CA1050010A - Process for preparing-3-methyl-4-(5-tetrazolyl)-a3-cephem compounds - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
6-Amino-2,2-dimethyl-3-(5-tetrazolyl)penam sulfoxides, 6-(N-protected amino)-2,2-dimethyl-3-(5-tetrazolyl)penam sulf-oxides and their direct conversion to 7-amino-3-methyl-4-(5-tetra-zolyl)-.DELTA.3-cephems and 7-(N-protected amino)-3-methyl-4-(5-tetra-zolyl)-.DELTA.3-cephems, useful antibacterial agents or intermediates for antibacterial agents, by heating under acid conditions, desirably in a liquid medium and especially one derived from a tertiary carboxamide, a tertiary urea derivative or a tertiary sulfonamide. The preparation of the tetrazolylpenam sulfoxide reactants is described.

Description

.

- - -' 10~0010 . . .

This in~ention relates to cephem compounds and manufacture thereo.
More particularly, it relates to 6-amino- and 6-(N-protected amino)-2,2-di- _ methyl-3-(S-tetrazolyl)penam sulfoxides and to a process for their direct conversion to 7-amino- and 7-(N-protected amino)-3-methyl-4-(5-tet-razolyl)-~3-cephems, a~class of compounds useful as antibiotics or as intermediates , ; therefor.
, :
The oxidation o~ 6-aminopenicillanic acid or a penicilli~, especially penicillin ester, to a sulfoxide ~as been Xnown for many years, , and a great variety of oxidizing agents have been used for their preparation.
Sykes et al., The Chemistry of Penicillin, H.T. Clarke et al., Ed., Princeton . .
Uhi~versity Press, Princeton, N;J. 1949, pp. 156, 927, 946, 1008; Chow et al;, J.
Org.~Chem. 27, 1381 (1965); Essery et al., J. Org. Chem. 30, ~388 (1965); Spry, J.
Or~. Chem. 37, 793 ~1972~; and U.S. Patent 3,275,626, issued September 27, 1966.

10500~0 The conversion of penicillin ester sulfoxides into desacetoxy cephalosporin esters by heating a penicillin ester sulfoxide under acid conditions, generally in a solvent or liquid medium at temperatures of from about 80C. to 175C. is described in a number of journal publi-cations and patents: Mor;n et al., J. Am. Chem. Soc. 91, 1401 (1969), Cooper et al., J. Am. Chem. Soc. 92, 2575 (1970), Cooper, J. Am. Chem.
Soc. 92, 5010 (1920); U.S. Patent 3,275,626; 3,591,585j 3,632,850, 3,647,787, 3,725,797; and 3,725,7990 The last two patents cited employ as acid catalysts salts or complexes of a nitrogen base having a pKb of not less than four with a mono- or di-substituted orthophosphoric acid or an organic sulfonic acid, respectively.
6-Amino-2,2-dimethyl-3-(5-tetrazolyl)penams (Pormula I) have been found to be valuable intermediates and/or antibacterial agents.
Such compounds and their preparation are described in Canadian Patent Application 211,057.
7-Acylamino-3-methyl-4-(5-tetrazolyl)- ~3-cephems and salt~
thereof are useful as antibacterial agents and as intermediates for pro-duction o~ antibacterial agents. Add;tionally, 7-amino-3~methyl-4-(5-tetrazolyl~ 3-cephems and certain 7-(substituted amino)-3-methyl-3-(5-tetrazolyl)-~3-cephems wherein the substitutent on the 7-amino group is other than an acyl moiety are also valuable intermediates leading to the preparation of 7-acylamino-3-substituted-4-(5-tetrazolyl)-~3-cephems~
Such compounds are described in ~anadian Patent Application 211,504.
The biological and non-biological uses of tetrazoles has recent-ly been reviewed by Benson, 'IHeterocycl~c Compounds", Elderf;eld, Ed., r ~ .
,i~ ~. .

~OSOO10 Vol. 8, John Wiley ~ Sons, Inc., New York, N.Y., 1967, Chapter 1 while a compilation of cephem references is noted in U.S. Patent 3,766,175 and ~,766,176.
According to the invention there is provided a process for preparing a 3-methyl-4-(5-tetrazolyl)-~3-cephem of the formula:

H H
R-NH~ ~/S~

wherein Y is selected from the group consisting of:
N N N - N
and N N N
Rl R2 wherein R2 is selected from the group cons;sting of hydrogen, alkanoyloxy-methyl having ~rom three to eight carbon atoms, l-alkanoyloxyethyl hav;ng from four to seven carbon atoms, methoxymethyl and phthalidyl, Rl is selected from the group consisting of R2 and -C ~ 7 ~; ~ R6 Ra wherein R6 is selected from the group consisting of hydrogen, alkyl ~; having from one to three carbon atoms and phenyl; R7 is selected from the group consisting of hydroxy, methoxy, alkanoyloxy having from two to four carbon atoms and benzyloxy; and R8 is selected from the group consisting of hydrogen, hydroxy, fluoro, chloro, bromo, iodo, methyl, methoxy, alkanoyloxy having from two to four carbon atoms, phenyl and benzyloxy or D !

., .. ,., . . , . ., , - . . . - . . . ~ - .. .

~OS~O10 x ~10 Rg wherein each of Rg and Rlo is selected from the group consisting of hydrogen and methyl; and X is selected from the ~roup consisting of oxygen and sulfur, R is selected from the group consisting of (a~ hydrogen, 2,2,2-trichloro-ethoxycarbonyl, 2,2,2-tribromoethoxycarbonyl, benzyloxybenzyl, (b) 2-phenylacetyl, 2-phenoxyacetyl, 2-amino-2-phenylacetyl, and (c) ~R3 R~

~ 5 wherein R3, R4 and R5 are each selected from the group consisting of hydrogen, chloro, bromo, fluoro, alkyl having from one to four carbon atoms, alkoxy having from one to four carbon atoms and pbenyl, characterized by heating a 6-amino or 6-substituted-amino-2,2-dimethyl-3-(5-tetrazolyl)penam sulfoxide of the formula:
H H
R-N~U3 in the presence of an acid reacting substance at a temperature of from 80C. to 175C. for a time suffic;ent to effect ccnversion thereof.

10500~0 As described and claimed in our copending divisional application the 6-amino or 6-substituted amino-2,2-dimethyl-3-(5-tetrazolyl)penam sulfoxide of the formula:
H H
R-N ~ ~ 3 ~J

where Y, R, Rl, R2, R3, R4, R5 are as defined a~ove, may be prepared by reacting the appropriate 6-amino or 6-(N-protected amino)-2,2-dimethyl-3-(5-tetrazolyl)-penam w;th an oxidizing agent, at a temperature of from 10C. to 30C. for a time suff;cient to effect conversion thereof.
The intermediate 6-amino or 6-substituted amino-2,2-dimethyl-3-tS-tetraæolyl)penam sulfoxides of the formula:
O -.
H H
R-N ~ H3 wherein Y is selected from the group consisting of;
N N ~ J
and ~ \
-N N ]
~1 ~2 wherein R2 is selected from the group consisting of hydrogen, alkanoyloxy-15 methyl having from three to eight carbon atoms, l-alkanoyloxyethyl having from four to se~en carbon atoms, methoxymethyl and phthalidyl, Rl is selected from the group cons;st;ng of R2 and tetrazolyl-penam nitroge~ protecting group; R is selected from the group consisting of (a~ ~ydrogen, 2,2,2-trichloroethoxycarbonyl, 2,2,2-tribromoethoxy-carbonyl, benzyloxybenzyl; (b) 2-phenylacetyl, 2-phenoxyacetyl, 2-amino-_5_ Dl .,,, ".i lOSOO10

2-phenylaaetyl, and ~c~
f 3 .

-[~

wherein R3, R4 and R5 are each ~elected from the group consisting of hydrogen, c~lo~c, ~ro~o, ~luoro, Alkyl hav;ng from one to four carbon . atoms, alkoxy ha~ing ~rom one to four carbon atoms and,pheny ~ e bel~e~ed to bo no~el.
The process of this in~ention is illustra~ed, in part, by the re~ct~on M H ~ H H
I R-N ~ ~ ~ R~

~ ~y ~ H3 wherein R ls selected ~rom the group consisting o~ hydrogen and amino protectlng group;
and Y 1J selected from the group consist~ng of .
and ~ ~

Rl ~2 wherein Rl is selected f~om the group consisting of R2 and tetrazolyl-cephem nit~ogen protect~ng group, the nature of which is defined below:

R2 is selected from the group consist;ng of hydrogen, ,~ t .... ...

lOSOO~O
alkanoyloxy~et~yl hA~in$ ~rom three to eight carbon atoms, l-alkanoyloxy-cth~l h~ng irom ~our to seven car~n atoms, methoxymethyl and phthalidyl.
Since the t~trazolylcephem nitrogen protecting group occurs in the pen~m co~pound of Formul~ I, Rl can also be defined as a tetrazolyl penam Ditrogen protectiDg group.
The term "amino-protec~i~g group" as used herein is intended to include any g~oup ~hich ~ll perm~t synthesis of compounds of ~ormula ~ under the conditions, e.g. of acidity and temperature, of this process and which c~n be removed under conditions wherein the ~-lactam ring re~ ins substantially intact. The nature o~ the amino-protecting greup is not critical to t~is invention. The R group is not involved in forma~
t~on o~ ~hc tetrazolyl moiety or in the ring enlargement reaction.
Its function is to protect the amino group, the penam and cephem ring sy~tems during the process descrlbed in detail below for format;on of co~pounds o~ F3~mula T~. It is subse~uently rcmo~ed at an Pppropr$~te point, gensrally at the ultimate or penult~mate step, o~ the process oP this i~ention at ~h~ch point its protective ~unction is no longer needed. rn ome i~stances, e.g., w~en ~ is triphenylmethyl or 9U~5ti-tuted tr~phenylmethyl it may be removed during the course o~ the pro-C~SB 0~ th~s inv~ion- However, sucb a group can be said to have ~ulfi~l~d ~ts protoct~ve ~unction; The selection and identif~cation of indiv~dual protectiDg ~roups is rèadily accomplished by one skilled in tho ~rt. The suitability and e~ecti~eness o~ a group as an amlno-protocting ~roup in this invention is slmply determ~ed by sub~ecting the 6-~N-protected-a~ino)-2,2-dimethyl-3-t5-tetrazolyl)penam sulfoxide (Fbrmula I) or desoxy precursor thereof wherein the protecting group is the group in question to the process of the instant invention. All such groups are to be considered within the scope of this invention~
In general, all groups known, or obvious, in the art as amino-protecting groups in pep~ide syntheses are operative in the process of n~
LYI

.........

105~0~0 this invention. Particular ~nte~es~ resides in the protecting groups enumerated belo~ beeause o~ their e~fec~iv~ness in protecting the 6-amino group and thei~ ea~e of remo~al ~ndar cond~tions wherein the ~ -lactam ring remains substantiallly intact n~mel~, 2,2,2-trihal~ethoxycarbonyl, (e.g. 2,2,2-trichloroe~hoxyoarbonyl, 2,2,2-tribromoethoxycarbonyl), benzyloxycarbonyl and triphenylmethyl ~tr~yl) groups, especially those of Formula ~ belo~:

wherein R3, R4 and R5 are each selected from the group consisting of hydrogen chloro, bromo, fluoro, alkyl having from one to four car~on atoms, alkoxy having from one to four carbon atoms, and phenyl.
When R of ~ormula I is hydrogen, the amino group becomes under the acid conditions of this process, an ammonium ion, and is thus protect-ed.
Additionally, in a broad sense 'tamino-protecting group" as use~
herein also embraces acyl moieties of organic carboxylic acids. The products of ~ormula II wherein R i8 acyl produced by the process of this invention are antibacterial agents per se or are readily converted to antibacter;al agents.
Thc term "tetrazolylcephem nitrogen protecting group" is intended, in the most general sense, to cover those groups which protect the tetrazole ring during or after formation thereof and during reaction of the so-protected tetrazolylcephem compound. A group can, therefore, .~

- . . .

~050010 be regarded as a tetrazolylcephem nitrogen protecting group when it (a) caD be attached to the tetrazolyl group during or after formation thereof;
(b) will permit the ring enlargement reaction of this invention even though it may be removed during said reaction; and (c) can then be removed from the tetrazolyl moiety without substantial degradation of the tetrazolylcephem ring system. Illustrative of such groups, in addition to those specifically enumerated herein as tetrazolylcephem nitrogen protecting groups are trialkylsilyl, triphenylmethyl and substituted triphenylmethyl groups.
The nature of the tetrazolylcephem nitrogen protecting group is Dot critical to this invention. It is ;ts abllity to perform a speci~c functiQn rather than its structure which is important. The selection and identification of appropriate protecting groups can read;ly and easily be made by one sk;lled ;n the art. The suitabil;ty and ef~ective-ness of a group as a tetrazolylcephem nitrogen protecting group in th~s invent;on are determined by employing a compound of Ebrmula I wherein Yl is the (Rl-substituted)-5-tetrazolyl-moiety in question as reactant in the here;n-described process for making -Formula II compounds. In view of this, it is obvious that the tetrazolylcephem nitrogen protecting group is also a tetrazolylpenam nitrogen protecting group. It, there-fore, becomes convenient to refer to Rl as a "tetrazolyL nitrogen protect-ing group'`.
As one skilled ;n the art w;ll recognize, the variables Rl and R2 when defined as alkanoyloxymethyl, 1-alkanoyloxyçthyl, methoxymethyl and phthalidyl are, in a sense, tetrazolyl nitrogen-protect~ng groups.
However, such groups, with the exception of methoxymethyl, cannot be removed without substa~tial degradation of the ~ -lactam ring and, thus, fail to meet the criteria set forth above for a "tetrazolyl nitrogen protecting group".
For the sake of convenience, the compounds described here~n ~re _g_ t :, lOS~O10 identified as derivatives of penam and cephem. The term "penam" has been defined in the J. Am. Chem, Soc. 75, 3293 (1953), as referring to the structure:
S

Penam Using this terminology, the well-known antibiotic penicillin G is desig-nated as 6-(2-phenylacetamido)-2,2-dimethyl~penam-3-carboxylic acid. The

3-tetrazolyl surrogate of penicillin G, Pormula I above wherein R is 2-phenylacetyl and Y is 5-tetrazolyl, is des;gnated as 6-(2-phenylacetamido)-2,2-dimethyl-3-(5-tetràzolyl)penam.
The term "cephem" has been defined in the J. Am. Chem. Soc.
84, 3400 (1962) as meaning the saturated structure:

