, 3.4, 3.7 (f (SCH2) , 4.58, 4.72, 4.85, 5.07 (f (¾OAc), 4.6 (f (6α-Η) , 6.86 ( ^f>2) , .3^ (aromatic). ir: 0-lactam and ester carbonyls at 5.63 and 5.76 μ, respectively. ► ma: 452, 382, 285. 1 Benzhydryl 7- (p-nitrobenzylideneamino) - cephalosporanate is prepared by heating an equimolar mixture, of benzhydryl 7a-aminocephalosporanate and 4-nitrobenzaldehyde under nitrogen in 200 ml. of benzene, per gram of aldehyde and removing the water , • · ί formed azeotropically. The product is recovered by | evaporating the solution under reduced pressure. ■ ·'■* · The product so obtained, 286 mg., is . dissolved in 8 ml. of tetrahydrofuran and at -78°C. under a nitrogen atmosphere 0.218 ml. of 2.3 M phenyl-^ lithium in tetrahydrofuran- is added. To the resulting solution of benzhydryl 7a-lithio-7(¾- (p-nitrobenzyli- j. deneamino) cephalosporanate is added at -78°C. under 1 nitrogen a solution of 0.4 ml. methyl iodide in 10 ml. ' dimethylformamide. After stirring 5 minutes at -7.8°C; the reaction mixture is allowed to warm to ;room tern- I perature over 1/2 hour. Benzene (100 ml.) ''is added and the solution washed six times with water; the second wash is acidified with pll 2.and the fifth with ... pH 8 phosphate buffers. The benzene solution is dried ' with MgSO^, filtered and evaporated in vacuo , leaving . 330 mg. of benzhydryl 7a-methyl-70- (p-nitrobenzylidene4 amino) cephalosporanate. : . . nmr: 1.8 (f (7a-methyl) , 1.9 (f (acetyl), 3.3, 3.4 (f (SCH2) , 4.7, 4.8 (f (CH20Ac) , 4.8 ( (6a-H) , 6.9 (f (CH 'j) ' .SSrf (CH=N) , 7.2-8.2 (f(aromatics .

-· . · ' . ■ · '! ' I ' ' ir: β-lactam and ester carbonyls at 5.64 and 5.74 i, respectively. j · EXAMPLE 16 Benzhydryl 7-amino-7-methylcephalosporanate 11 A. Benzhydryl 7-dimethylboron-7-methylcephalosporanate 12 - A solution of .228 g. of benzhydryl 7-diazo- 13 cephalosporanate in 5 ml. of methylene chloride, prepared 14 as described below, is diluted to about 10 ml. with tetra- 15 hydrofuran and cooled to about -78°C. in a dry ice bath. 16 To this cooled solution is added 3.5 ml. of trimethylboron 17 solution with stirring over a period of 10 minutes. The 18 resulting reaction mixture is allowed to stir for another 19 10 minutes at -78°C.. An infrared spectrum of a small 20 aliquot of this solution at this point shows no diazo band. 24 The trimethylboron solution used in this example 25 is prepared as follows: Methyl magnesium iodide is 26 prepared from 1.44 g. of magnesium and 8.5 g. of methyl 27 iodide in 40 ml. of ether, and the resulting Grignard 28 solution is diluted to 50 ml. with additional ether. 5 Ml., of -his solution is placed in a 3-neck round bottom flask equipped with dropping funnel, magnetic stirrer and a nitrogen inlet tube. The flask is connected . to a gas inlet tube fitted with a 2-neck flask containing 5 ml. of ether, cooled to -78°C. in a dry ice bath and both flasks are placed under a nitrogen atmosphere; the nitrogen gas being passed into the first flask and bubbled into the ether in the second flask. 0.2 ml. of boron tri fluoride etherate diluted to 2 ml. with ether is added dropwise to the first flask and the trimeth lboron formed is collected in the second flask. The flow of nitrogen is continued until much of the ether in the first flask is flushed into the second flask to give about 9 ml. of trimethylboron solution.

