IL29529A - Orally active 7-(4'-(aminoalkyl)phenyl)acetamido cephalosporanic acid derivatives - Google Patents

Description

ORALLY ACTIVE ACETAMIDO C EPHALOSPOR ANIC ACID DERIVATIVES The compounds of this invention can be categorized as being cephalosporin compounds in that they fit the following general ί COOM where R represents an organic is either hydrogen or and M represents a pharmaceutically acceptable The compounds contain a double bond in the 3 a thiazine and a fused Some of the compounds of this class have shown promise as being practical antibiotics in bating diseases caused by various and microorganis A few cephalosporin for sodium cephalothin acetamidocephalosporanic sodium are being administered as a parenteral antibiotic on a substantial commercial There is a continuing need for different and improved This invention provides such an improvement in that the compounds of this invention have demonstrated substantial activity as antibiotics when administered The pounds of this invention constitute inventive advance over the compounds claimed in Patent which have not been claimed to be effective as orally administered The new compounds of this invention are the free inner and pharmaceutically acceptable salts of compounds of the wherein is hydrogen or lower alkyl having from one to two carbon and is hydrogen or which may be gle compounds or varying mixtures of stereoisomeric forms of optically active These compounds are generally pared as the zwitterion or inner They may also be used in the orm of salts with a pharmaceutic lly acceptable base such as the alkali metal salt as the sodium or tassium and the ammonium and substituted ammonium and amine salts or as the anion in a pharmaceutically acceptable anionic with a strong acid an acid addition salt with a strong acid having a of less than as the salt with hydrochloric sulfuric or trifluoroacetlo and the It ferred to manufacture and use those compounds as antibiotics in the zwitterion or of compounds of this invention are named below as the free amino acid compounds but it is understood that they can be used in the various salt indicated above acid acid cephalosporanic and oephalosporanic acid The novel cephalosporanic acid compounds of the present invention are related to cephalosporin 0 insofar as they contain the ring with a fused β ring in the which is characteristic of cephalosporin unlike cephalosporin which tains the group in the the compounds of the present invention are characterized by an acylamldo group in the having an substituent in the on the phenyl ring of a phenylacetic acid aoylatlng The new acid compounds in a methyl group in the instead of an acetoxymethyl group as does cephalosporin unlike cephalosporin which has a relatively low antibacterial the compounds of the present invention are highly effective antibacterial capable of the growth of numerous types of microorganisms in a variety of Cephalosporin which is the most convenient ing material to make the compounds of this can be prepared by cultivating a cephalosporin organism in a suitable nutrient medium as described in British patent specification published March in C may also be prepared by a method described in Patent issued March involving the use of sporin mould of the species of which is a member in a medium containing suitable nutrient materials including a source of organic the presence of molecular and the separation of alosporin C thereby Cephalosporin C is readily converted into the sponding nucleus acid by cleaving the 5 aide chain between amido carbonyl group and its suitably by acting cephalosporin C with chloride in formic then hydrolytically according to the method of et described in Patent which issued June When the desacetoxycephalosporanic acid compounds are cephalosporin C can be converted to cephalosporanlc acid by conventional by catalytic hydrogenation of cephalosporin 0 followed by drolytlc removal of the side as in Patent issued April The is then used in place the to prepare the compounds of this The cephalosporanic acid compounds of the present invention are prepared by acylation of the or 7 ADC A either as the free acid or as a suitable water soluble salt such as are described in Patent issued September 1 with an acylatlng agent of the selected acid lowing convention acylation A convenient ing agent for this purpose is the respective phenylacetyl chloride or bromide which the amino group has been protected the conventional manner with a blocking group such as carboallyloxy f or the The acylation of or is carried out in water or an appropriate organic erably under substantially neutral pH and bly at or somewhere below room above the freezing point of the reaction mixture and up to about In a typical or together with a cient quantity of sodium bicarbonate or other appropriate preferably to maintain the pH of the mixture between 5 and and to promote salt formation and dissolved in aqueous 50 volume the concentration of the or being about 1 to about percent by The solution Is cooled to around to and the of