7 ~ S ~ Cephem ~ 3 The term "cephem" refers to the same structure with a double bond, the position of wh;ch is ;ndicated by a prefixed "~" with super-script denating the carbon atom of lowest number to which the double bond is connected; e.g. ~3. Thus, the compound of Formula II wherein R is 2-phenylacetyl and Y is S-tetrazolyl is designated as 7-(2-phenylacet-amido)-3-methyl-4-~5-tetrazolyl)- ~3-cephem.
Many of the 5~substituted tetrazoles, as ;s known, can ex;st in two isomeric forms, viz:

N and / N ~N

- ~ S : 3l¦ ~N ~

As will be appreciated by one sk;lled in the art, when the substituent -lD-.
LP.~

-~soo~
represented by Rl or R2 is hydrogen, the two forms co-exist in a dynamic tautomeric, equilibrium mixture. However, in the case where Rl or R2 represent a substituent other than hydrogen, the two forms represent different chemical entities which do not spontaneously interconvert.
The present process is ~roadly applicable to a great Yariety - of precursors, e.g., desoxy compounds, of Pormula I reactants. Any com-pound of Formula I, or desoxy precursors thereof, the ~-lactam struc-ture thereof which is not substantially destroyed under the conditions of the process o~ this invention can be used as reactant in the conversion process described herein.
As Doted above, the R group of Pormula I can be hydrogen or an amino nitrogen protecting group, including an acyl group, which will protect the amino nitrogen and the ~-lactam ring to wh;ch it is attached from degradative attack under the conditions of acidity and temperature of this process.
Preferred amino protecting groups are 2,2,2-trichloroethoxy-carbonyl and 2,2,2-tribromoethoxycarbonyl. Such groups permit satisfac-tory conve~sion of the thus protected penamtetrazole compound of Formula I to the corresponding cephemtetrazole of Formula II and relat~vely easy removal of the amino protecting group. Further, the presence of such a protecting group is sometimes desirable as when the tetrazolylcephem nitrogen protecting group is one removable under acid conditions. These amino protecting groups are not removed under acid conditions alone and serve to protect the ~-lactam. They are subsequently rem~ved by a reductive deblocking step.
Especially preferred as amino protecting groups are acyl moieties of organic carboxylic acids and particularly those acyl moieties which correspond to or which are convertible to, the acyl moiety desired ln the tetrazolylcephem product. The 7-acyla~ino-3-methyl-4-t5-tetra-zolyl)- ~3-cephems thus obtained, if not antibacterial agents per se, ! ~ ~

105~010 are readily converted into antihacterial agents, as for example, by re-moval of the tetrazolylcephem nitrogen protecting group.
Particularly valuable acyl groups are those having the formula:
.

R ~ C ~ - IV
.~ .
_ l ~_ .~ n 5 wherein n is 0 or 1;
R' is selected f~om the group consisting of hydrogen, alkyl having from one to twelve carbon atoms, alkenyl ha~ing ~rom t~o to t~elve carbon atoms, cycloalkyl having from three to seven carbon atoms, cyclo-hexenyl, 1,4-cyclohexdienyl, l-amino-cycloalkyl having from four to seven carbon atoms, cyanomethyl, 5-methyl-3-phenyl-4-isoxazolyl, 5-methyl-3-(o-chlorophenyl)-4-isoxazolyl, 5-methyl-3-(2,6-dichlorophenyl)-4-iscx-azolyl, S-methyl-3-(2-chloro-6-fluorophenyl)-4-isoxazolyl, 2-alkoxy-1-naphthyl having from one to four carbon atoms in said alkoxy, phenyl, phenoxy, phenylthio, pyridylthio, benzyl, sydnonyl, thienyl, furyl, pyridyl, thiazolyl, isothiazolyl, pyrimidinyl, ~etrazolyl, triazolyl, imidazolyl, pyrazolyl, substituted phenyl, substituted phenoxy, sub8~
tuted phenylthio, substituted pyridylthio, substituted benzyl, subst1tuted thienyl, substituted furyl, substituted pyridyl, substituted thiazolyl, substituted isothiazolyl, substituted pyrimidinyl, substituted triazolyl, substituted tetrazolyl, subst;tuted imidazolyl and substituted pyrazolyl, each substituted moeity being substituted by up to two members selected ~rom the group consisting of fluoro, chloro, bromo, hydroxy, amino, N-alkylamino having from one to four carbon atoms, N,N-dialkylamino having from one to four carbon atoms in each of said alkyl groups, alkyl ha~ing from one to four carbon atoms, aminomethyl, alkoxy ha~ing f~om one to L~

., . . . , - . ' -.~ , ., . . ., .. , . ~ . , . ., . . ~ . ..

~050010 four carbon atoms, alkylthio having from one to four carbon atoms and 2-aminoethoxy.
Q is selected from the group consisting of hydrogen, alkyl having from one to six carbon atoms, hydroxy, azido, carboxy, sulfo, carbamoyl, phenoxycarbonyl, indanyloxycarbonyl, sulfoamino, aminomethyl, amino and NH-(CO-CH2-NH) -CO-Z;
m wherein Z ;s selected from the group consisting of alkyl having from one to six carbon at~ms, phenyl, sub~tituted phenyl, furyl, th;enyl, pyr;dyl, pyrrolyl, amino, N-alkylamino having from one to s~x carbon atoms, anilino, substituted anilino, guanidino, acylamino ha~ing from two to seven carbon atoms, benzamido, sub~tituted benzamido, thio-phenecarboxamido, furancarboxamido, pyridinecarboxamido, aminomethyl, guanidinomethyl, alkanecarboxamidinom~thyl ha~ing'from'three-to eight carbon atums, benzamidinomethyl, (substituted ~enz~midino)methyl, thio-lS phenecarboxamidinomethyl, furancarboxamidinomethyl, pyr~dinecarbox~mid~no-methyl, pyrrGlecarboxamidinomethyl and 2-benzim;dazolecarboxam~dinomethyl, each substituted mo;ety be;ng substituted by up to two members selected from the group cons;sting of fluoro, chloro, bromo, iodo~ alkyl having from one to four carbon atoms, alkoxy having from one to four carbon atoms, sulfamyl, carbamoyl and cyano;
and m is ~ or l;
provided that when R7 is l-aminocycloalkyl, n is 0, and p~ovided that when R7 is selected from the group con~ist~.ng o~ phenoxy, phenylthio, pyridylthio, subst;tuted phenoxy, subst~tuted phenylthio and s~b~tituted pyridylthio and n ;s 1, Q ;s selected ~rom the g~oup consisting of hydrogen, alkyl having from one to six carbon atoms, carboxy, sulfo, carbamoyl, phenoxycarbonyl, substituted phenoxy-carbonyl, ;ndanyloxycarbonyl and aminomethyl.
As one skilled in the art can readily appreciate, the 6~-carbon at~m of the antibacterial cephem side chain to which the amino or hydroxy, r ~ .
lL~

105~01~
~Q~ moiety is attached is an asymmetric carbon atom allowing for the ~: exi~tence of two optlcally act$ve isomers~ the D- and L-diastereoi~omer~, as well as the racemate, DL, form. In accord with previous findings concerning the act;vity of such cephems possessing asymmetric c~-car~on atoms, the compounds of the present invention po~se~sing the D-configura-t;on are more active than those of the L-configuration and are the prefer-red compounds, although the L and DL forms of the instant compounds are also considered within the purview of the present invention.
Of the aayl grOUp8 enumerated above, those where;n Rl ;s phenyl, ; 10 mono- or di~ubstituted phenyl and Q ~s hydrogen, hydroxy, amino, azido or carboxy represent a preferred class of derivatives.
Preferred tetrazolyl nitrogen protecting groups (Rl) are those having ~rmulae V and VI

~ 7 V

wherein ~6 iC hydrogen, alkyl having from one to three carbon atoms or phenyl; R7 ~ hydroxy, methoxy, alkanoyloxy havin~ ~rom two to four carbon atoms or benzyloxy and R8 i~ hydrogen, hydroxy, fluoro, chloro, bromo, iodo, methyl, methoxy, alkanoyloxy hav~ng from two to four carbon atom~, phenyl, or benzyloxy and ~ ~ 10 VI

wherein oach of R9 and Rlo iQ hydrogen or methyl and X i~ ~ulfur or oxygen. De~oxy compounds of F~mula I having such tetrazole nitrogen protecting g~oup~ are conveniently ~repared as Ss described by Barth, loc. cit. Further, such protectin~ groups are read~ly remcved from F3rmula II compo~nd~ w~thout substantial de~radatiQn of the ~-lactam ,t .. . . .

lOS~O10 ring.
Especially preferred as substituents (Rl and R2) on the tetra-zolyl mo;ety, particularly when R, the amino protecting group, is an acyl moiety, are hydrogen, alkanoyloxymethyl, alkanoyloxyethyl and phthalidyl.
S Such tetrazolyl cephems (~rmula II) produced by the conversion processof this invention are antibacterial agents E~ se.
The sulfoxide reactants of Formula I are prepared by treating the appropriate 6-amino- or 6-(N-protected aminn)-2,2-dSmethyl-3-t5-tetrazolyl)penam precursor with an oxidizing agent. The procedure com-pr~ses reacting the appropriate precurcor in a suitable reaction solvent with an oxidant; i.e. a sub~tance which prov~des active oxygen, such as hydrogen peroxide, per-acetic acid, perbenzoic, m-chloroperbenzoic acid, or any other organic per acid or a salt thereof; metaperiodic acid, iodo-sohenzene and ozone. The oxidant is used in an amount sufficient to provide about one atom of active oxygen per thiazolidine sulfur atom.
The reaction i~ generally conduated at ~emperatures of ~rom about lO~C.
to about 30C., and pr~ferably, for reasons o~ convenlence, at ~bout room temperature. The react~on temporaturo i8~ however, not critioal.
Suitable reaction-inert sol~ent~ whon each of Rl and R2 ~s hydrogen are water and aqueous organic sQlvents, especially mixtures of watar and organic sol~ents which are miJcible with water such as dioxane, j tetrahydrofuran, acetone and diethylenegly~ol dimethyl eth0r.
The sulfoxide~ are recovered by concentration of the solvent and precipitation o~ the prodùct from the concentrate, or by evaporation of the solvent and recry~tallization of the product.
When the substituents on the tetrazolyl moiety are other than hydrogen, ~uitable solvents are halogenated hydrocarbons e~pecially chlorinated hydrocarbons such as chloroform, methylene chloride, ethylene dichloride, ethylidene chloride~ chloro~enzene; aromatic hydrocarbons such as benzene, xylene, toluen~; ether~ such as dioxane, tetrahydrofuran, ,D 1 diethyleneglycol dimethyl ether; alkanoic acid amides such as N,N-dimethyl-formamide and N,N-dimethylacetamide.
The ~ul~oxide compounds of F~rmula I are then converted by the process of this invention to a corre~ponding 3-methyl-4-(5-tetrazolyl)- ~3-cephem compound of ~rmula II. The process compri~es heatin~ the appro-priate sulfoxide of Formula I, de~irably in a medium which is liquia at the temperature of the reaction, in the presence o~ an aci~ cataly~t;
i.e. under acl~ condition~, at from about 80C. to about 175C. until the conversion to the desired 3-methyl-4-(5-tetrazolyl)- ~ -cephem occurQ.
Repre~entative aaid catalyst~ are mineral aclds such a~ sulfur~c, hydrochloric, phosphoric aci~s; sulfon~c acids such as benzene~ul~onic acld, p-toluenesulfonic acit, naphthalenesulfonic acids, methanesul~onlc acid; or~anic acit anhydride~ such as acetic anhydride, propionic anhydride, benzoic anhydride; Lewis acids such aa aluminum chloride, bor~n tri~luoride, boron trichlorido, acyl chlorides ~uch a~ acetyl chloride, butyryl chloride, benzoyl chlorIdo; thionyl chlorIde, phos~ene, nitrosyl chloride.
Alternatively, and prcferably, in place of one of the aci~
catalysts enumeratad above, the conv~r~ion i~ accompli~hed by treating the appropriato ~ulfoxid of F~rmula I in th~ pre~ence o~ certa~n ac~d sdlt~ or compl-x~ a~ cataly~ts. The~e substance~, the ex~ct nature of which i~ not known, ccmprise the combin~tion of a ~trong acid and a weak organic baso. While any o~ the minoral acid~ dia¢losod abovo can be u~ed as the acid componont, ~avoro~ acid sub~tanco~ aro phosphoric ~cit and cor~a~n primary and ~econdary phoJphato~; i.e., mono- and die3ter~ o~
pho~phoric acid which aro strong di- and mcnoba~ic ac~d~, respoctlv~ly.
Repre~entati~e of auitable primary phQ~phates are tho~e wherein thc eater group ~8 an alkyl g~oup of from 1 tc 6 carb~n atoms; aralkyl uch as benzyl and phenethyl; aryl wherein aryl is phenyl and phenyl substituted with halo or nitro group~ such a~ 2-chloro-4-nitrophenyl, 4-nitrophenyl;

.