B. Benzhydryl 7-azido-7^methylcephalosporanate To the solution of benzhydryl 7-dimethylboron-7-methylcephalosporanate prepared as described in A above is added a solution of bromine azide in methylene chloride pre-pared as described below. The resulting reaction mixture turns orange and is allowed to stir overnight at room tem-perature. It is then poured into cold N/10 sodium thiosul-fate solution. The organic phase is separated, washed with an equal quantity of aqueous 5% sodium bicarbonate solution and then with water. The washed organic phase is then dried over sodium sulfate and evaporated to give benzhydryl 7- . azido-7-methylcephalosporanate.

The solution of bromine azide is prepared as follows: To a solution of .2.4 gm. of sodium azide in 4 ml. 1 of water is added 40 ml. of methylene chloride and the mix- 2 ture cooled to 0°C. To this cooled mixture is added drop- * 3 wise 4 ml. of 50% aqueous sulfuric acid (vol./vol. ) over 4 .5 minutes and the mixture is allowed to stir another 5 5 minutes. The aqueous layer is frozen b cooling in a solid 6 carbon dioxide bath and the organic phase is decanted off 7 and' dried over anhydrous sodium sulfate. To this solution , 8 of the hydrazoic acid is added 2 g. of N-bromosuccinamide 9 and the mixture is stirred for Ϊ5 minutes at.0°C. until all 10 the N-bromosuccinamide is dissolved. 11 ..' ■' ' '· ' ' :.' 12 C. Benzhydryl 7-amino-7-methylcephalosporanate 13 1.0 g. of benzhydryl 7-azido-7-methylcephalosporanate 14 is dissolved in 100 ml. of dioxane. 1.0 g. of platinum oxide 15 i^ added and the reaction mixture stirred under hydrogen at 16 atmospheric pressure for 1 hour. Another 1.0 g. quantity 1' of platinum oxide is added, and the reaction mixture is 8 again placed under hydrogen and stirred for 3 hours- until I9 the azide is completely reacted as determined by infrared 2^ analysis of aliquots. The solvent is removed under reduced 2·^ pressure and the residue taken up in 50 ml. of' chloroform 22 and filtered through silica gel G in chloroform in a 60 ml. 23 sintered glass funnel. The material is eluted with chloro- I 24 form until 200 ml. of chloroform has been collected. The 25 chloroform is removed under reduced pressure affording 26 0.632 g. of benzhydryl 7-amino-7-methylcephalosporanate , ( The starting material in A above , benzhydryl 7- diazocephalosporanate, is prepared as follows t To a slurry of 6.8 g. (.025 mole) of 7-aminocephalosporanic acid in , 300 ml. of peroxide-free dioxane at room temperature is added with stirring 4.3 g. (.022 mole) of p-toluenesul- fonic acid monohydrate. The clear solution is concentrated in vacuo and flushed twice with dioxane.

The residue is dissolved in 300 ml. of dioxane at room temperature, and a solution of 10 g. (.05 mole) of diphenyldiazomethane in 25 ml. of dioxane is added drop- wise over 15 minutes. The wine-colored solution is stirred for an additional 30 minutes, then 25 ml. MEOH is added to, destroy the excess 02CN2 * Tne mixture is concentr vacuo and the residue partitioned between.200 cc. and 200 ml. water containing 10 g. K2HP04 (pH 8.5) organic phase is washed with water, dried over_ a2 concentrated in vacuo to yield an oil.