the protected chloride or bromide acylation agent is added in about 20 percent with stirring and The pH of the mixture can be if it tends to around the neutral level 6 to by adding sodium bicarbonate thereto or bubbling carbon dioxide After addition of the acylating agent has been stirring of the reaction mixture is and the mixture is allowed to warm to room temperature The reaction product is then acidified to around pH 2 with chloric acid or another appropriate acid to form the free acid sporanic or desacetoxycephalosporanic acid which is then extracted with an organic solvent such as ethyl The organic solvent extract containing the blocked amino acid derivative of or is adjusted to around pH with an alkaline material such as sodium tassium ammonium hydroxide or a suitable amine or other base containing the ammonium or cation as and is extracted with The water lution containing the blocked amino intermediate as the anion in the salt form is separated and evaporated to The residue is taken up in a minimum quantity of warm methanol and the desired product is precipitated by cooling optionally with isopropanol as an The talllne product obtained thereby is washed with tone and Before or after the intermediate product thus obtained can be treated in a conventional manner to remove the protective group from the aminoalkyl suitably by hydroge ation under mild conditions in the ence of a palladium or by exposure to mild acid ditlons for a short time formic acid at about room perature for about This intermediate product may also be treated with acid to remove the ing group and to form the trifluoroacetic acid salt of the sired or desacetoxycephalosporanic The acid salt group may be removed and the zwitterion form of the uct formed by treating this acid salt with any suitable anion exchange resin a base or acetate form by conventional Anion exchange resins suitable for this purpose include the weak anion exchange materials such as the resins sold der the trade names and in the acetate and the strong anionic exchange materials used for the removal of chloride and other anions from the cephalosporin solution exemplified by or a suitable organic amine anion change resin which may be used in preparing the compounds of this Invention include those marketed by Rohm and Haas der the trade names and and described Patent 2 anion exchange resin is a member of a family of high molecular weight liquid secondary water but readily soluble in hydrocarbons and other nonaqueous lite has a structural configuration ing of two highly branched aliphatic chains attached to the nitrogen a structure responsible for its excellent bility organic solvents and extremely low solubility aqueous These solubility together with the ability of secondary amines to react with acids to form the corresponding make the resin effective for the removal of acidic constituents from an aqueous Acylation of the or can also be carried out with an appropriate employed conjunction with a carbodilmide and the acylation proceeds at ordinary temperatures in such Any of the carbodiimidee are effective for this the active moiety being the Illustrative ples Include llylcarbodilmide phenyl and the other suitable carbodlimides being closed by Patent which Issued May the acylation of or can be carried out with an activated derivative of the selected suitably the ponding acid anhydride or a mixed anhydride or an activated ester such as the or cyanomethyl Some of these acid which as or in a form suitable for acylating or such as in the acyl halide mixed anhydride or haloformate contain asymmetric carbon atoms and thus may exist in optically active Isomeric These isomerlc compounds may be used as separated isomers or as ious stereolsomeric mixtures of the optical isomers to the compounds of this An example of mixed xt e c e e ed e e with mixtures of and acetic or the reactive variants or by mixing varying proportions of the separated and isomers of the acid compounds prepared as described in Examples 1 to 4 When the separate optical cephalosporin isomers are the selected acid starting materials can be resolved in a conventional manner such as by reacting the free acid with brucine or the then fractionally crystallizing the salts formed to separate the and then separately acidifying the separated isomer salts to liberate the desired optical or Each of the and thus can be employed as such for the or acylatlon with a carbodlimide or may be converted by methods into the ing acid mixed or haloformate acylating care being exercised to avoid extremes to conditions which might produce The invention will be more readily understood from the following operating which are submitted as lustrations and not by way of EXAMPLE 1 A mixture of of methyl chloro formate in 25 of acetone containing 2 drops of benzylamine was cooled an To the cooled thus of acid in 25 of acetone containing of trie lamine were added wise while stirring for minutes to form the mixed anhydride Then a mixture of of in 30 of water containing of triethylamine which mixture