lOS~O10 and halo substituted alkyl such as 2,2,2-trichloroethyl.
Representative of secondary phosphate~ are diaryl esters wherein aryl is as defined above.
Phosphoric acid is the preferred acid because of its ava~labil~ty relative to that of the above-mentioned esters and the satisfactory yields which it affords.
The weak organic base component of the catalyst can be any nitrogenous base having a pKb greater than 4. As ~uch it can be a primary, secondary or tert;ary amine. Representative of ~uch bases are aniline, o-chloroaniline, m-methylaniline, o-methoxyaniline, p-hydroxyaniline, m-n;troan;l;ne, picolines, pyridine, lutidine~ quinoline, isoquinoline, N-methylan;line, benzimidazole, and others described in U.S. Patent 3,725,397. Tertiary amines are, in general fRvored, and heteroc~cl~c tertiary amines are preferred bases.
The ~alt tor complex) catalyst can be preformed or prepared in situ. It is generally more convenient to add the acid and ba~e components to the reaction ve~sel to permit formation of the catalyst in situ.
The amount of ac;d catalyst or the acid ~alt (or complex) catalyst system~ used is not critical but can vary widely. In general, amounts ranging from about 10% to about 20% by weight of the sulfoxide reactant are used. However, when the amino protecting group on the tetra-zolylpenam is hydrogen or a ba~ic substituted acyl g~oup (e.g., 2-amino-2-phenylacetyl), at lea~t an equivalent amount of acld is used. ~n s~ch instances, greater than one equivalent of acid i~ normally used, ~enerally from 1~ to 20% ~y weight in excess of the equimolar amount of acid.
The conversion can be conducted in the absence of a liquid medium but it is generally de~irable to use a reaction-inert medium which is liquid at the reaction temperature of the proce~ to moderate and fac~
tate the reaction. A wide variety of liquid media are thu~ available.
~0 The only criteria apart from that of ~eing inert under the conditions of the conversion process are sufficiently high enough boiling point to permit the use of temperatures of from about 80C. to about 175eC. and that it be liquid at this temperature range. Suitable media are aliphatic hydro-carbons, ketones, ethers, alkanoic acid anhyarides, and esters; aceto-nitrile, propionitrile and tertiary carboxamides. Representative of such media are alkane~ of 5 to 8 carbon atoms, benzene, toluene, xylene~, methylene chloride, carbon tetrachloride, 1,2-dichloroethane, methyl ethyl ~etone, methyl isobutyl ketone, ethyl acetate, acetic and propionic anhydrides, dioxane, tetrahydrof~ran, diethyleneglycol dimethyl ether, N,N-dialkyl formamides and acetamides especially tho~e wherein the alkyl - groups have from 1 to 5 carboD atoms, N-methyl-2-pyrrolidone, and o~er tertiary carboxamides such as enumerated in V.S. Patent 3,668,202. The tert~ary carboxamide~ can be u~ed as the liquid medium but are generally used in admixture with one of the other reaction-inert media enumerated above to optimize the yield of the ~3-cephem compound of Formula Il.
Further, tertiary urea derivatives and/or tertiary ~ul~nam~des which ~ulfill the criteria ~et forth above can also be used as the liqu~d media in this conversion process. Examples of such media are tetramethyl urea, tetraethyl urea, N,N-dimethylcarban;lide, 1,3-dimethyl-2-;m;dazol-idone, 1,3-dimethyl-2-hexahydropyrim;done, N,N-dialkylmethane sulfonamides wherein the alkyl groups have from 1 to 4 car~on atoms, and other ~uch compounds as are doscribed in U.S. Patent 3,647,787.
Still further, any water pre~ent, especially by-product water can, if desired, be removed by using a liquid media which permi~s effective removal o~ the water. This is accompli~hed by using a liquid ~hich ~orms an azeotropic system with water and permits its removal by azeotrop~c distillation or by using a llquid which reacts with water a~d permits ;ts inactivation and, hence, effective removal from the reaction zone.
Representative of liquids which permit azeotropic removal of water are benzene, carbon tetrachlorite, methyl ethyl katone, ethylacetate, hexane ~;''' 105~0~0 and other water-azeotrope forming liquids such as are set forth in Lange's Handbook of Chemistry, ninth edition (1956), pages 14B4~1486 and 1493, published by Handbook Publishers, Inc., Sandusky, Ohio.
Illustrative of the second category of liqu;ds; i.e., those which remove the water by chemical reaction are alkano;c acid anhydrides, sultones, and sulfonic acid esters. Examples of such chemical water in-act;vators are acetic and propionic anhydrides, p-toluenesulfonic acid anhydride, Cl-C4 e~ters of methane sulfonic, benzene and p-toluenesulfonic acids, propanesultone ànd butanesultone, and others as are taught in V.S~
Patent 3,591,585.
The above-mentioned liquids which effectively remove water can be used alone or in admixture with one or more of the reaction-;nert liquide enumer~ted above.
Alternatively, the by-product water is effectively removed through the u~e of molecular s;eYes as adsorbents for the water. Suit~ble ad~orbents are the natural and synthetic crystalline aluminosilicates.
The latter adsorbeDts are favored because of their greater water-loading capacity relati~e to the natural crystalline aluminosilicates. Included among such adsorbent~ are chabazite, gemlinite and analcite, natu~ally occurring material~, the ~ynthetic "Linde Molecular S~eves" produced and di~tributed by the Linde Company, such as Types 4A, 5A, and 13X, and the "Microtraps" produced by the Davison Chemical Company. Such materlals adsorb and thus effectively remove water from the reaction med~um. The molecular sieve ca~ be added directly to the reaction mixt~re or, prefer-ably, the water containing condensate from the reaction mixture ccntacted with such material to re ve the water. A further u~eful ad~orbent ie neutral activated alumina.
The conver~ion is conducted over the range of from about ~0C.
to about 175~C. and preferably from about 100C. to about 150C. ~or periods of from 1 to 24 hours. The lower temparature values requ;re more . ~ . .

time than do the higher temperatures. The convertion in general, is carried out at the lower rather than the higher values cited above.
~he products are i~olated by removal of the liquid med~a under reduced pressure and purification of the crude product thus obta;ned by recrystallization from an appropriate solvent, by chromatography over silica gel cellulose, silica-alumina and the like The 7-amino-3-methyl-4-(5-tetrazolyl-~3-cephem compounds o~
~rmula ~I are valuable intermediates for the preparation by acylation, ; of antib~cterial 7-acylamino-3-methyl-4-(5-tetrazolyl)-~3-cephems.
Certain of the 7-(N-protected amino)-3-methyl-4-(5-tetrazolyl)- ~3~
cephem compounds, i.e., those wherein the protecting group is other than an acyl group, also serve as intermediates for preparation o~ 7-acylamino-3-methyl-4-(5-tetrazolyl)-~3-cephems by procedures known to those skllled in the art.
The de~oxy precursors of F~rmula I compounds which serve a~
reactant~Sin the convers;on process of this invention are preparet ~rom the N-tr;phenylmethyl or N-(substituted)triphenylmethyl deri~atives o~
6-aminopen;cillanic acid by the reaction sequence discus~ed belDw.
In the fir~t step, 6-(triphenylmethylamino)penicillanic acid (Sheehan _ al. J. Am. Chem. Soc. 81, 5838, 1959) i~ converted ~nto an_ amide of Formula VII:
.

(C ~ 5)3NH ~ VII

wherein ~1 is phonyl, subatituted phenyl, furyl, ~ubsti~uted furyl, thienyl or 8ub~tituted thienyl, and W2 is hydrogen, alkyl, phènyl, sub~tituted phenyl, furyl, substituted furyl, thienyl, or substituted thienyl. Rl is phenyl or sub~tituted phenyl, and N2 is hydrogen, alkyl, phenyl or sub~t~-l~SOO~O
tuted phenyl, thi5 group can be removed by hydrogenoly~i~. This group can also be removed by solvolys~s in tr;fluoroacet;c acid, when the combined effect of ~1 ~nd W2 is sufficient to offer the requisite degree of stability to the incipient car~onium ion.

tCH

Particularly preferred configurations for this protecting group which afford satisfactory yields of desoxy precursors of Formula I are those o~
Formulae V and VI a~ove~
- The amide i5 prepared by activation of the 3-carboxy group o~
the 3-carboxy group of 6-(triphenylmethylamino)penicillanic acid, e.g.
by mixed anhydride formation, followed by reaction with an eq~imolar proport;on of am~ne of formula H2N-CHWlW2. Thus~ form tion o~ the ~xed anhydride involve~ react;ng an appropriate carboxyl~te ~alt o~ 6-tr~phenyl-methylam;nopenicillanic acid in a reaction-inert organic solvent, with approximately equimolar proportions of pivaloyl chloride or lower-alkyl chloroformate~. Appropriate salt~ are, for example, alkali metal ~alts, ~uch as sodium or pota~ium salt~, and amlne salt~, ~uch as triethyl-ammonium, pyridinium, N-ethylpiperidinium or N,N-dimethylanilinium salt~.
Appropriate ~olventY are~ tho~e which ~erve to dissolve at lea~t one o~
2D the reactant~, and the mixed anhydri~e product. Examples of ~uch ~ol-vent~ are chlorinated hydrocarbons, such a~ chloroform, methylene chloride; aromati~ hydrocarbons, such as benzene, toluene, and xylene;
and ether~, such a~ d~ethyl ether, tetrahydrofuran and 1,2-d~methoxy- -ethane. The reaction i~ u~ually carried out at a temperature in the range from about -50C. to about 30C., and preferably at about 0C.
The reacti~n commonly require~ about one hour. The product is isolated ~imply by fil*ering off the insoluble material~, and then e~aporating ~he ' L~

lOSOO~
solvent in vacuo to give the crude product. The latter can ~e uaed direct-ly, or purified further by methods known in the art. If de~ired, however, the mixed anhydride product need not be isolated. It can be used in ~itu for reaction with the amine simply by contacting the reactants in an inert solvent, for about 0.5 to about 2.0 hoursj at a temperature in the range from about -30C. to about 30C. and preferably at around 0~. The same ~olvents ident;f;ed above for m;xed anhydr;de formation are useful for the instant react;on.
In the ca~es wherein this reaction i~ conducted in a water-immi-o sc;ble solvent, the product is usually isolated by wathing the reaction mixture with water and then concentrating the organic solvent to dr~ness in vacuo, to give the crude product. The latter product can be u~ed immediately for Step 2, or, if desired, it can be purified further by ~ well-known method~. It ;5 sometimes convenient ~imply to wash the reaction ; 15 mixture with wate~, and then use the so-produced solution of amide direc~-ly in Step 2. In the cases where~n the reaction ~s conducted in a ~ater-miscible solvent, the product i~ usually i~olated by first removin~ the water-miscible ~olvent by evaporation in vacuo, replacing it by a water-;mmisc~ble solvent, and then proceeding as described above.
A~ will be obvious to one skilled in the art, other valuos o~
Rl which9 according to the criteria set forth here~n, are not tetrazolyl nitrogen protectin~ group~ can be introduced onto the carbamoyl group of 6-triphenylmethylaminopenicillanic acid i~ like manner. This includes such value~ as alkanoyloxymethyl, l-alkanoxyloxyethyl and phthalidyl.
In Step 2, the product from Step 1, or a a~mple t~An~ormat~on product thereof in which any phenolic hydroxy groups are protected by conversion to formyloxy, alkanoyloxy or alkoxymethyl groups, is converted inta an imidoyl chloride by reactlng the ~ai~ amide in a reaction-inert or~anic ~olvent with phoageRe and a tertiary amine. About one molar equivalent of pho~gene i~ uaually used, but amount~ up to about two or l~.

three molar equivalents are sometime~ employed. The tertiary amine is preferably preseDt in an amount equal to or greater than the amount of phosgene. The reaction i5 carried out at a temperature in ~he range from about -20C. to about 30~C., and preferably at about 25C., and it usually requires a few hours to reach completion. A variety of ter~iary amines can be used in this process, for example trimethylamine, tr;ethyl-amine, N,N-dimethylaniline, U-methylmorpholine and pyr;d;ne, and the l~ke.
Typical solvents which can be used are chlorinated hydrocarbon~ such as chloroform, methylene chloride and 1,2-dichloroethane, and ethers such a~
tetrahydrofuran, and 1,2-dimethoxyethane. If desired, the imidoyl chlorlde can be isolated by evaporation of the filtered reaction mixture, but in many instance~ it is convenient to use the imino chloride in ~itu.
Several other reagent , for example, thionyl chloride or a phosphorous halide ~uch as phosphorous pentachloride are operative ~n the imidoyl chloride forming reaction. Moreover, ;f desired, u~e can be made of the corresponding imidoyl bromide.
In Step 3 of the sequence, the above lmidoyl chlor~de ~s con~er~-ed into a tetrazolylpenam compound of ~ormula 6 5 3 ~ ~ ~___-CH3 VIII

~ N
/~
Nl~H

where~n -CHNlW2 is as pre~iou~ly defined. This transformation comprises treating the said imidoyl chloride in a reaction-inert solvent with about one molar equivale~t, or ~ometimes a small exce~, of azlde ion. The ~ -23-~i '.
~ , , ~

10500~0 reaction mixture is then stored at or about ambient te~peratures for several hours, for example, overnight, until conversion into tetrazole $s substant~ally complete. A wide variety of azide ion sources are operative in this proce~, and examples of those which are particularly valuable are S trialkylsilyl azides having from one to four carbon atom~ in each of said alkyl groups, ~uch as trimethylsilyl azide and triethylsilyl azide, metal ~alt~ of hydrazoic acid, such as potassium and sodium azide, t~ibut~l-ammonium azide, N,N-dimethylanilinium azide, N-methylmorpholinlum azid~
and pyridinium azide, tetramethylguanidinium azide. Appropriate ~olvent~
in cases wherein the az;de ion source is a trialkylsilyl azide or a trl-substituted ammonium azide are chlorinated hydrocarbon solvents, ~uch a~
chloroform, methylene chloride and 1,2-dichloroethane. Dipolar aprotic ~olvent~ such a~ N-methylpyrrolidone, can al~o be used. In reaction~
where a metal ~alt of hydrazoic acid con~titute~ the azide ion ~ource the~e dipolar aprotic ~olvent~ become the ~olvent-type of choice. Product i~ola-tion i~ achieved u~ing ~tandard methods. When a low boiling chlo~lnated~
hydrocar~on i~ the ~ol~ent, the reaction solution is washed with dilute alkali and then the organ;c solvent ls evaporated off. ~hen a dipolar aprotic solvent i~ the sQlvent the reaction mixture is usually flr~t di-luted with a large excess of dilute alkali, and then, after appropriate adjustment of the pH, the product i3 isolated by solvent extraction.
When a ~ub~tituted triphenylmethyl group (Formula I~) i3 de~rod as the amino-protecting groupt the appropriate 6-t ub~tituted triphenyl-methylamino~penicillanio acid i~ readily prepared ~y alkylation of 6-amino-penicillanic acid with the appropriate substituted triphenylmethyl chloride (or ~romide).
The procedure comprises react;ng 6-aminopenlcilla~ic acid ~n chloroform or methylene chlor;de solut;on wi~h the approprsate RCl or RBr and an equivalent a unt of an acid acceptor. The reaction i~ initially conducted at about 0-5C. for 0.5 to 2.0 hours and then at ambient tempera-~ -23a-ni L~,~,j'' ~osoo~o ture for up to 72 hours. The product, if desired, is i~olated by standard procedures (e.g. evaporation of solvent).
When 2,2,2-trichloro(or tribromo)ethoxycarbonyl a~ benzyloxy-carbonyl are de~ired as amino-protecting groups the appropriate 6-substi-tuted aminopenicillanic acids are prepared by reaction of 6-aminopenic~l-lanic acid with 2,2,2-trichloro(or tribromo)ethylchloroformate or benzyl-oxychloroformate ln a reaction-;nert solvent such as dioxane ~t about -20C. to ~25C. ~n a Schotten-BaumaDn reaction.
The N-triphenylmethyl derivatives thus obtained are con~erted to desoxy compounds of Formula I (R=H) by treatment of the triphenylmethyl derivative with acid. A wide variety of acidic reagent~ such as methane-~ulfonic acid benzenesulfonic acid or p-toluenesulfon~c acid, an anhydr~ue hydrohalic acid; such as hydrogen chloride or hydrogen bromidej an alkanolc acid, such as acetic, propionic, chloroacetic or trifluoro acetic acid, and the l;ke can be u~ed. The reaction i~ normally carried out by di~ol~ing the starting material in an appropriate solvent and adding about two molar equ;valent~ of the acid reagent, at or about ambient temperatureO
Reaction i~ complete within about one hour, and the product is present in the react;on medium in the form of the acid-addition -23b-~ . ;