The oil is stirred with 100, ml. of ether 1 hour. The precipitate is filtered, washed with ether ! I and dried to constant weight to afford 4.7 g. of benzhydryl! ; 7-aminocephalosporanate. m.p. 126-128eC. Analysis .;..' calculated: C, 63.0; H, 5.01; N, 6.37. Pound: C, 62.7;. H, 5.18i N, 5.18. IR in CHC13 is 5.6 μ (β-lactam OO) and }. 5.8 μ (ester C=0) . NMR in CDC13 is 1.85 ζΓ(singlet, NH2) ; CH2S) ; 4.Q(f ,, ·| > (singlet, CH2OAC) ; .7^ (doublet, CgH) ; 4.9^ (doublet, C?H); 6.98< (doublet, ^CH) ; and 7.4^ (singlet, phenyl)', j < To a stirring, mixture of 1.6 g. of NaN02, 30 ml. of water and 40 ml. of CH2C12 at 0°C. is added 880 mg. . (. ! (.002 mole) of benzhydryl ester followed by the addition ' of a solution of 760 mg. (.004 mole) of p-toluenesulfonio . acid in 5 ml. water over a few minutes. The mixture is stirred at 0°C. for 20 minutes, then the organic phase is cut away, washed with 1 x 10 cc. ice water, dried over Na2SO^ at 0°C. , filtered and concentrated in vacuo at room tempera-; ture to yield 900 mg. of benzhydryl 7-diazocephalosporanate j in the form of a glass. IR is 4.8 μ (strong N=N) , 5.6 μ j • o ' τ· 2.0 EXAMPLE 17 Benzhydryl 7-trifluoromethyl-7-amlnocephalosporanate A. Benzhydryl 7-difluoromethylenecephalosporanate . Benzhydryl 7-diazocephalosporanate (4.5 g., 0.01 mole) in 10 ml. of dry dioxane is added to a solution of 4.1 g. of 0.05 mole thiocarbonyl fluoride and allowed to stand at room temperature until the reddish color of the diazo compound disappears. The reaction mixture is heated at reflux for 45 minutes and the solvent removed in vacuo. The product is chromatographed on silica gel using chloroformmethanol as the eluant to afford benzhydryl 7-difluoromethylenecephalosporanate.

B. Benzhydryl 7-trifluoromethyl-7-bromocephalosporanate Benzhydryl 7-difluoromethylenecephalosporanate (2.35 g., 0.005 mole) and finely powdered silver mono-fluoride (1.90 g. , 0.015 mole) in 50 ml. of benzene are vigorously stirred. Bromine (0.80 g. , 0.005 mole) is added dropwise. Benzhydryl 7-trifluoromethyl-7-bromo-cephalosporanate is isolated by chromatography on silica gel.

C. Benzhydryl 7-^trifluoromethyl-7-aminocephalosporanate Benzhydryl 7-trifluoromethyl-7-bromocephalosporan'!' ate (1.14 g. , 0.002 mole) is dissolved in 20 ml. of dry ether and cooled to -20°C. To this cooled solution is slowly added .0.4 ml. of 5 ethereal methyllithium solu- -10°C. for 1/2 hour and allowed to warm to room temperature before heating at reflux for 2 hours. The.ether is re-moved in vacuo and the benzhydryl 7-trifluoromethyl-7-'aminocephalosporanate is isolated by chromatography on silica gel.

EXAMPLE 18.

Benzhydryl 7a-(l-hydroxyethyl)-70-aminocephalosporanate To a slurry of 272 mg. of 7-aminocephalosporanic aoid in 7 ml. of dioxane with 170 mg. of p-toluenesulfonic acid monohydrate is added 2 ml. of methanol. The solvents are removed in vacuo and dioxane is added twice and evapo- rated in vacuo. To the residue is added 8 ml. of dioxane and then 290 mg. of diphenyl diazomethane. After the evolution of the nitrogen is completed, the solvent is evaporated in vacuo and the residue stirred with 10 ml. of methylene chloride and 10 ml. of water containing sufficient dipotassium acid phosphate to bring the pH to 8. The layers are separated and the aqueous portion extracted twice more with methylene chloride. The combined organic layers are dried with sodium sulfate, filtered and evaporated, leaving oily crystals of benzhydryl 7-aminocephalosporanate.

Washing of the oily crystals with ether affords a dry solid (150 mg.) having a melting point of 110-115°C.

Benzhydryl 7-aminocephalosporanate (438 mg.) is refluxed 1 hour in 50 ml. of benzene with 151 mg. of p-* nitrobenzaldehyde in an azeotropic drying apparatus. The solvent is then evaporated under vacuum leaving 571 mg. of crude benzhydryl 7- (p-nitrobenzylideneamino) cephalosporanate.