had been treated with charcoal and was added slowly while stirring over 5 The mixture was stirred in the cold for an additional hour to as plete a reaction as possible to form the blocked amino tamidoj cephaloeporan The above acid was purified by removing the washing the residue with cooling the mixture and into nonaqueous solvent by acidifying the mixture to pH with 1 N hydrochloric acid in the presence of ethyl No was observed to The solvent system was separated and the product in the ethyl acetate er was dried over magnesium After removal of the ethyl there was obtained percent of the desired as an amorphous which could not be made to crystallize The blocked amino acid derivative of was triturated with diisopropyl ether acid which analyzed as for Found C H N The of the compound was ultraviolet assay was ethyl EXAMPLE A portion of the cephalosporanic cold acid and stored in the cold for two hours to cleave the te oxycarbonyl blocking group and to form the trifluoroacetic acid salt of cephaloeporanic This salt was tated from solution by the addition of anhydrous ethyl ether in three The salt was separated from the liquids and washed in a centrifuge with ethyl ether and dried in a vacuum There was thus obtained 800 yield of the trifluoroacetic acid salt of aminoethylphenylacetamido7cephalosporanic acid which had values of and The ultraviolet spectrum in ethanol showed The trifluoroacetic acid salt of lJphen 500 millimole was dissolved in of water and stirred for 1 hour at room temperature in 20 of liquid percent berlite anionic exchange resin in the acetate form methyl isobutyl The aqueous phase was washed with methyl isobutyl ketone and then with ethyl The zwitterion product cephalosporanic acid precipitated upon concentration of the mixture in a vacuum but would not lize The weight of product recovered was 265 percent The infrared and ultraviolet spectra were The compound has a of and The compound had a specific rotation of trations against four clinical isolates of resistant Staphylococcus aureus of from to in the presence of human blood serum and from to in the absence of as compared with an MIC of to 9 for penicillin and to for a commercially available sodium as measured in this test by the This product had a median effective dose given orally of against Streptococcus pyoge strain in Against it had minimum concentrations by a standard gradient plate procedure as MIC Organisms Shigella 24 Escherichia coli 15 Escherichia coll l6 Klebsie la pneumoniae 10 Aerobacter aerogenes 10 Klebsiella pneumoniae Shigella EXAMPLE 3 Following the procedure of Example tert thyl sporanic acid was prepared by reacting te t chloride with After trituration of the compound in diisopropyl there was obtained of o hyl cephalosporanlc acid as which did not melt but decomposed at about The cipal ultraviolet reading at alcohol was in water it was The compound had a of and the infrared spectrum was consistent with this The product analyzed as Found 0 H N EXAMPLE ed as described in Example was dissolved in 10 of cold luoroacetic acid and stored the cold for 2 hours to feet cleavage of the blocking group and formation of the fluoroacetic acid salt of cephalosporanic The salt was precipitated from the solution by addition to the solution of three portions of anhydrous ethyl The precipitated salt was separated from the liquid washed on a centrifuge and dried in a vacuum The weight of the acetic acid salt of acid This salt had p values of and The ultraviolet spectral analysis was A portion of the luoroacetic acid salt of ic acid was dissolved in 10 of water and stirred for 1 hour at room temperature with 20 of liquid anionic exchanger in the acetate form in methyl isobutyl The aqueous phase was washed with methyl isobutyl and then with Concentration of the aqueous mixture until almost dry produced 275 percent two p values at and infrared spectrum was consistent with this The specific rotation of the compound was The product 4 aminos thyl acid had a minimum Inhibitory centration against clinical isolates of resistant aureus of to 1 in the presence of human blood and of to in the absence of as compared with an MIC of to 9 for penicillin G and to for a commercially used sodium as ed in this test by the This product had a median effective dose of given against Streptococcus strain C203 in mice Against organisms it had minimum concentrations as MIC Organism 24 10 11 7 4 750 Shigella I6 EXAMPLE A portion of acid was dissolved in a mixture of 30 of dioxane and 15 of To the resulting mixture there was added of trie thy lamlne of The mixture was cooled in an ice bath and then there was added dro wise over 20 minutes a solution of of chlorof ormate in 5 of dioxane while stirring the The mixture was stirred an additional 10 minutes at about to insure complete reaction to form the desired mixed To the cooled mixture there was added all at once a freshly prepared solution of of A and of in 20 of cold The mixture ed to stand at The mixture was concentrated under vacuum to remove some dioxane and and