' ~ 1050010 `', salt corrcsponding to the acid reagent used. A solvent should be cSosen which ; will dissolve the starting penam and examples of solvent~ which find use are:
ethers, such as diethyl ether, tetrahydrofuran, dioxane and 1,2-dimetho~yethane;
: chlorinated hydrocarbons, such as chlorofor~, methylene chloride a~d 1,2-di-chlor~ethane; lower aliphatic ketones, such as acetone, methyl ethyl ketcne . - .. and methyl isobutyl ketone; esters, such as e,thyl acetate and butyl acetate;
bydrocarbons, such as hexane, cylcohexane and benzene; and lower alkanols, such as methanol, ethanol, and buta~ol. Although it is common to use about two ~olar equival~ts of acid in this process, only one molar equivalent is necessa~
when either the reaction is carried out in the presence of oDe molar equivalent of water, or the acid is introduced as a monohydrate. A favored procedure com-prises the use of ~-toluenesulfonic acid in ac~tone since the p-toluenesulfon-. ate salt of the protuct often psecipitates.
The 2,2,2-tr~chloro (or bromo~ethoxycarbonyl protecting groups are removed using acetic acid-zinc dl~st, formic acid-zinc dust or a zinc-copper ; couple in form~c acid diluted with acetonitrile in the manner described by Çhauvette ct .~1. J. Org. Chem. 36, 1259-67 ~1971). The benzyloxycarb~nyl pro-tecting ~roup is remo~ed by tr~atmeDt of the so-protected compount with a mix-tlJre of trifluoroncetie acid/anisole (4:1, v/v) and trifluoromethylsulfonic aci .
~ 20 lt ls advantageous that this procèdure be conducted at ice-bath temperaturcs ~
; (about 0C.) and for a limited period of time, usually for four to six minutes.
If higher temperaturos, e.g., 25-40C., are used, or longer reaction times, cuch as 1-3 hours, simultaneous re~oval of the tetrazole nitrogen proteding ~roup is possible. ?his may, of course, be desirable in certain instances such 25 as when a compound of formuln Il carri~s benzyloxycarbonyl as amino prot~cting group and a tetrazolylcephem nitrogen protecting group of for~ula V or Vl.
Precursor compounds of formula I wherein R is an organic acyl moiety, . are prepared by acyla~on of the apprcpriate 6-amino-2,2-dimethyl-3-[5-tetra-zolyl)penam with an activated derivative of a carboxylic acid, such as an acid :' . ' ' .
, '' . ' .
: ,- .

11 105~010 - '. I
¦chlor~de, a mixed anhydride, an activated ester (e.g., p-nitrophenyl) or the : ¦reactive intermediate formed by ~he acid and dicyclohexylcarbodiimide or ether . ¦peptide bond forming reagent. A typical acylation procedure comprises reactin~
¦the compound in a reaction inert solvent, e.g. methylene chloride, chloroform, ¦tetrahydrofuran, ethyl acetate, butyl aoetate, acetone, methyl ethyl ketone lor N,N-dimethylformamide, with an equimolar a~ount of an a~propriate ~cid chloride; and preferably o~ phenacetyl ch~oridP or phenoxyacetyl chtoride, at ¦a temperature of from about -40~C. to about 30C. and preferably from about ¦-10C. to about 10C. The protuct i5 isolated ~y standard metnods as by eva-1 ¦poration of the reaction mixture to dryness and treat~ent of the re~idue withla water-im~isci~le solvent and water, The acylated product if insoluble, is ¦filtered off otllerw1se the pH of the aqueous phase is adjusted to an appro-¦ priate value and the phase containin~ the product separated and evaporaCed.
I I~ like ~anner, form~la II compounds wherein R is hydorgen are acylate .
1 Tbe metho~s described above for rem~ving amino-protecting groups fro~
¦ 6-(protected amino)-2,2-dimethyl-3-(5-tetrazolyl)pcnams, pJecurSors of for- .
¦ mul~ I compounds, also apply to remo~al of s~ch groups f rom compounds of ¦ formula II. ~ -¦ 5he eetrazolylccphcm nitrogen protecting group of compounds of for-2 mula 11 is r~moved in the manner described above and comprises contac~ing the compounds with trifluoroacetic acid acid/anisole ~e 30-50C. for sev~ral hours.
Alternatively, when Rl or ~2 is alkanoyloxymethyl, l-alkanoyloxyethy , phthalidyl or methoxymethyl, such groups can be introduced into compounds of 2 formula II or precursor descxy compounds Or formula I (Rl, R2=~) by alkylatio~
of thc tetrazolyl moiety with an appropriate alkylating a~ent; an alkanoyloxy ~ethyl halide or l-alkanoyloxycthyl hal~de (Ul~ch et ~1 , J. Am. Chem. Soc. 43 . 660, 1921 and Euranto et al., Acta Chcm. Scand. 20, 1273, 1966), phthalidyl halide or chloromethyl methyl ether.
'.' . , .
~ - 25 -' ' . ' ' .
. .
. , . .

,,, , . ;. , - .

10500~0 The phthalidyl. alkanoyloxymethyL and l-(al~noyloxy3ethyl substitut~
tetrazoles of the final products are pro-drug forms of the final products, and although inactive or of relatively low activity against micro organisms E~ se are metabolized to the free tetrazole (Rl=H) when iniected parenterally ~o an~
animal, including man. The rate of metabolic conversion of the compounds ~o the free tetrazole occurs at such a rate as to proYide an effective and pro-longed concentration of the free tetrazole in the animal body. In effect, such compounds ~ct as depot sources for the free tetrazole antibacterial agent.
The tetrazolyl cephems described herein wherein the substituent on the tetrazolyl moiety is R2 exhibit in vitro activity agains~ a variety of mlcro-organisms, including both gram-positive and gram-negative bacteria.
The~r useful activity can readily be demonstrated by in vitro test~ against various organisms in a brain-heart infusion medium by the usual two-fold serial dilution techni~lue. The in vitro activity of the herein described compo~nds renders them useful for topical application in the form of ointm~nts, creams, and the like, or for sterilization purposes, e.g., sick-room utensils. .
They are also effective ant1bacterial agents in vivo in animals including man, not only via the parenteral route of administration b~t also ~y the oral route of administration.
Obviously, the physician will uitimatcly determine the dosage which .
will be most suitable for a particular individual person, ~nd it will vary wi~h the age, weight, and response of the particular patient as well as wlth the nature and extent of the symptoms, the nature of the bacterial infection being treated and the pharmacodyna~ic characteristics of tbe particular agent to be dministered. It will often be fou~d that when the composition is administered rally, lar~er quantities of the active ingredient will be required to produce the same level a~ produced by a smaller quantity adminis~cred parenterally.
: Having f~ll regard for the ~oregoing factors it is considered that a~
ffect~ve daily oral dose of the compoun~s of the present invention in humans f approximately 50-1,000 mg.Jkg. per day, wlth a preferred range of about 250-750;mg./kg. per day, i~:single or divided doses, and a parenteral dose of 25-500 m~./k~. p~r da-~, with a preferred ran~c of about 125-400 ~l IkL;- per day wil¦

` ~ '1050010 ,' ' I
¦ef~ectively alleYiate the symptoms of the infection. These values are illus-¦trative, and there may, o~ ccurse, be individ~al cases where higher or lower ¦dose ranges a~e warranted.
- ¦ The tetrazolylce~hems of for~ula II wherein the substituent on the ¦ tetrazolyl ~oiety is R2 are remarkably eEfective ln treating a number of inEec-tions caused by susceptible gram-negative and gram-positive b-~cteria in poultry ¦and animals including man. For such purposes, the pure r~terials or mixtu~es ¦thereo with other antibiotics can be employed, They may bc administered alone or in combination with a pharmaceuti'cal carrier on the ~asis of the chosen route 10 ¦of administration and standard pharmaceutical practice. For example? they may . I be administered orally in the form of tablets containing such excipients as ¦starch, milk sugar, cert~in types of clay, etc., or in capsules alone or in ¦ ad~ixture with tlle same or equivalent cxcipients, They may also be administere I orally ~n the form of elixirs or oral suspensions which may contain flavoring or coloring agents, or be injected parenterally, that is, intramusc~larly or ~ubcutaneously. For parenteral adm~nistration, they are best used in the orm o~ a sterile ~queous solution which ~ay be either aqueous such as water, iso-tonic sallne, isotonic ~xtrose, Ringer's ~lution or non-aqueolls such as fatty oils of vege~able origin tcotton seed, peanut oil, corn, sesame) and other non-aqueous vehicles which will not interfere with the therape~tic efficienty ofthe preparation and are nontoxic in the volume or proportion used ~glycerol, propylene glycol, sorbitol). Additionally, compositions suitable for extem-poraneous p~eparation of solutioDs prior to administration may advantageously be made. Such compositions may include liquid diluents, for example propylene giycol, diethyl carbonate, glycerol, sorbitol, e~c.; buffering agents, as well as local anesthetics and inorganic salts to afford desirable pharmacological properties. ' ' -~ Illustrative examples of the process of this invention and representa ¦¦tlve prepa tionK for =~kin~ ehe necess-ry searting =aeeri~ls are provided.

, ~ , . ,, . - , .

- - . .''~i _ .. .~. .

`- 1050010 ............................... I
. EXAMPLE 1 . ' ' . '.. .' ' '-~
. 7-~2-phenyl~cetamido-3-~lethvl-4-(2-~PivaloYloxYmethYltetrazol-5-y~ 3 cephe .'. . , . ~ . I
A.) 6-(2-phenylacetamido)-2,2-dimethyl-3-(2-lpivaloyloxymethyl~tet-razol 5-yl)penam sulfoxide -S To a solution of 6-(2-phenylacetamido)-2,2-dimethyl-3-(2-Zpivaloyloxy-m~Thy~
tetrazol-5-yl)penam (472 mg.~ 1.0 ~mole) in methylene chloride (15 ml.).is added m-chloroperbenzoic acid ~2~3 mg., 1.0 mmole and the mixture stirred at room temperature for forty minutes. The reaction mixture is transferred to a separ~tory funnel and washed twice ~ith dilute aqueous sodium bicarbonate, once with distilled water and once with saturated brine. It is then dried over anhydr~us ~agnesium sulfate and th~ solv~nt removed under reduced pressure. Th white ~oamy rèsidue to ta~en up in methy~ene chloride (2S ml.) in a round-. bottomed fl~sk and the solution boiled on a steam b~th. A9 the methylenechlôride is boiled of~ it is replaced by hcxane so as to maintain a constant volume. This ~s continued untll the solution bec~mes cloudy. It is then cooled, stirred, and tlle walls of the flask scratched to induce crystallization The precipitate is granul~ted for 1.5 hours and then recovered by filtration, : washed with hexane and air dr~ed. Yield ~ 233 mg., (47.8%) as white crystals;
.~. 139.5-140.5C.
B.) Conversion of A to corresponding A3-cephcm A Soxhlet app~r~tus is flame dried, placed under a positive nitrogen atmosphere and charged with sulfoxide (123 mg. 0.25 mmole) prepared in A above and anhydrouq dioxane (20 ml., distilled from LiAlH4). Pyridine (3 drops) is added to the colorless solution, followed by phosphoric acid (1 drop of 85X).
A white precipitate is formed. The reaction mixture is stirred and heated to gentle reElux and the condensàte passed into a thimble filled with an adsorbent : comprising a l-l mixture of alumina and Linde Molec~lar Sieve Type 4A (avail-able from the Linde-Co~pany~. ~he white precipitate d~ssolved after a few min-utes of heating, leaving a slightly cloudy solutio~l. The reaction m~xtuse ~s rcfluxed for a total of l~ hours and is then ev~pornted under reduced pressure-The yellow, oily residu~ i8 taken up in methylene chloride (25 ml.) and water , - 28 -1 ~0500~0 : `
. ~25 ml.), thoroughly mixed and washed successively with 10 ml. each of dilute . ¦hydrochloric acid, dilute sodium b~carbonate solution, water and saturated . ¦br~ne. The methylene chloride solution is dried (MgS04) and evaporated to `;'`'~ . ''' .' . " ' ' : ' ` ' ' '''- ' ' ' .
' ` ' ' `' ' ,, . .' ''' .' ' . , .

~ ~ lQSOO10 The procedure of Example 1 is repeated but using the appropriate 6~
protected amino)-2,2-dimethyl-3-(5-tetrazolyl~penams of formula I t~ produce correspondin~ a3~cephe~s of formula ll. (~he dotted lines represent unsatura-S tion, only one of which can be prese~t.).

ll R-: ~3 R~

¦ ~ g~C~

~ . R Ro phenylaceta~tido l-tpiv~loyloxymethyl) phenylacet.~mido l-(p-methoxyb~nzyl) triphenylmethyl l-(p-~ethoxybenzyl) phenylacetnmido l-~p-b~nzyiwxy~enzyl) .
. triphenyln~ethyl l-(o-methoxybenzyl) phenylaccta~ido l-tacetoxym~t3lyl) , triphenyl~ethyl l-(m-methoxybenzyl) . -~ ~ rphenylacetamido 2-(n-butyryloxymetl)yl) ; . . phenylaccta~ido l-(p-ltydroxybenzyl) tripl-enyl~le~hyl l-(p-~cetoxybenzyl phenoxyacetami~o l-(p-methoxyben~yl) triphenylmethyl l-(p-butyryloxybe;tzyl phenoxyacetamido l-(pivalnyloxymctllyl3triphenylmethyl l-(o-acetoxybenzyl) pheno~:yncet~ ido 2-(pivnloyloxyme~hyl) triphenylmethyl -Sp-benzyloxybenzyl) ' phenoxyncetamido 1-(2-furylmcthyl) triphenylmethyl l-f~r~uryl pheno~vacetamido l-(p-hydroxybenzyl) tripheny~methyl 1-(3-furylmethyl) phenoxyacett~ldo 2 (~cetoxymethyl) triphenylmethyl l-(p-hydroxybenzyl) phen~x~acctamido l--(p-benzyl~xybenzyl) ttriphenylmethyl l-(o-hydroxybenzyl) phenoxy~cetamido l-(p-acetoxybeitzyl) tr~henylmethyl H phenoxyacetamido l~
. . '. . ' : '. .' .
. . ~ ~ 30 -., ,, - .