To a solution of 500 mg. of benzhydryl 7- (p- nitrobenzylideneamino) cephalosporanate in 5 ml. of aceto- nitrile at 20°C. is added 150 μΐ. of N ,Ν-diisopropylethyl- amine followed by 385 μΐ. of acetaldehyde . The resulting t solution is stirred 5 minutes at 20°C. and evaporated I to afford 500 mg. of benzhydryl 7a- (l-hydrox ethyl) -7- (p- . nitrobenzylideneamino) cephalosporanate . The ir and nmr indicate the product has the assigned structure..

A mixture of 160.5 mg. of p-tolueriesulfonic acid, 173. 6 mg. of 2 , 4-dinitrophenyl hydrazine and 10 ml. of absolute ethanol are stirred for 1/2 hour at room tempera- ture. To this mixture is added a solution of 500 mg. of , benzhydryl 7a- (1-hydroxyethyl) -7- (p-nitrobenzylideneamino) -'·" cephalosporanate in 6 ml. of 30% methylene chloride-absolute ethanol and stirred for an additional 1/2 hour at. room' temperature. The mixture is then filtered and the solid washed with ethanol. The filtrate is evaporated to. dry- ·. ness to afford 510 mg. of benzhydryl 7a- (1-hydroxyethyl) - 73-aminocephalosporanate tosylate. j ' The tosylate salt (510 mg.) is suspended in! 18 ml. of ether and 3 ml. of ethyl acetate to which is added, a . solution of 112 mg. of dipotassium acid phosphate in 10 ml.. of water. The mixture is shaken several minutes until both phases become clear. The organic layer is separated and the aqueous layer is extracted again with ether. The com- bined ether extracts are taken to dryness to afford 350 mg. of benzhydryl 7a- (1-hydroxyethyl) -73-aminocephalosporanate -' EXAMPLE 19 4 Benzhydryl 7a-methyl-7g-arninocephalosporanate Benzhydryl 7- (p-nitrobenzylideneamino) cephalo-sporanate (286 mg.) is dissolved in 8 ml. of tetrahydro-furan. At -78eC. under nitrogen atmosphere 0.218 ml. of 2.3 phenyllithium is added, forming the 7a-lithio derivative .

To this product is then added at -78°C. under nitrogen a solution of 0.4 ml. of methyl iodide in 10 ml. of dimethylformamide. After stirring 5 minutes at -78°C. the reaction mixture is allowed to warm to room temperature over 1/2 hour. Benzene (100 ml.) is added and the solution .'. washed six times with water; the second wash being acidified with pH 2 and the fifth with pll 8 phosphate buffers. The benzene solution is then dried with magnesium sulfate, filtered and evaporated in vacuo to afford 330 mg. of benzhydryl 7a-amino-7- (p-nitrobenzylideneamino) cephalo- " """ sporanate, nmr: l.Btf (7a-methyl) , 1.9 rf (acetyl) , 3.3, ,lA( {Sai2) , 4.7, .8 (CH2OAc) , 4.8^ (6a-H), 6.9^' (CHjZ>2), 8.65^ (CH=N), 7.2-8.2 ^ (aromatics). ir: β- lactam and ester carbonyls at 5.64 and 5.74" μ, respectively.

This product is then treated with 109 mg. of 2,4- dinitrophenyl hydrazine and 106 mg. of p-toluenesulfonic acid monohydrate in 10 ml, of ethanol for 1/2 hour. The mixture is filtered and the solids washed several times with ethanol. The filtrate is evaporated in vacuo, treated with pH 8 aqueous buffer and extracted twice with ether.

The ether solution is dried with magnesium sulfate, filtered, evaporated, and chromatographed on 10 g. of silica gel.