then luted with 30 of and washed with of ethyl The mixture was then layered with 200 of ethyl acetate and treated with 1 N hydrochloric acid to adjust the pH to while The layers were then the ethyl aoetate layer was washed with two portions of and the ethyl acetate layer containing the no product was layered over of water and the pH of the mixture was adjusted to pH with 1 N potassium hydroxide to form the potassium salt of in the aqueous phase was washed with 100 of ethyl and after separation of the aqueous phase from the ethyl the aqueous phase was dried under vacuum to leave the salt as a This salt residue was rified by dissolving it in 15 of warm filtering the resulting and then adding about 15 of propanol to crystallize the The salt crystals in the liquid mixture were cooled to filtered and then dried under There was obtained of the potassium The infrared spectrum was consistent with the named The ultraviolet ing was The was A portion of the above salt was dissolved in of water and then 15 of 98 percent formic acid was The mixture was stirred at for about The mixture was then concentrated under a vacuum to a gum which The pheny which resulted was only slightly soluble in hot or cold insoluble in ethyl and acetic but was soluble in formic The salt was suspended in 10 of water and treated with 1 N hydrochloric acid to pH 1 at which pH most of the solid The lution was the pH was readjusted to by the tion of N sodium A small amount of flocculent precipitate which was filtered The filtrate taining the sporanlc acid inner salt was about 20 The filtrate tion was concentrated to dryness under vacuum and tion The crystalline acid was washed with three portions of cold and filtered each The talllne product cephalosporanic acid had values of and in a thirds ormamlde in water The infrared trum was consistent for this The ultraviolet ing was The product aminome thyl acet acid had a minimum inhibitory concentration against four clinical isolates of esistant Staphylococcus aureus of in the presence of human blood serum and to 1 in the absence of measured by the The product had a median effective dose of m iven twice against Streptococcus pyogenes strain 0203 Against it had the following minimum inhibitory concentrations as measured by a gradient plate MIC Organism 36 10 8 5 4 5 Shigella sonnei 12 EXAMPLE 6 A mixture of 5 of of and of isobutyl chlorof ormate in 100 of tetrahydrofuran was made to form the blocked amino thyl yl7aoetyl isobutyl mixed To the resulting mixed while stirring and there was added a solution prepared by stirring of acid in 60 of and 60 of water while adding trie to a pH of The resulting reaction allowed to proceed to The intermediate butoxycarbonylamlnome desace sporanic acid was then isolated by the procedure desoribed in Example There was obtained of this product which had an ultraviolet reading of It had ues of and The compound was reprecipltated from ethyl ether and petroleum ether to obtain of a more pure material having an ultraviolet reading of with p values of and The portion of the intermediate product e oxyc t ny t acid was treated with 6 of fluoroacetic acid as described in Example to remove the blocking group from the moiety and to form the fluoroacetic acid salt of aminomethyl desacetoxycephalosporanic acid which was tated from solution by adding ethyl There was obtained of this salt The ultraviolet reading was values of and One of this trifluoroacetic acid salt was added to 2 of water and 2 of methyl isobutyl ketone in which mixture the salt was not Three milliliters of water were added and the resulting suspension was treated with the anionic exchange of Rohm and in the tate After stirring the mixture for about 1 hour to sure complete the precipitated solid was washed with methyl isobutyl and acetonitrile and yielding 390 of the desired thyl acid as the inner The infrared spectrum was consistent with this named The ultraviolet reading was The test showed one large The product had values of and This acid compound was rated effective as an oral antibiotic a test in given twice to a group of mice as described The value was of body weight as compared to an 0 value of In agar dilution tests against various this compound had 8 hour MIC values of less than milliliter against Streptococcus less crograms per milliliter against Escherichia coli This compound had MIC values against four different clinical lates of Staphylococcus aureus of from to 8 in the absence of human blood serum and from to 11 in the presence of humam blood insufficientOCRQuality

Claims (3)

1. Having now particularly described and ascertained the nature oi my said invention and in what manner the same is to be performed, H declare that what I claim is : - 1. An orally active cephalosporin antibiotic having the structural formula wherein R'is a hydrogen atom or an alkyl group having one or two carbon atoms and R1 is a hydrogen atom or an acetoxy group, an inner salt thereof, stereoisomeric mixtures thereof, or a salt thereof with a pharmaceutically acceptable acid or base.