,............... .,, ,, ~ . .
. . ' ~ , ' ' 105~

7-(2-Pheny]acetamido)-3-Methyl-4-~l-Lp-Methoxybenzyl~tetrazol-5-yl~3-cephem A solution of 6-(2-phenylacetamido)2,2-dimethyl-3-(1-tp-methoxybenzyl~
~etrazol-5-yl)penam sulfoxide (478 mg., 1.0 mmole) and p~toluenesuLfonic ac.d (50 mg.) in xylene (20 ml.) is heated at reflux for five hours and then evaporated to dryness under reduced pressure. The residue is taken up in methylene chlo-ride (25 ml.) and water (25 ml.), thoroughly mixed and washed successively with 10 ml. each of dilute hydrochloric acid~ dilute sodium bicarb,~nate solution~
water and saturated brine. The methylene chloride solution is dried (MgS04) and evaporated under reduced pressure to'give the~title compound.

, ' , ' --' - ' -' :'~

105001~ `
E~MPLE 4 7_Amino-3-Methyl-4-(L-~p-Methoxybenæyl3tetrazoL-5-vl)-~ -Cephe~

A. 6-A~ino-2,2-dimethyl-3~ Lp-methoxybenzyl~tetrazol-5-yl)penam sulfoxide Ozone is bubbled into a slurry of 6-amino-2,2-dimethyl-3-~ p-methoxy-benzyl~tetrazol-5-yl)penam (1.80 g., 0.005 mole) in methylene chloride (100 ml.) at 5C. for three hours. Lyophilization of the reaction mixture affords the sulfoxide.
B. Conversion of A to correspondin~ ~ -Cephem A mixture of the sulfoxite from A above (0.376 g., 0.005 mole), pheny-dihydrogen phosphate (0.174 g.~ 0.001 mole) and pyridine (0.091 g., 0.001 mole in d~oxane (50 ml. of anhydrous, peroxide-free) is refluxed for eight hours and the condensation passed through a column of neutral activated alum$na before being returned to the reaction flask. The reaction mixture is evapora-ted to dryness in vacuo and the residue taken up in methylene chloride (50 ml.) adn water (50 ml.) and thorough.y mlxed. The mixture is washed succes~ively with dilute aqueous sodium b$carbonate (20 ml.), water tl x 20 ml.) and saturated brine. The methylene chloride solution is dried (MgS04) and eva-porated under reduced pressure to gi~è the desired product.

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, 1050010 ! ~ ~
~hen the above-procedures are repeated, but the 6-amino-2,2-dimethyl- 9 - 3~ p-methoxyben~ylltetrazol-5-yl)penam used therein replaced by an equimolar . amount of the appropriate 6-amino-2,2-dimethyl-3-(substituted)tetrazol-5-yl) :. - penam, there is produced the following Lompounds; .
,~,. iL 1-~

. R ~ Ro . trityl l-(p-methoxybenzyl) trityl l-urfuryl .
.: lo H ~ -acetoxybenzyl) l-(p-hydroxyben~yl) . H l-t~-hy~roxybenzyl) .
. . ~ (p-benzyloxyben7.yl) . ~ 2-~pivaloyloxymethyl) . . 15 phenylacetamido . l-(acetoxymethyl) -. . phenylacetamido l-(p-benzyloxybenzyl) .
. p~lenylacetamido l-methoxymethyl I : lOSOOlV
¦ EX~MPLE 5 ¦ 7-~2-Phenylacetamido)-3-~cthyl-4-(5-Tetrazolyl)-a3-Ce~hem ¦ A. 6-(2-Phenylacetamido)-2,2-dimethyl-3-(5-te~razolyl)penam sulfoxide ¦ A solution of 5.3 g., 0.0148 mole) 6-(2-phenylacetamido-2,2-dimethyl-5 1 3-(5-tetrazolyl)penam acetic acid (15 ml ) and 30% hydro~en peroxide (3 ml.) is ¦ stirred at room temperature for 90 ~inutes. The reaction mixture is diluted to 200 ml. wi~h water to gi~Je a cloudy solution which is filtered through dia~oma~
¦ ceous e~rth. The thus obtained clear aqueous solution is freeze-dried to furn-ish an amorphou~ solid which is cxtracted with dichloromethane. Insoluble matte ¦ is filt~red. The dichloromethane solution is evaporated under reduced pressure;
¦the residue ;s slurried in diethyl ether, filtered, and the filtrate evaporated to give the title compound: Yi~ld = 1.6 gm. (29%) ir (KBr) 1784, 1675 em 1;
nmr (D20-NaHC03) 7.35 ppm (s, 5H), 6.00 (d, lH), 5.5~5.3 (~, 2i~), 3.65 (s, 2H), 1.60 (s, 3H0, 0.80 (s, 3H). ~
B. The pro~uct of procedure A above is converted to thc title ~3-= C~ y ~h p-o~u~e ~ ~a~

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~050010 PREPARATION-A
.
6-(Triphcnyll7ethylamino)-2,2-dimethyl-3-(l-t4-methoxybenzyl,~
tetrazol-5-yl)penam (A). 6-(Triphenylmethylamino)-2,2 dimethyl ~ N-C4-methoxybenzyl3c~rbam~yl)-penam.
To a stirred slurry of 86.4 g. ~0.8 mole) of 6-aminopenicillanic acid in 600 ml. of anhydrous chloroform is added 11.2 ml. (0.4 mole) of triethyl-amine~ and the mixture is stirred at ambient tenperature until a clear sol~-tion is obtained (ca. 15 minutes). To this solution is then added, portion-wise over about 25 minutes, 134.9 ~D (0.44 mole)~ of 90% pure triphenylmethy~
chloride, at ambient temeprature. Stirring is continued for a further 64 hours, and then 5.6 ml. of triethylamine is added. The solution is cooled to 0-5 C.~ and then an ice-cola solution of 38 1. (0.4 mole) of ethyl chloro-formate in 80 ml. of chloroform is added dropwise during 30 min~tes with the reaction temperature being maintained between 4 and 9 C. After a f~rther lS
minutes of stirring, 52.4 ml. (0.4 mole) of 4-methoxybenzylamine is injected into tbe reaction medium, below the surface of the sol~ent, at 4 to 9 C., and over a period of 30 min~tes. Stirring is continusd for a further 30 minutes at 3 to 6 C.~ for 20 minutes while thé reaction medium warms to 20C. The reaction mixture is then washed with water, .ollowed by brine. Finally, it is -dried us~ng magnesium sulfate to give a chlorofonm solution of 6-(triphenyl-methylamino)-2~2-dimethyl-3-(N~4-methylbenzyl]carbamoyl)penam.

~B~ 6-(Triphenylmethylamino)-2,2-dimethyl-3-~1-4-methoxybenzyl~tetrazol-S-yl)penam.
To a chloro~orm solution containing 69.4 g. (0.120 mole) of 6-(tri-phenylmethylamino)-2~2~.dimethyl-3-(N-~4-emthoxybenzyl~carbamoyl)penam~

;

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_35~

- ~ ~050010 '~

and having a volu~e of 133.3 ml.. prepared by the method described in (A) above, ~s added a further 132.7 ml. of chlorofor~, followed by 29.1 Dl. ~0.36Q
: mole) of pyrid~ne. This solution is cooled to 10 C., a~d then 26.22 ~.
(0.126 mole) pf phosphorus perltachloride is added during 15 minutes, with stir-S ring. Stirring is continued at ca. lOD C. for 10 minutes, and then at ambien~
te~Sperature for a furt~.er l.S hours, giving a solution of the i~ino chloride To a one-ssixth aliquot of this imino chloride solution is added 4.85 ml.
(0.060 mole) of pyr~dine, followed by 2.42 ml. (0.060 le) of metnanol at ca.
25 C., with st~rring. Ater a further 15 mlnutes of stirring 2.03 g. ~0,03 ~0 mole) of ammoDium chloride, followed by 2.59 g ~0.039 ~ole) of 95Z pure . sodiu~ azide, is added. The reaction mixtùre is then stirred at ambient ; tempera~ure for a further 4 hours. At th~s Point, 400 ml. of water and 200 ~1.
of chloroform are added, and t~en the layers are separated. ~c organic phase is washed with water, dried using magnesium sulfate, and then concencra-_ __. .
ted to a small volume in vacuo. This final chlorofor~ solution is added ~ropwise with stirring to a large volu~e of di~sopropylether, and, after 30 ~inutes, the precipit~te which has formed is filtered off. ~s afords 6.1 g. of 6-(triphenylmethylamino)-2,2-dimethyl-3~ S-methoxybenzyliteLraz~l-S-yl)penam. The infrared spectrum of the protuct (KBr disc~ shows an a~sorpcion 20- band at 1790 cm 1 ~-lactam); and the hllR spectrum (in CDC13) shows absorptions at 7.25 ppm ~multiplet, aromatic hydrogens), 5.40 ppm (broad singlet, benzyl hydrogens~, 5.05 ppm (singlet, C-3 hydrogen), 4.50-4.30 ppm (multiplet, C-S
an~ C-6 hydrogens), 3.70 ppm (singlet, me~hoxy hydrogens), 3.50-3.10 ppm tbroad peak, NH), 1.50 ppm (singlet, C-2 methyl hy~roge~s) and 0.7S pp 2S ~ lnglet C-2 _ ~l hydrogens~

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I . . ~OSO~
REPARATI0~-3~

6-~triphenylmethylamino)-2.2-dimethyl-3-. . I . tl-t4-benzylox~fbenzyl3tetrazol-5-yl)penam '. .'', ,:., I ,, ., ., ' ' "' '~ ' .
;. .'I 6-(Triphenylmethylamino)-2 2-dimethyl-3-(N-4-benzyloxybenzyl3carba-S ¦ r~oyl3penam ~ To a stirred solution of 20.0 g. o~ 6-triphenylmethylaminn-pen-~clllanic acid (Sheehan and Henery-Logan, Journal of the American Chem cal . ¦ Societv, 8I, 5836 .tI959~) in 140 ml. of acetone, at 0-SC., is atded 6.08 ml.
of triethyla~ine followed by 5.78 ml. of isobutyl chlorofor~ate. ~fter a fur-I ~her 10 ~inutes, t~e mixture is filtered directly into a st~rred solution of ) l~ 9.28 g. of 4-benzyloxyben~yla~ine ~n l,OOQ ~1. of water and 3~ m~. of acetone j at.ambienc te~perature. She mixture so obt~ine~ is stirred for 4 minutes, and i then a~ adtit~onal S00 ml. of water is added. Stirring is contin~ed for a fur-ther 7 minutes, and then the reaction ~ix~ure is eYtracted with etner. The ether is dried using anhydrous ~agnesium sulfaLe, and then evaporated to dry-¦ ness in vac~o. The crude product so ob~ained is re-d~ssolved in 200 nl. of ; - etber, whlch is then adted dropwise over 10 minutes to 2,500 ml. of hexane.
. ~he solid which precipitates is filtered off, gi~in~ 21.5 g. of 6-(triphenyl-methylamino)-2,2-dimethyl-3-(N-~4-benzyloxybenzyl~carba~oyl)penam.
. ~ 6-~Tr~phcnylmethylamino~-2,2-dimethyl-3-(chloro-[N-(4-benzyloxy-benzyl)i~ino~methyl)penam To a stirred solution of 2.0 g. of the above-described amlde in 10 ml. of try chloroform, at 0-5C., i~ added 0.9~ ~1. of pyridine, followed by S.42 ml. of a 2.26 M solution of phosgene in chloroEor~.
The reaction mixture is thçn stirred at ambient te~perature overnight. At this point, it is evaporated to dryness in vacuo, yielding a;viscous gu3, which 25 ~ is extracted with 100 ml~ of ether. The eth~r is filtered, ind evaporation of ~: ; ¦~thc ffltr e affords the ~1DO chlorlde _ a yellou foa~

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6-(Triphenylmethylamino?-2,2-di~ethyl-3-tl-~4-be;lzyloxybenzyl~-tetrazol-5-yl)penam - The abcve-describ~d i~inv chloride is rP-dissolved in ; . 8 ml. of dry ~ imethylf~rmamide. To this solutio~ is added~249 mg. oE
. potassium azide, and the turbid solution is stirred at acbient te~perature for S 2.25 hours. The solvent is evaporated at a~bient temperature, under high .
vacuum, leaving a brown gum. ~his residue ~s partitioned between 60 ~1. of . water and 150 ~1. of e~her. The ether phase is separa~ed off, washed with : saturated brine, dried using anhydrous sotium sulfate, a~d fir.all~ evaporated to dryne-~s ~n vacuo. The resitue is 980 mg. ~f 6-(triphenylmetnylahino)-2,2-d~methyl-3-(1-t4-benzyl~xybenzyl]tetrazol-5-yl:pena~. Its ~DR spectrum (in CDC13) shows absorptioD bands at 7.30 ppm (multip7et, aro~atic hyd~ogens), 5.45 ppm (quartet, benzyl hydrogens3, S.OS ppm (singlet, C-3 hydrogen), 5.0D
~ppm~~ng~C, ~e~gl-hydrogens), 4.40 ppm (mult~plec, C-5 and C-6 hydrogens)~ . .
1.40 pp~ ~lnglet, C-2 hydrogen) and 0.70 ppm ~singlet, C-2 hydroge~.

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PREPARATION C
~ .
6-(Triphenylmethylamino)-2,2-dimethyl-3-(1-furfuryltetrazol--5-Yl ~penam (A) 6-(triphenylmethylamino)-2,2-dimethyl-3-(N-furfurylcarbamoyl)penam, To a stirred slurry of 216 g. (1 mole) of 6-aminopenicillanic acid in 1500 ml. of chloroform, is added, at 25-30C.~ 278 ml. (2 mole) of triethylamine.
To the solution thus obtained is added, portionwise during 25 minutes, 306 g.
(I.l-~ol~ of triphenylmethyl chloride, at 25-30C. Stirring is then continued for 44 hours at ambient temperature.
A 522-ml. portion (0.25 mole) of the abo~e 6-(triphenylmethylamino)-penicillanic acid solution is cooled to 4C., and then 3.5 ml. of triethylamine is added. With vigorous stirrin~ is then added 23.75 ml. of ethyl chloroforn~ate at 5-10 C. Stirring is continued for a further 30 minutes at ca. 6C. at the end of the addition, and the ô,43 ml. of furfurylamine is in~ected into the reaction medium below the surface of the solvent. At 10 minutes intervals, three further portions of furfurylamine (5.90 ml., 4.22 ml. and 3.54 ml.) are then in~ected into the reaction medium in similar fashion. The total volume of fur-furylsmine added in 22.09 ml. (0.25 mole), and the temperature is maintained at ca. 6C. throughout the addition of the amine. When the addition of the amine is complete, the cooling bath is removed and the reaction medium is stirred at ca. 25 C. for 45 minutes. It is then washed successively with three portions of;water, and one portion of brine. Finally, it is dried using anhydrous magnesium sulfate. This affords 610 ml. of a chloroform solution of 6-(triphenyl-methylamino)-2~2-dimethyl-3_(N-furfurylcarbamoyl penam. The NMR spectrum of this solution showed absorptions at 7.3 ppm (17H, m)~ 6.2 ppm ~lH~ m), 4.35 ppm ~3H, m)~ 4.05 ppm (2H, s), 1.6 ppm (3H~ s) and 1.35 ~3H~ s~.