Pure/tenzhydryl 7a-methyl-7&-aminocephalosporanateN)(81 mg) is obtained, nmr: (f(7a-methyl) , 1.95 (f (acetyl), 3.05, 3.35, 3.4, 3.Ί (f (SCH2) , 4.58, 4.72, 4.85, 5.07

Claims (28)

CLAIB3

1. 3^2A-7-emla -7-Hx-^ephei^-carbo .lic acid of the formula and the corresponding 3-oxidea, and salts and eaters thereof, wherein A represents hydrogen, hydroxy, halo, azido, cyano, mercapto, alkox , aralkoxy, picalinylthio 1-methyl-l , 2 , 3 , 4-tetrazol-5-yl-thio, alkylthio', aralkylthio, acyloxy, acylthio, alkylsulfonyloxy, carbamoyloxy, N-p-sulfonylphenylcarbamoyloxy, carbamoylthio or a quaternary ammonium group and represents halo, hydroxy, .mercapto, alkoxy, alkylthio, acyloxy, acylthip, aralkoxy or aralkylthio in which the alkyl or aralkyl group may be substituted with halo, riitro , hydroxy, carboxy, sulfinyl or sulfonyl groups; loweralkyl, loweralkenyl, loweralkynyl, aralkyl, a cyano, .phosphono or alkyl-substituted phosphono ■ group, or a group -of the formula -CX'R" wherein X' is oxygen or sulfur,, and R" is hydrogen, halo, hydroxy,, mercapto, alkyl, alkoxy or alkylthio or R1 is a nitrbgen-bonded group such as amino, alkylamino, nitro, azido , or alkoxycarbonylamino groups , 46413/2

2. Compounds according to Qlaim 1, wherein the eater is methyl,, trichloroethyl, allyl, benzyl, benzhydryl, o-nitr(*¾ benzyl, p-methoxybenzyl, trimeth lsilyl or phenacyl, and the acyl group of the aoyloxy or acylthlo substituent A is a lower-alkgnoyl, thiocarbamoyl, carbamoyl, I-alkylcarbamoyl, N,lf-dialh;yl-carbamoyl or oarboalkoxy,

3. Compounds accordin to Claim 2, wherein A is acetoxy, carbaiaoyloxy, hydrogen, loweralkoxy or pyridini m.

4. Compounds according to Claim 1, wherein ^ is hydroxy, mercapto, alkoxy, alkylthio, aralkoxy or aralkyIthio.

5. Compounds according to Claim 4, wherein R^ is XR*^ wherein X represents oxygen or sulfur and R'^ represents alkyl or aralkyl and preferabl where R^ is methyl, and X is oxygen.

6. An ester of the product of Claim 4 where ^ is methoxy and the ester group is methyl, trichloroethyl, allyl, benzyl* benzhydryl, o-nitrobenzy1, p-methoxybenzyl, trimetlSyl-silyl or phenacyl.

7. 2he product of Claim 5 wherein A is acetoxy or carbaiaoyloxy .

8. ¾he product of Claim 7 which is ben&ydryl 3- acetosy-meth l-(or 3-earbamoyloxymeth l)-7-^ 4-carboxyl e.

9. The product of Olaim 5, wherein A is hydrogen, alkoxy or pyridinium, and preferably benzhydryl 3-methyl-7-methoxy-7-amino-3-cephem-4-oarbox late , benzhydryl 3-methoxy-methyl-7-methoxy-7-andno-3-cephem-4-oarboxylate, and benzhydryl 3-pyridiniummethyl-7-methoxy-7-amino-3-oephem-4-carboxylate. 'j ,

10. Compounds of formula' I in Claim <1 substantially as desoribed herein with reference to the Examples* '

11. A process for preparing 3-CH2A-7-amino-7-R1-3- · oephem-4-carboxylic acid of formula X in Claim 1 and the ' corresponding S-oxides and salts and esters thereof whioh comprises react 4-carboxylio ac wherein A and ^ have the same meaning as in Claim .1 and the group RQ is alkyl, aoyloxy^juethyl, haloalkyl, alkenyl, 46413/2 - 75 - and, if desired, converting the ester to the free acid or salt thereof.

12. A process according to Claim 11, wherein the ester group RQ is a methyl, trichloroethyl, allyl, "benzyl, benz-hydryl, o-nitrobenzyl, p-methoxybenzyl, trimethylailyl or phenacyl group.

13. _ A. process accordin _ to -Claim 11 or 12, wherein the. acyl moiety of the acyloxy or acylthio substituent A in formula VIII is a loweralkanoyl, thiocarbamoyl, carbamoyl, N-alkylcarbamoyl, N,N-dialkylcarbamoyl or carboalkoxy, and preferabl an- acetyl or-carbamoy-1 group.