2. Ί-^2ι- χ '-( AminomethylJphenyl acetamidoOephalo-sporanic acid.

3. 7-^2,- ' '-(dj-i^-A-ninoethylJpheny acetamldoj-cephalosporanio acid. _^2'-/£l l-^-^noethylJphenyl/acetamidoJ-cephalosporanic acid. 6. 7-^2' 1 -( Aminomethyl)phenyl7acetamido desace-toxycephalooporanlc acid. 7. A pharmaceutical composition which comprises a compound as claimed in any of claims 1 to 6 and a pharmaceutically acceptable exoipient. 8. A process for preparing an orally active cephalosporin antibiotic having the general structural formula wherein R is a hydrogen atom or an alfryl group having one or two carbon atoms and R 1 is a hydrogen atom or an acetoxy group , an inner salt thereof , stereoisomeric mixtures thereof , or a salt thereof with a pharmaceutically acceptable acid or base ; which comprises acylating 7-aminocephalosporanic acid or 7-aminodesacetoxycephalosporanlc acid or a water-soluble salt thereof with an acylating agent having at least one constitu-ent radical of the structure wherein RMis as defined above and, the amino group has a conventional protective group , and removing said protective group . 9 . The proce ss of claim 8 wherein the acylation is carried out in an aqueous medium or an organic solvent at a temperature between the freezing point of the reaction mixture and room temperature . 10. The proce ss of claim 8 or 9 wherein the acylation is carried out at a substantiall neutral pH. 11. The process of claim 8 , ^ i or 10 wherein the acylation is conducted at a temperature within the range of about 0 to 5°0. 12. The process of any of claims 8 to 11 wherein the acylating agent is a corresponding N-blocked 2- ' -(( -aminoallcyljphenyl acetlc acid moiety of the product by exposure to mild acid conditions for a short time . 21. The process of claim 20 wherein the product is exposed to the action of formic acid at about room temperature for about 1 to 5 hours. 22. The process of any of claims 8 to 18 wherein the protective group is removed from the amino group of the N-blocked 2- '-(c><-ejDainoalkyl)phenyl7acetic acid moiety of the product by treatment with trif luoroacetic acid with formation of the corresponding trif luoroacetic acid salt of the thus obtained 7-^2,-J+1 '-(aminoalltyDphenyl/acetamldo cephalosporan ic or desacetoxycephalosporanic acid product. 23. The process of claim 22 wherein the trifluoro-acetic acid salt of the 7-^2 ι - 1 ' - ( aminoalkyl Jphenyl/acet-amldo^oephaloBporanic or desace toxycephalosporanic acid product is treated with an anion exchange resin in base or acetate form to prepare the zwitterion form of said product . 2k. The process of any of claims 8 to 23 which comprises resolving an optically active 2-^ '- (i^ -amlnoalkyl )phenyl7-acetic acids starting material and employing the separated di-astereoisomeric acids or appropriate derivatives in the acyla-tlon . 25 . The process of claim 2½ where in a mixture of optically active 2-^¥' - ( ^-aminoalkyl )pheny ^acetic acids are re solved by reacting the free acids with cinohonine , strychnine , or bruclne , fractionally crystallizing the salts thus formed to separate the diaetereolsomeric salts , and then separately acidifying the separated diastereoieomeric salts to liberate the desired optical d- or 1- acid. 26. A process for preparing an orally active cephalosporin antibiotic having the general structural formula wherein R"is a hydrogen atom or an alkyl group having one to two carbon atoms and R 1 is a hydrogen atom or an acetoxy group substantially as hereinbefore described with particular reference to the examples . 27. Orally active cephalosporin antibio tics when produced by the process claimed in any of claims 8 to 26. 28. A pharmaceutical composition according to claim