10500~0 (B) 6-(triphenylmethylamino)-2,2-dimethyl-3~ furfuryltetrazol-5-yl)penam.

- To a stirred solution of 3.05 g. (5.7 mmole) of 6-(triphenylmethyl-amino)-2,2-dimethyl-3-(N-furfurylcarbamoyl)penam~ in 8 ml. of chloroform, at 0 C., is added 1.35 ml. (17 mmole) of pyridin, followed by 2.64 ml. of a 4.33 M solution of phosgene in chloroform. Stirring is then continued for 1 hour at 25C. The chloroform, and excess phosgene and pyridine, are then removed by evaporation in vacuo~ and the residue is redissolved in S ml. of chloroform. The solution is cooled to 0CO~ and then 2.25 g. (14.4 mmole~ of tetramethylguani-dinium azide is added in several small portions. Stirring 15 continued for 15 ~inutes at ambient temperature~ and then 20 ml. of chloroform~ followed by 30 ml. of water, are added and the pH is adiusted to 6.5- The chloroform layer is separated off~ washed with water~ followed by brine, and then dried (MgS04).
Removal of the solvent by evaporation in vacuo leaves 3.37 g. of a dark-red foam. ~-The foam is re-dissolved in a small volume of chloroform and absorbed onto a column of chromatographic silica gel. Elut~on of the column with chloroform~
followed by evaporation of the appropr~ate fractions in vacuo, affords 6-(tri-phenylmethylamino)-2,2-dimethyl-3-(1-furfuryltetrazol-5-yl)penam. The MMR
spectrum of the product ~CDC13) shows absorptions a~ 7.40 ppm (m, 16H), 6.40 ppm (m~ 2H)~ 5.50 ppm (s, 2H)~ 5.2~ ppm (s, lH), 4.90 ppm (m, 2H), 1.60 ppm (s~ 3H)~ and 0.80 ppm (s, 3H).

- ~40~ -' .~ ".

~05001`0 PREPARATION D
.
6-(Triphenylmethylamino)-2,2-dimethyl-3-(1-~5-methyl-_ furfurylJtetrazol-5-yl)penam : The title compound is prepared according to the procedure of Preparation C, but using 5-methylfurfurylamine in place of furfurylamine. The NMR spectrum (CDC13) of the product shows absorptions at 7.36 ppm (m, 15H), 6.33 ppm (m, lH)~
5.93 ppm ~m, lH~ 5.50 ppm (s, 2H)J 5.20 ppm (s, lH), 4.50 ppm (m~ 2H)~ 3.23 ppm (d~ lH)~ 2.26 ppm (s, 3H)~ 1.63 ppm (s, 3H) and 0.90 ppm (m, 3H).

PREPARATION E

6-~Triphenyl~ethylamino)-2,2-dimethyl-3-(1-~2,4-dimetho~ybenzyl3-_ tetrazol-5-yl)penam _ _ -The title compound is prepared in 46% overall yield from 6-(triphenyl-methylamino)penicillanic acid~ by replacing the furfurylamine of Preparation C 2;4 dimethoxy~enzylamine. The crude product is purified by recrystallization from mixture of methylene chloride and methanol. The NMR spectrum of the product (CDC13? sho~s absorptions at 7,40 ppm (m, 16H), 6.45 ppm (m,-2H)~ 5.40 ppm (s, 2H)~ 4.50 ppm ~m~ 2H), 3.75 ppm (s, 3H), 3.70 ppm (s~ 3H)~ 1.55 ppm (s~ 3~) and O.90 (s~ 3H).

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' . :
,.

10500~0 The procedure of Preparation P is repeated~ except that the furfurylamine is replaced by an equimolar amount of the appropriate amine~ to produce the following congeners:

~ GH3 ( 6 5)3 NH ~ \ 3 \ N
18 ~ N

\ CH

- 4 R17 R4 Rl7 R18 3 H20. H H
3_Cl 4-CH30 H
CH3 4-CH30 . H
3 C6H5 , 3 ~ -3_Br H 6 5 4_F 6 5 H H H

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. ' ' ~osoo~o PREPARAT ON G

6-(Triphenylmethylamino)-2,2-dimethyl-3-(1-~4-hydroxybenzyl]-tetrazol 5~vl)Denam (A) 6-(Triphenylmethylamino)-2,2-dimethyl_3-(N-~4-hydroxybenzyl3carbamoyl)-penam.
To a stirred slurry of 43.2 g. (0.20 mole) of 6-aminopenicillanic acid in 300 ml. of chloroform is added 55.6 ml. (0 .40 mole) of triethylamine, followed by 61.2 8. (0.22 mole) of triphenylmethyl chloride, at ambient temperature. Stirring is then~continued for a further 48 hours at ambient temperaeure.
A 120-ml. portion (containing 0.060 mole of triethylamm~nium 6-triphenylmethylamino penicillanate) of the above chloroform solution is with-drawn. It is diluted with a further 40 ml. of chloroform, and then 1.67 ml.
(0.012 mole) of triethylamine is added. The mixture is cooled to ca. 4 C., in an ice-bath, and then 6.84 ml. of ethyl chloroformate is added all at once, with stirring. Stirring is continued for 30 minutes with ice-bath cooling~ and then 7.5 g. (0.060 mole) of 4-hydroxyben~ylamine is added. Stirring is con-tinued for 10 minutes with ice-bath cooling, and then for a further 1 hour without cooling. At this point~ the chloroform solution is washed with water~
followed by brine~ and then dried using anhydrous sodium sulfate. Removal of the solrent by evaporation in vacuo affords the crude amid~ me crude amide is re dissolved in 5d ml. of chloroform and absorbed on a column of chromato-graphic grade silica gel. Theecolumn is eluted with chloroform, taking 400 ml.
fractions. Fractions 9 to 15 are combined and concentrated to an oil, which solidi~ies on trituxatlon with methylene chloride. After further trituration ~43-' ' ' ~0~0010 with ether; there is obtained 12.63 g. of 6-(triphenylmethylamino)~2J2-dimethyl~
3-(N-~4-hydroxybenzyl~carbamoyl)penam~ m.p. 166-168 C. (dec.). The infrared spectrum of the product (CHC13 solution) shows absorptions at 1785 cm I (8-lactam) and 1675 cm 1 (amide I). The NMR spectrum of the product ~CDC13) shows absorptions at 7.60-6.40 ppm (multiplet, 20H, aromatic hydrogens and amide hydrogen), 4.70-4.10 ppm (multiplet, 5H, C-5 and C-6 hydrogens, benzyl methyl-ene hydrogens and C-3 hydrogen), 2.98 ppm (doublet, lH, amine nitrogen), 1.64 ppm (singlet, 3H~ C-2 methyl hydrogens) and 1.31 ppm (singlet, 3H, C-2 methyl hydrogens~. -(B) 6-~Triphenylmethylamino)-2,2-dime~hyl-3-(1-L4-hydroxybenzyl~tetrazol-

-5-yl)penam.
To'a stirred solution of 1.69 g. (3 m mole) of 6-(triphenylmethyl-amino)-2~2-dimethyl_3_(N_~4_hydroxybenzyl3carbamoyl)penam (prepared as des-cribed in A) in 9 ml. of chloroform is added 1 ml. (12 mmole) of pyridine.
The solutino is cooled to ca. 4 C. in an ice-bath and 0,ôO ml. of chlorotri-methylsilane is added. The solution is stirred for 40 minutes at ambient temperature, and then it is again cooled to ca. 4 C. Phosgene (1.5 ml. of a 4.3M solution in chloroform (6.45 mmole) is added and the cooling bath is removed. S~irring is continued for a further 1.5 hours, and then all the volgtile components are removed by evaporatlon in vacuo.
The oily residue is redissolved in 6 ml. of chlorofor~ and the solu-tion is cooled to ca. 4 C. in an ice~bath. To the stirred solution is added 0.95 g. (6 m~ole) of tetramethylguanidinium azide, and then stirring is con-tinued for a further 1 hour at ambient temperature. At this pointJ 25 ml. of water is added~ followed by sufficient 1 N s~dium hydroxide to bring the pH of ' lOSOOlC~
the aqueous phase to 10. The chloroform layer is separated off~ washed with water, dried using sodium sulfate, nnd evaporated to dryness in vacuo. The oily residue (2.3 g.) is dissolved in a small volume of chlorofo~m and absorbed on a column of 30 g. of chromatographic silica gel. The column is eluted with chloroform, taking 50-ml. fractions. Fractions 13 tc 19 are combined and con-centrated in vacuo to ~ive 0.71 g. of 6-(triphenylmethylamino)-2,2-dimethyl-3-(l-E4-hydroxybenzyl~ etrazol-5-yl)penam, The infrared spectrum of the product (in CHCI3) shows an absorption at 1780 cm l ~ -lactam). The NMR spectrum (CDC13) shows absorptions at 7.80-6.67 ppm (multiplet~ 20H~ aromatic hydrogens 10 and phenolic hydrogen), 5.66-5.10 ppm (quartet~2H~ benzyl methylene hydrogens), 5.02 ppm (singlet, lH, C-3 hydrogen), 4.60-4.20 ppm (multiplet~ 2H, C-5 and C-6 hydrogen), 3.10 ppm (doublet, IK, amine hydrogen~, 1.44 ppm (singlet, 3H, C-2 methyl hydrogens)-and 0.71 ppm (singlet~ 3H~ C-2 methyl hydrogens).

_45_ 10500~0 PREPARATION H

6-(Triphenylmethylamino)-2~2-dimethyl-3~ 4-acetoxybenzyl~-tetrazol-5 vl)Denam To a stirred solution of 1.69 g. (3 mmole) of 6-(trlphenylmethyl-amino)-2,2-dimethyl-3-(N-C4-hydroxybenzyl~carbamoyl)penam in 9 ml. of chloro-form is added I ml. (12 mmole) of pyridine. The solution is cooled to ca.
4 C. in an-ice-bath and 235 mg. of acetyl chloride is-added slowly. The solution is stirred for 2 hours at ambient temperature, and then it is again cooled to ca. 4 C. Phosgene (1.5 ml. of a 4.3 M solution in chloroform L6.45 mmole~) is added and the coolin~ bath is removed. Stirring is contin~ed for a further 1.5 hours, and then all the volatile components are removed by evaporation in vacuo. The residue is redissolved in 6 ml~ of chloroform and the solution is cooled to _ . 4 C. in an ice-bath. To the stirred solution is added 0.95 g. (6 mmole) of tetramethylguanidinium az,ide, and then stirring is continued for a further 1 hour at ambient temperature. At this point~ 25 ml. of water is added~ followed by sufficient lN sodium hydroxide to ~ring the pH of ~he aqueous phase to 10. Theechloroform layer is separated off, washed lw1th water~ ~ried using sodium sulfate~ and evaporated~to dryness in vacuo.
This affords crude 6-(triphenylmethylamino)-2~2-dimethyl-3~ 4-acetoxybenzyl~- -tetrazol-5.yl)penam, which is purified further by chromatography.
When the above procedure is repeated, except that the acetyl chlorlde is replaced by an equimolar amount of formic-acetic anhytride and chloromethyl methyl ether, respectively~ the product is 6-(triphenylmethylamino)-2,2-dimethyl-3-(1-~4-formyloxybenzyl]tetrazol-5-yl)penam and 6'~triphenylmethylamino) -2~2-timethyl-3-(1 ~ (methoxymethoxy)benzyl3tetrazol-5-yl~enam~ respectively. -~
,.~' ::-_46-~OSOO10 PREPARATION I

6-Amino-2~2-dimethyl-3~ 4-methoxybenzylJtetrazol-S-yl)~ena~ p-toluenesulfonate To a stirred slurry of 143 g. of 6-(triphenylmethylamin~)-2,2-di-methyl-3-(1-L4_methoxybenzyl~tetrazol-5-yl)penam in 1~000 ml. of dry acetone is added 45.0 g. of ~-toluenesulfonic acid monohydrate, at ambient tempera-ture. The solids slowly dissolve~ giving a clear solution. After about 15 minutes, the product starts to precipitate. Stirring is continued for a further 45 minutes af~er the product starts to appear, and then a first crop of product is filtered off and washed with chloroform. The acetone is evapo-rated to dryness, and the solid residue is slurried for 45 minutes in 300 ml.
of chloroform. This affords a second crop of product. The two crops are com-bined~ slurrièd for 1 hour in l,OOO ml. of chloroform~ filtered off~ and dried in ~acuo giving 123 g. of 6-amino-2,2-dimethyl-3~ 4-mebhoxybenzyl~tetrazol-S-yl)penam P-toluenesulfonate, m.p. 174-175.5C. The infrared spectrum (KBr disc) of the product shows an absorption band at 1795 cm 1, The NNR spectrum (in DMSO-d6) shows absorption bands at 7.20 ppm (multiplet~ arom~tic hydrogens), 5.80 ppm (multiplet, benzyl hyd~ogens~ C-5 hydrogen and C-8 hydrogens), 5.20 ppm (doublet, C-6 ~ydrogen)~ ~.75 ppm (slngletJ methoxy hydrogens, 2.35 ppm (singlet, sulfonate methyl hydrogens), 1.70 ppm (singlet, C-2 methyl hydrogens) and 0.85 ppm (singlet~ C-2 methyl hydrogens).

~O~O~lO
PREPA~ATION J
Reaction of the appropriate 6-(triphenylmethylamino)-2,2-dimethyl-3-(l-substituted tetrazol-S-yl)penam with p-toluenesulfonic acid monohydrate, sub-stantially according to the procedure of Preparation I provides the following pounds as their ~-toluenesulfonate salts:
Compound Yield 6-amino-2~2-dimethy1-3-(1-~4- 79 benzyloxybenzy~ tetrazol-5-yl)-penam 6-amino-2,2-dimethyl~3~(1-fur- 62 furyltetrazol-5-yl)penam 6-amino-2~2-dimethyl-3-(1-L5- 54 methylfurfuryl]tetrazol-5-yl) penam 6-amino-2~2-dimethyl-3-(1-~2~4- 99 dimethoxybenzyl~tetrazol-5-yl)penam To a stirred solution of 304 mg. of 6-amino-2,2-dimethyl-3-(1- 4-benzyloxybenzyl tetrazol-5-yl)penam E~toluenesulfonate in 10 ml. of methylene chloride is added 69.7 ~1 of triethylamine. After 3 minutes~ 5 ml. of water are added and the mixture is stirred vigorously. The organic phase is then remo~ed, diluted with ether, dried using anhydrous magnesium sulfate, and eva~
porated to dryness in vacuo. The residue is 189 mg. (86% 'yield) of 6-amino-2, 2-dimethyl-3-(1~ 4_benzyloxybenzyl -tetrazol-5-yl)penam ree base.