14. A process according to Claim 11 or 12, wherein the substituent A in formula VIII is hydrogen, loweralkox or pyridinium.

15. A process according to any of Claims 11 to 14 wherein in formula VIII is hydroxy, mercapto, alkoxy, alkylthio, " ^ i aralkoxy or aralkylthio.

16. A process according to any of Claims 11 to 15» wherein R^ in formula VIII is a group XR'-^ wherein X represents oxygen or sulfur and R'^ represents alkyl, alkenyl, alkynyl, oi— aralkyl ' / optionally containing one or. more, hydrox , halo, nitro, ' jcarboxy, sulfinyl or sulfonylisubstituents preferably X is oxygen and R'^ is methyl.

17. A prooess according to Claim 11 wherein R^ in formula VIII is alkyl or alkynyl and preferably methyl 46413/2

18. A process according to Claim 11, wherein R^ in formula VIII represents cyano, phosphono, or alkyl-substituted phosphono, halo, or a nitrogen bonded group, preferably amino, azido or nitro.

19. A process, according to. Claim 11, wherein R^ in formula VIII represents -CX'R" wherein X' is oxygen or sulfur, and R" is hydrogen, halo, hydroxy, mercapto,. alkyl I alkoxy or alkylthio. j

20. A process · according to any one of Claims 11 to 19, wherein the 7-azido compound of formula VIII is prepared by reacting a 7-halo-7-azidocephalosporanic aoid ester of the formula in which A and Rg have the same meaning as in Claim 11 and X is halogen with a suitable nucleophilic reagent for replac ing X with .

21. A process according to Claim 20, wherein the nucleophilic reagent is an alcohol, a halo or alkoxy substituted alcohol, an amide alcohol or an amide ester.

22. A process according to Claim 20, wherein the starting compound of formula VII is prepared by reacting a 7-diazocephalosporanic acid ester of the formula in which A and RQ have the same meaning as in Claim 11 with a halo azide, preferably in the presence of an alkali metal or tertiary ammonium azide.

23. A process according to Claim 22, wherein the compound of formula III is prepared by reaction of the corresponding 7-aminocephalosporanic acid ester of the formula wherein A and .Rg have the same meaning as in Claim 131, with a diazotizing agent.

24. A process according to Claim 20 for the preparation of compounds of formula VIII in whioh is an azido group which comprises reacting the 7-halo-7-azidocephalosporanic acid ester of formula VII in Claim 20 with an alkali metal azide, preferably lithium azide, to form the corresponding 7,7-diazidocephalosporanate.

25. A process according to any of Claims 11 to 19 , wherein the 7-azido compound of formula VIII in which . is. a hydrocarbyl group is prepared by reacting a dlazo-oephalosporanio acid ester of formula III in Claim 22 46413/2 - 73 - with a trihydrocarbyl boron compound to form an intermediate of the fonaula D S I>2B . L / "\ ; I I · xvii I a J CH2A CCORg where ¾ is a hydrocarbyl radical and Eg has the same aa in Claim 11 and reacting this intermediate with a halogen azide.

26. A rocess according to Claim 20 for the preparation of coGpovmd3 of formula VIII in which is a group -CX'K" in which X' and R" have the sane sseanings aa in Claim 19 which comprises reacting the compound of formula VII in

27. Claim 20 with carbon dioxide or carbon disulfide in the presence of phen llithiuE, and if desired converting the carboxy or thiocarboxy compound into the corresponding carboxylie or thiocarboxylie acid derivative. 2i . A process according to any of Claims 11 to 19 , wherein compounds of formula VIII in which is an al-koxy, alkylthio, aralkoxy or aralkylthio group, are prepared by reaction of a cosapound of formula III in Claim 22, with a hypohalite of an alcohol or a thiol, to forai the corresponding 7-halo-7-K^ compound and the latter is reacted with a metal azide.

28. Processes for the preparation of compounds of formula X in Claim 1 and of the corresponding S-oxides, and of salts and esters thereof, substantially as described herein with reference to the Examples. t PC/rb