:' 105~0~0 PREPARATION K
6-Amino-2 2~dimethyl-3-(5-tetrazolyl~p-en-am A stirred solution of 32.0 g. of 6-amino-2,2-dimethyl-3-(1-~4-methoxybenzyl~tetrazal-5-yl)penam p-toluenesulfonate9 and 24 ml. of anisole, in 96 ml. of trifluoroacetic acid is maintained at 40 + 1 C. for 35 minutes.
The trifluoroacetic acid is then removed rapidly by vacuum distillation. A
120-ml. portion of ether is added to the residue, which produces a white floc-culent suspension. The suspension and solvent is cooled to about 0 C.~ and to it is then added~ pcrtionwise~ 80 ml. of 2N sodium hydroxideS giYing two clear phases. The pH of the aqueous phase at this point is about 2.7. The layers are separated, and the ether phase is discarded. The pH of the aqueous phase is raised to 4.1 with 2N sodium hydroxide. This aqueous phase is then washed wi~h 100 ml. of et~er and filteréd. It is combined with the cor-responding aqueous phases fr~m four other identical experiments, and the total aqueous solution is ~yophilized to gi~e crude 6-amino-2,2-dimethyl-3-(5-tetrazolyl)penam. This crude product is slurried in a small amount of water and filteret off. It is then re~suspended in water and brought into solution by raising the pH to 7.4 by the addition of sodium hydroxide solution. The clear solution is extractéd with ether and the extracts are discarded. The pH of the aqueous phase is ad~usted to 4.1 using dilute hydrochloric acid~
and the product which precipi~ates is filtered off. The infrared spectrum of the product shows an absorption at 1795 cm 1. Its NMR spectrum (in DMS0-d6) shows absorptions at 5.65 ppm (doublet C-5 hydrogen~ 5.20 ppm (singlet, C-3 hydrogen), 4.70 ppm (doublet~ C-6 hydrogeD), 1.65 ppm (singlet, C-2 methyl hydrogens) and 1.10 ppm (singlet~ C-2 methyl hydrogens).
When each of the 6-amino-2~2-dime~hyl-3-(1-substituted tetrazol-5-yl) penam ~-toluen~sulfonate salts described in Preparation J is treated wi~h trifluôro-ace~ic acid/a~isble? according to the above procedure, the product in each case is 6-amino-2~2-dimethyl-3~5~tetrazolyl)penam.

-49~

: .:

~OSO~LO
PREPARATION L

6-(Triphenylmethylamino)-2 2-dimethyl-3-(5-tetrazolYl)Denam 7_ -To a stirred solution of 1.69 g. (3 m mole) of 6-(triphenylmethyl-amino)-2,2-dimethyl-3-(N_~4-hydroxybenzyl~penam prepared as described in (Pre-paration G) in 9 ml. of chloroform is added 1 ml. (12 mmole) of pyridine.
The solution $s cooled to ca 4 C. in an ice-bath and 0.80 ml. of chlorotri~
methylsilane is added. The solution is stirred for 40 minutes at ambient -temperature, and then it is again cooled to ca. 4 C~ Phosgene (1.5 ml. of a 4.3 M solution in chloroform 6.45 mmole~ is added and the cooling bath is removed. Stirring is continued for a further 1.5 hours, and then all ~he volatile components are removed by evaporation in vacuo. The~oily residue is redissolved in 6 ml. of chloroform and the solution is cooled to ca. 4 C.
~n an ice-bath. To the stirred solution ~s added 0.95 g. (6 mmole~ of tetra-methylguanidinium azide, and then stirring is continued for a further 1 hour at ambient temperature. At this point, 25 ml. of water is added, followed by suffi-cient lN sodium hydroxide to bring the pH of the aqueous phase to 10. The chloroform layer is removed, washed with water, dried using sodium sulfate, and evaporated to dryness in vacuo. This affords crude 6-(triphenylmethylamino)--2,2-dimethyl-3-(1-L4-trimethylsilyloxybenzy~ tetra2Ol-5-yl)penam~ which is purified by chromatography on silica gel using chloroform as eluant.
To a stirred solution of 200 mg. of the purified trimethylsilyloxy-benzyl derivative~ ~n 4 ml. of tetrahydrofuran, is added 0.3 ml. of 1.0N sodium hydroxide. The solution is stirred at ambient temperature for 50 minutes, and then the pH is ad~usted to 5.7 using 5% hydrochloric acid. The solvent is removed by evaporation in vacuo to yield c~ude 6-(triphenylmethylamino-2~2-dime~hyl.3-(5-tetrazolyl)penam.

10500~0 PREPARATION M
6-Amino-2~2-dimethy~-3-(5-tetrazolyl)penam To a slurry of dry acetone (5 ml.~ and 6-triphenylmethylamino-2,2-dimethyl-3-(5-tetrazolyl)penam (483 mg., 1.0 mmole) at r~om tPmperature is added p-toluenesulf~nic acid monohydrate (209 mg., 1.1 mmole). The resulting solution is stirred for 10 minutes and then ether (30 ml.) is added over a five minute period~ The mixture is stirred for ten minutes after which the solvent is decanted from the s~lid which separates. The solid is dissolved in tetra-hydrofuran ~30 ml.) and placed on a column ~300 x 6 mm.) packed with 10 ~. Df Florisil (synthetic magnesi~m silicate). The column is washed with tetrahydro~
furan until a total of 125 ml. is collected. The eluate is concentrated to dry-ness under reduced pressure at 40 C. to ~ive 210 mg, of solid. The solid is slurried in e~her (30 ml.), filtered, washed with ether and air-dried. Yield = 121 mg. (50/0). The NMR spectrum (in DMSO-d6) shows absorption bands at 1.08 ppm, (2s,-3H each, C-2 methyls), 4.60 + 5.52 (2d, J~4.0 H , 2U, H5 ~ H6), 5.10-(s, lH H3) and 5.88 (_, 3HJ NH3)PPm.- (5, 3H~, 1.54ppm (s, 3H), 4.60 ppm (d, 1~), 5.52 ppm (d~ 5.10 ppm`(s~ IH), and 5.88 ppm (s~ 3H).

10500~10 6-Amino-2,2-dimethyl-3-(2-~pivaloyloxymethyl~tetrazol-5-yl)- -penam To a stirred solution of 0.932 g. (7.21 m mole) of quinoline in 8.0 ml. of chloroform is added 0.840 g. (4.05 m mole) of phosphorus pentachloride.
The suspension is cooled to -15C., and then 1.81 g. (3.84 m mole) of 6-(2-phenylacetamido)-2~2-dimethyl-3-(2- fipivaloyloxymethylJtetrazol-S-yl)penam is added. Stirring is continued for a further 30 minutes, at ca. -5 C.~ and then 2.15 g. (35.7 m mole) of n-propanol is added. Stirring is continued for a 10 further 30 minutes, again at ca. -5 C.~ and then 25 ml. of 90:10 isopropyl ether-acetone is added, followed i~mediately by a solution of 1.35 g. of sodi-um chloride in 6.02 ~1. of water. The temperature rises to 15 C. and then it is lowered again to -15 C. The precipitate which has formed is filtered off and dried, giving 1.33 g. (88Z yield) of 6-amino-2,2-dimethyl-3-(2-Lpivaloyl-oxymethyl~tetrazol-5-yl)penam hydrochloride. The infrared spectrum (KBr disc) shows absorptions at 1785 c~ 1 (~ -lactam) and 1750 cm 1 (ester). The NMR spectrum (DMSO-d6) shows absorptions at 6.70 ppm (singlet~ 2H~ pivaloyloxy methylene hydrogens)~ 5.75 ppm ~doublet, lH, C-5 hydrogen)~ 5.50 ppm (singlet, 1~ C-3 hydrogen~ 5.70 ppm (doublet~ lH~ C-6 hydrogen), 1.75 ppm (singlet, 20 3H~ C-2 methyl hydrogens)~ 1.20 ppm (slngiet, 9N, t-butyl hydrogens) and 1.10 ppm (sin~let~ 3H~ C-2 methyl hydrogens).
.

-52_ ~050010 PREPARATION O
.. . .
6-Amino-2~2-dimethyl-3~ ivaloyloxymethyl~tetra_ l ~ yl)penam The title compound is prepared as its hydroçhloride, in 90%
yield, from 6-(2-phenylacetamido)-2,2-dimethyl-3-(1-Lpivaloyloxymethyl~-tetrazol-5-yl)penam, using the method of Preparation V. The infrared spectrum (KBr disc)-shows absorptions at 1780 cm ~ -lactam~ and 1740 cm (ester). The NMR spectrum (DMSO-d6) shows absorptions at 6.71 ppm (singlet~
2H, pivaloyloxy methylene hydrogens), 5.88 ppm (singlet, lH, C-3 hydrogen), 5.83 ppm (doublet, lH~ C-S hydrogen)~ 5.20 ppm (doublet~ lH, C-6 hydrogen)~ -1.80 pp~ (singlet, 3H, C-2 methyl hydrogens), 1.20 ppm (singlet, 9H, t-butyl hydrogens) and 1.16 ppm (singlet~ 3H~ C-2 methyl hydrogensi~.

~0500~Q
PREPARATION P
., - ~
6-Amino-2~2-dimethyl-3~ pivaloyloxymethyltetrazol-5-yl)penam' and 6-Amino-2,2-dimethyl-3-(2-pivaloyloxymeth~ltetrazol-5-yl)penam To a stirred suspension of 2.40 g. of 6-amino-2,2-dimethyl-3-(5-tetrazolyl~penam in 15 ml. of N~N-dimethylformamide, is added 2.ô ml. of triethylamine. Stirring is continued for a further 15 ~inutes, and then''2.68 g. of chloro~ethyl pivalate is added. The mixture is stirred at ambient temperature for 5 hours, -and then it is diluted with 100 ml. of water. It is jthen~extracted with ethyl acetate. The extràct is washet with water, dried using anhydrous sodium sulfate, and then it is evaporated in vacuo to give a ~ixture of the title compounds. The individual isomers are obtained by chro-matographic separation of the crude product.
Repetition of this procedure but substituting 3-bromophthalide or the appropriate alkanoyloxyalkyl chloride for pivaloylo~ymethyl chloride affords an isomeric mixture of the corresponding monoalkylated products in which the alkanoyloxyalkyl or phthalidyl substituent is located at the 1- or the 2-posi-tion of the tetrazole ring. The following co~pounds are thus prepared. (For convenience only the alkyl substituent is tabulated):
acetoxymethyl isobutyryloxymethyl hexanoyloxymethyl l-acetoxyethyl -l-pival'oyloxyethyl I-hexanoyloxyethyl ' ~ ' phth~lldyl .

.
.: :
-54_ . ~ .

~050010 PREPARATION O

6-(2-Phenylacetamido~-2,2-dimethyl-3-(5-~etrazolyl)penam A flask containing 965 ~g. of 6-amino-2,2-dimethyl-3-(1- ~ methoxy-benzylltetrazol-5-yl)penam p-toluenesulfonate~ 40 drops of anisole~ and 5 ml.
of trifluoroacetic acid is immersed in a water-bath maintained at 35-40C.
The progress of the reaction is followed by removing samples at intervals, and recording their nuclear magnetic resonance spectra. After about 25 minutes, the removal of the 4-methoxybenzyl group is found to be approxi~ately 90%
complete. At this point the reaction solution is added to a rapidly-stirred, ice-cold solution of 10 ml. of pyridine in 50 ml. of chloroform~ Stirring is continued for 5 minut~s~ and then 0.24 ml. of phenylacetyl chloride 15 added.
The cooling bath is removed and the reaction mixture is stirred for a further 20 minutes. A 100-ml. portion of water is added~ and the pH of the aqueous phase is then adjusted to 2.5 by the dropwise addition of 0.5 N hydrochloric acid. The chloroform layer is separated off, washed with saturated brine, dried usin~ anhydrous sodi~m sulfate and then it i5 evaporated to dryness in vacuo. Theecrude product thus obtained is re-dissolved lnschloroform~ and the solution is divided into two equal portions. To one of these portions is added an equal volume of water. The layers are stirred vigorously and the p~ of the aqueous phage is raised to 6.9 by the dropwise addition of 0.1~ sodium hydrox-ide so~ution. The chlorofonm is separatet off and discarded, and then an equal quantity of frèsh chloroform is added to the aqueous phase. The layers are stirred vigorously and the pH is ad~usted to 2,5 using dilute hydrochloric acid. The chloroform ~s separated off, washed with saturated brine, dried using anhydrous magnesium sulfate and then evaporated to dryness in vacuo.

~osoo~o This affords 197 mg. of an oily residue. The residue is re-dissolved in 3 ml.
of chloroform which is then added dropwise to 30 ml. of hexane. The fluffy white solid which precipitates is filtered off, giving 80 mg. of 6-(2-phenyl-acetamido)-2,2-dimethyl-3_(5_tetrazolyl)penam. IR)KBr disc): 1795, 1660 and -1.-1510 cm . NMR-(DCD13): 7.20 ppm (s~ 5H),5.55 ppm (m~2H)~ S.15 ppm (s~ lH)~

3.60 ppm (s, 2H), 1.40 ppm (s, 3H) and 1.05 ppm (s, 3H).

The MIC of the title compound against a strain of Streptococcus pyo-~enes is ~0.1 ~g/ml.

~osoo~
PP~EPARATION R
6-(2-Phenoxyacetamido)-2~2-dimethy1-3_(5-tetrazolyl)penam A stirred slurry of 480 mg. of 6-amino-2,2-dimethyl-3-(5-tetrazolyl)-penam in 10 ml. of water is cooled to 0C.~ and then the pH is a~justed to 8.0 usin~ lN sodium hydroxide. To this solution is then added 0~25 mol. of phenoxy-acetyl chloride, in portions, with the pH of the~solution being maintained between 7 and 8 during the addition, using 0.1N sodium hydroxide. The solu-tion is stirred for a further 30 minutes at O C. at pH 8. It is then extracted with chloroform, and the extracts are discarded. The aqueous phase is acid-ified ~n ~H 2 with dilute hydrochloric acid, and then it is ~urther extracted with chlorofo~m. The~latter extracts are dried using calcium sulfate and then evaporated in vacuo to ~ive the crude product as a gummy solid. This is puri-fied by dissolving it in 2~1ml.'Df chloroform, and adding the resultant solu~
tion dropwise to 250 ml. of hexane. The precipitate which forms is filtered off~ giving 385 mg. of 6 (2-phenoxyacetamido)-2,2-dimethyl-3-(5-tetrazolyl)-penam as a white amorphous sol$d. IR spectrum (KBr disc): 1785, 1670 and 1540 cm . NNR spectrum (DMSO-d6): 7.50-6.70 ppm (m~5H~ 5.7~ ppm (m,2H~, 5.35 ppm (s, 3H), 4.60 ppm (s, 2H), 1.60 ppm (s, 3H) and 1.05 ppm (s, 3H).
The MIC of the title compound against a strain of Streptococcus ~yogènes is ~0.1 ~glml.
v~

' ' '~'.

'' , ,"
-57- ~

~. .... .

~0500~0 PREPARATION S
6-(D-2-Amino-2-phenylacetamido)-2~2-dimethy1-3-~5-tetrazolyl) Penam . , , To a stirred solution of 23.8 ml. of ethyl chlorofor~a~e in 6~0 ml.
of acetone, is added 25 ml. of a 3% solution of N-methylmorpholine in acetone.
The resulting solution is cooled to -40C., and then 75.2 g. of sodium N-(2-methoxycarbonyl-l-methylvinyl)D_~_a~no-2-phenylacetate is added. The temperature is ad~usted to -20C. and stirrin~ is continued for 28 minutes.
The solution is re-cooled to -40C.~ and an ice-cold solutio~ prepared by suspending 60.0 g. of 6-amino-2,2-dimethyl-3-(5-tetrazolyl)penam in 250 ml. of water and then adjusting the pH to 7.0, is added. The resulting solution is stirred for 30 minutes withou~ further cooling, and then the acetone is removed by evaporation in vacuo. To the aqueous residue is added an equal volume of tetrahydrofuran, and then, at 5C. the pH is ad~usted to 1.5 with dilute hydrochloric acid. The mixture is held at this temperature and pH for 30 minutes, and then the tetrahydrofuran is removed by evaporation in vacuo. The aqueous residue is extracted with ethyl acetate, followed by ether, and the extracts are discardet. The pH of the remaining aqueous phase is raised to 5.4~ and the product begins to crystallize out. After 1 hour it is filtered off and dried. The crude yield is 68.8 g.
The product ~is susppnded in water at 25C., and the pH is lowered to 1.5. After stirring for ~ short period, the insoluble materials are filtered off, and the filtrate is extracted with ether. The aqueous solution is then cooled to 5C., and the pH is ad~usted to 5.2. The solid which precipitates ~s filtered off, giving 62.7 8. (58.7% yield) of 6-(D-2-amino-2-phenylacetamido)~2~2-d$methyl-3-(S-tetrazolyl)penam trihydrate~ m.p. 201_202c.,Lq3D5 ~ 228.2 ~1% in CH30H). IR (KBr disc): 1780 cm (~-lactam), ~MR (in DMSO-d6/D20): ;

.

., _58-~050010

7.60 ppm ts~ 5H), 5.70 ppm (d, lH~, 5.55 ppm (d, lH), 5.20 ppm (s, lH), 5115 ppm (d, lH), 1.50 ppm (s, 3H), 0.90 ppm (s, 3H).

Analvsis - Calcd. for C16Hl9O2N7S~ 3H20 (percent): C~ 44.95;
H, 5.89; N, 22.94; S, 7.50. Found (percent): C~ 45.01; H, 5.84; N, 22.81;
S, 7.34.
The sodium N-(2-methoxycarbonyl-1-methylv-nyl)~D-2-amino-2-phenyl-acetate is prepared from methyl acetoacetate and D-2-amino-2-phenylaceti~
acid by the procedure used by Long et al. (J. Chem. Soc., London, Part C, 1920 [1971~) for the corresponding p-hydroxy compound.
The MIC of the title compound against a strain of Streptococcus pyogenes is~O.l ~g/ml.

59_ ~osoo~o PREPARATION T
.. .. . . . _ ..
6-(D-2-Amino-2-~4-hydroxyphenyl3acetamido)-2~2 dimethyl-3-(5-tetrazolvl)~enam To a stirred solution of 0.19 ml. of ethyl chloroformate in 15 ml.
of dry acetone, cooled to 0C., is added 1 drop of N-methylmorpholine~ ~
followed by 576 mg. of sodium N-(2-methoxycarbonyl-1-methylvinyl)-D-2-amino-2-(4-hydroxyphenyl)acetate (Long et al ~ Journal of the Chemical Society ~-~London~ ~ Part C, 1920 1971 . The mixture is stirred for a further 30 mlnutes, and then it is c~oled to about -35C. To it is then added an ice- ;
cold solution~-of the sodium salt of 6-amino-2~2-dimethyl-3-(5-tetrazolyl3-penam, prepared by adding 10% sodium hydroxide to a suspension of 436 mg. of 6-amino-2,2-dimethyl-3-(5-tetrazolyl)penam in 5 ml. of water (to give a pH of 7.8)~ followed by dilution with 25 ml. of acetone. The cooling bath is re-moved, and the reaction mixture is stirred for a further 30 minutes. At this point, the acetone is removed by evaporation under reduced pressure, and then 20 ml. of methyl isobutyl ketone is added to the aqueous residue. The two-phase system is cooled to 10C., acidified to pH-= 0.9 with dilute hydro-chioric acid, and then it is stirret at 10C. for 1 hour. The methyl iso-buty ketone is removed and discarded. The p~ o~ the aqeuous phase is raised to 6.6~ and then it is stored in the refrigerator for 3 hours. The precipitate which forms is filtered off, giving 320 mg. of 6-(D-2-amino-2-L4-hydroxyphenyl~acetamido-2,2~dimethyl-3-(5-tetrazolyl)penam. The infrared sp~ctrum (KBr disc) of the product shows absorptions at 1775 cm 1 ~-lactam carbonyl) and 1680 cm l (amide I bsnd). The NMR spectrum ~n DMSO-d6/D2O/
shows absorptions at 7.35 ppm and 6.85 ppm (2 doublets, aromatic hydrogens), 5.60 ppm (quartet, C~S and C-6 hydrogens~, 5.10 ppm (multiplet, benzyl hydro-; -~en and C-3 hydrbgen)~ 1.45 ppm ~singlet~ C-2 methyl hydrogens3 ant 0.95 ppm (singlet~ C-2 methyl hydrogens).

~- The MIC of the title compound against a strain of Streptococcus ~yo~ es is 0.1 ~gjml~

1~50010 PREPARATION U
.
6-(2-Phenylacetamido)-2~2-dimethyl-3~ pivaloyloxymethyl -tetrazol-5-yl)penam and 6-(2-Phenylacetamido)-2,2-dimethyl-3-(2- pivaloyloxymethyl tetrazol-5-yl)penam To a stirred suspension of 10.0 g. (0.0264 mole) of 6-(2-phenyl-acetamido)-2,2-dimethyl-3-~5-tetrazolyl)penam sodium salt, in 105 ml. of acetone, is added 2.6 ml. of 25% aqueous sodium iodide, followed by 4.35 g.
(0.0290 mole) of chloromethyl pivalate. The mixture is refluxed for 4.5 hours, and then it is cooled to ambient temperature. To the mixture is then added 100 ml. of water, and the resulting suspension is extracted with ethyl acetate.
The extracts are dried and evaporated to give 6.3 g. of white foam. The MIC of this mixture of the title compounds against ~ Vogenes in 0.2 ug/ml.
The white foam is re-d~ssolvet in small volume of 80:20 chloroform-ethyl acetate and absorbed on a column of lôO g. of chromatographic grade s~lica ~el. The column is then eluted with 80:20 chlorofonm-ethyl acetate tak~ng fractions. ~ach fraction consists of 700 drops of solvent. Fractions 55-95 are combined and evaporated in vacuo to give 2.03 g. of 6-(2-phenylacet-amido~-2~2-dimethyl-3-(2- piv~loyloxymethyl tetrazol-5-yl)penam. IR (KBr disc~:
1785, 1760, 1670 and 1515 cm . NMR (DMSO-d6/D20): 7.50 (s, 5H), 6.70 (s, 2H)~ -fi.OO-5.60 (m, 2H), 3.85 (s, 2H), 1.65 (s, 3H)~ 1.36 (s~ 9H) and 1.20 ~s~ 3H) ppm. Frac~ions 100-164 are combined and evaporated in vacuo to give 0.80 g, of ~- -6-~2-phenylacetamido)-2,2-dimethyl-3-(1- pivaloyloxymethyl tetra~ol-5-yl)penam IR(KBr disc~: 1780~ 1760, 1670 and 1515 cm . NMR (DMSO-d6(D20): 7.50 (s, 5H) 6.80 (s, 2H), 6.50 (s, 2H), 5.60 (s~ lH)~ (s, 2H), 1.75 (s, 3H), 1.36 (s, 9H) and 1.34 (s, 3H) ppm.

.

.. .. . . , . ~ , ~0500~0 :-PREPARATION V

6-(2-Phenylacetamido)-2~2-dimethyl-3~ 2 ~ ~1-acetoxyethyl3-tetra_ol-5-yl)penam Reaction of 6-(2-phenylacetamido)-2,2-dimethyl-3-(5-tetrazolyl~penam sodium salt with l-acetoxyethyl chloride, according to the procedure of Preparation U
produces the title compound as a mixture of isomers, m.p. 55-70 C., yield 28%. IR (KBr disc): 1780, 1770, 1670 and 1515 cm . NMR (CDC13): 7.20 (s, 6H), 6.25 (m, lH), 5.75-5.40 (m, 2H), 5.20 (s, lH), 3.60 (s, 2H), 2.00 (m, 6H), 1.45 (s, 3H) and 0.95 (s, 3H) ppm.

10~0010 PREPARATION W

6-(2-Phenylacetamido)-2,2-dimethyl-3-(1-l2l-~3-phthalidyl tetrazol-5-yl)penam _ Reaction of 6-(2-phenylacetamido)-2,2-dimethyl-3-(5-tetrazolyl)penam sodium salt with 3-bromophthalide, according to the precedure of Preparation U
produces the title compound as a mixture of isomers~ m.p. 70-85C~, yield 91%. IR (KBr disc): 1785~ 1675 and 1500 cm . NMR (CDC13~: 8.05 - 7.10 (m~ 9H)~ 6.55-6.20 (m, 2H), 5.ô0 (m~ 2H)~ 5.20 (m~ lH)~ 3.60 (s~ 2H), 1.60 (s~ 3H) a~d 1.00 (s~ 3H) ppm.

_63-~05Q010 PREPARATION X
.
6-(2-Phenylace~amido)-2,2-dimethyl-3-(l ~4-benzyloxybenzyl~tetrazol-5-yl)penam To a stirred solution of 189 mg of j6-amino-2,2-dimethyl-3-tl-~4-benzyloxybenzyl~tetrazol-5-yl)penam in 4 ml of chloroform, is added, at ambient temperature, 0.038 ml of pyridine followed by 0.057 ml of phenyl~
acetyl Ghloride. Stirring is continued for a further 45 minutes, and then the reaction mixture is diluted with 25 ml of chloroform and then washed with water. The organic phase is dried using anhydrous magnesium sulfate and then evaporated in vacuo. The residue is 209 mg (86% ~yield) of 6-~2-phenylaceta-mido)-2,2-dimethyl-3-(1-~4-benzyloxybenzyl~tetrazol-5-yl)penam. The NMR
spectrum (in CDC13) shows absorptions at 7.50-6.70 ppm ~multiplet~ aromatic hydrogens), 6.4 ppm (doublet, amide hydrogen), 5.80-5.20 ppm (multiplet, benzyl hydrogens and C-5 and C-6 hydrogens), 5.10 ppm (singlet, C-3 hydrogen), 5.05 ppm (singlet, benzyl hydrogens), 3.60 ppm (singlet, phenylacetyl methyl-ene hydrogens), 1.30 ppm (singlet, C-2 methyl hydrogens) and 0.85 ppm (singlet, C-2 methyl hydrogens).

ll . 1050010 . ~ I ~
: PREP~RATIO~ Y , 6-(2-Phenylaceta~ido)-2,2-dimethyl-3-(1-[2]-[methoxymethyl]
. . _ tetra~ol-5-yl)penam . . . Reaction of 6-(2-phenylacetamido)-2,2-dimethyl-3-(5-t~trazOlyl)penam . sodium salt with chloromethylmethyl ether according to the procedure of Prepar~
¦r{OII U pro ces -h~ - co~po~d s a mi~u~e -E isn~

' 1 ' ' ' - ~, , '. ' . ',' ' ' ''' .'~ ' ,, ' ' ' ,.
.,' .' . , '. '- .
~ ~ ~ ' ''' ' ~ . ' ,.', .' ' ' '', ' ,,' .. .

. ''. ''' . 1 !T,ro~ ~ . .~ 3~'',~ ; .

Claims (2)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for preparing a 3-methyl-4-(5-tetrazolyl-.DELTA.3-cephem of the formula:

wherein Y is selected from the group consisting of and wherein R2 is selected from the group consisting of hydrogen, alkanoyloxymethyl having from three to eight carbon atoms, 1-alkanoyloxyethyl having from four to seven carbon atoms, methoxy-methyl and phthalidyl;
R1 is selected from the group consisting of R2 and wherein R6 is selected from the group consisting of hydrogen, alkyl having from one to three carbon atoms and phenyl; R7 is selected from the group consisting of hydroxy, methoxy, alkanoyl-oxy having from two to four carbon atoms and benzyloxy; and R8 is selected from the group consisting of hydrogen, hydroxy, fluoro, chloro, bromo, iodo, methyl, methoxy, alkanoyloxy having from two to four carbon atoms, phenyl and benzyloxy or wherein each of R9 and R10 is selected from the group consist-ing of hydrogen and methyl; and X is selected from the group con-sisting of oxygen and sulfur;
R? is selected from the group consisting of (a) hydrogen, 2,2,2-trichloroethoxycarbonyl, 2,2,2-tribromoethoxycarbonyl, benz-yloxybenzyl; (b) 2-phenylacetyl, 2-phenoxyacetyl, 2-amino-2-phen-ylacetyl; and (c) wherein R3, R4 and R5 are each selected from the group consisting of hydrogen, chloro, bromo, fluoro, alkyl having from one to four carbon atoms, alkoxy having from one to four carbon atoms and phenyl, which comprises heating a 6-amino or 6-substituted-amino-2,2-dimethyl-3-(5-tetrazolyl)-penam sulfoxide of the formula:

in the presence of an acid reacting substance at a temperature of from 80°C.-175°C. for a time sufficient to effect conversion thereof.

2. A method according to claim 1, wherein R is 2-phenyl-acetyl or 2-phenoxyacetyl and R1 is p-methoxybenzyl.