CA1269106A - 4-substituted diazolidinones - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

The present invention as disclosed provides 4-substituted 1-(optionally substituted)-diazolidinones which are compounds of Formula I:

I

wherein:
R1 and R2 are a) taken together to form a phthalimido group; or b) either R1 or R2 is hydrogen and the other of R1 or R2 is an amino-protecting group; and R3 is hydrogen or trihaloacetyl; or an acid-addition salt thereof.
These compounds are intermediates to 7-substituted bicyclic pyrazolidinone antimicrobials.

Description

9~

This invention is directed to 4-substituted diazolidinone compounds which are intermediates for 7-substituted bicyclic pyrazolidinone antimicrobials.
The present invention embraces compounds of the Formu~a I:

R1 , _~-R3 1 0 ~N~V~
R2 ~9 2 IH

wherein R1, R2 and R3 are as defined below.
The ring system of the compound of Formula I
is a 4-(substituted amino)-3-oxo-1,2-diazolidine, which for brevity's sake will be referred to as a "diazoli-dinone" compound. In the above Formula I, the undulat-ing line between position 4 of the diazolidinone ring and the protected amino group indicates that the instant diazolidinone compounds exist either as a mixture of varying proportions of enantiomers or as the pure 4~(R) or the pure 4-(S) enantiomer.
In the above Formula I, R1 and R2 are a) taken together to form a phthalimido group; or b) either R1 or R2 is hydrogen and -the other of R1 or R2 is an amino-protecting group;
or an acid-addition salt thereof.
R3 in the above Formula I is either hydrogen or trifluoroacetyl.

i~i9~U~i The terms "amino-protecting group" and "pro-tected amino" as used in the specification refer to substituents of the amino group commonly employed to block or protect the amino functionality while carrying out reactions at other functional groups on the compound.
Examples of such amino protecting groups include the formyl group, the trityl group, the phthalimido group, the trichloroacetyl group, the chloroacetyl, bromoacetyl and iodoacetyl groups, urethane-type blocking groups such as benzyloxycarbonyl, 4-phenylbenzyloxycarbonyl,

2-methylbenz.yloxycarbonyl, 4-methoxybenzyloxycarbonyl, 4-fluorobenzyloxycarbonyl, 4-chlorobenzyloxycarbonyl,

3-chlorobenzyloxycarbonyl, 2-chlorobenzyloxycarbonyl, 2,4-dichlorobenzyloxycarbonyl, 4-bromobenzyloxyca.rbonyl, 3-bromobenzyloxycarbonyl, 4-nitrobenzyloxycarbonyl,

4-cyanobenzyloxycarbonyl, 2-(4-xenyl)iso-propoxycar-bonyl, 1,1-diphenyleth-1-yloxycarbonyl, 1,1-diphenyl-prop-1-yloxycarbonyl, 2-phenylprop-2-yloxycarbonyl, 2-(p-toluyl)prop-2-yloxycarbonyl, cyclopentanyloxy-carbonyl, l-methylcyclopentanyloxycarbonyl, cyclo-hexanyloxycarbonyl, l-methylcychexanyloxycarbonyl, 2-methylcyclohexanyloxycarbonyl, 2-(4-toluylsulfonyl)-ethoxycarbonyl, 2-(methylsulfonyl)ethoxycarbonyl, 2-(triphenylphosphino)ethoxycarbonyl, 9-fluorenyl-methoxycarbonyl ("FMOC"), 2-(trimethylsilyl)ethoxy-carbonyl, allyloxycarbonyl, l-(trimethylsilylmethyl)-prop-l-enyloxycarbonyl, 5-benzisoxalylmethoxycarbonyl, 4-acetoxybenzyloxycarbonyl, 2,2,2-trichloroethoxycar-bonyl, 2-ethynyl-2-propoxycarbonyl, cyclopropylmethoxy-carbonyl, 4-(decyloxy)benzyloxycarbonyl, isobornyloxy-carbonyl, 1-piperidyloxycarbonyl and the like, the ~i9.~0 benzoylmethylsulfonyl group, the 2-(nitro)phenylsul-fenyl group, the diphenylphosphine oxide group and like amino protecting groups. The species of amino-protect-ing group employed is not critical so long as the deriva-tized amino group is stable to the condition of subse-quent reaction(s) on other positions of the diaæolidinone molecule and can be removed at the appropriate point in the synthesis of 7~substituted bicyclic pyraæolidinone antimicrobials without disrupting the remainder of the molecule.
In particular, it is important not to subject the amino-substituted diazolidinone molecule (wherein R3 is hydrogen) to strong nucleophilic bases or reductive conditions employing highly activated metal catalysts such as Raney nickel.
Preferred amino-protecting groups are the allyloxycarbonyl, the t-butoxycarbonyl and the trityl groups. Similar amino-protecting groups used in the cephalosporin, penicillin and peptide art are also em-braced by the above terms. Further examples of groupsreferred to by the above terms are described by J.W.
Barton, "Protective Groups In Organic Chemistry", J.G.W.
McOmie, Ed., Plenum Press, New York, N.Y., 1973, Chapter 2, and T.W. Greene, "Protective Groups in Organic Synthesis", John Wiley and Sons, New Yor~, N.Y., 19~1, Chapter 7.
The term "acid addition salt" encompasses those salts formed by standard acid-base reactions with amino groups and organic or inorganic acids. Such acids include hydrochloric, sulfuric, phosphoric, acetic, suc-cinic, citric, lactic, maleic, fumaric, palmitic, i9~

X-671].A -4-cholic, pamoic, mucic, D-glutamic, d-camphoric, glutaric, phthalic, tartaric, lauric, stearic, salicyclic, d-10-camphorsulfonic, methanesulfonic, benzenesulfonic, para-toluenesulfonic, sorbic, picric, benzoic, cinnamic and like acids.
The compounds of Formula I also embrace the correspondlng crystalline solvates. Thus, diazoli-dinones that crystallize with any number of (or any fraction thereof) of molecules of the mother liquor solvent are a part of the instant invention. The mother li~uor solvent can be water or an organic solvent.
Examples of the compounds of Formula I include:
4-(R,S)-(t-butoxycarbonylamino)-3-oxo-1,2-diazolidine, 4-(S)-(t-butoxycarbonylamino)-3-oxo-1,2-diazolidine, 4-(R)-(t-butoxycarbonylamino)-3-oxo-1,2-diazolidine, 4-(R,S)-(i-butoxycarbonylamino)-3-oxo-1,2-diazolidine p-toluenesulfonate salt, 4-(S)-(allyloxycarbonylamino)-3-oxo-1,2-diazolidine, 4-(S)-(trityiamino)-3-oxo-1,2-diazolidine, 4-(S)-(benzyloxycarbonylamino)-3-oxo-1,2-diazolidine, 4-(R,S)-(allyloxycarbonylamino)~3-oxo-1,2-diaæolidine d-10-camphorsulfonate salt, 4-~R,S)-(tritylamino)-3-oxo-1,2-diazolidine, 4-(R,S)-(trichloroacetylamino)-3-oxo-1,2-diazolidine, 4-(R,S)-(benzolycarbonylamino)-3-oxo-1,2-diazolidine, 910~3 4-(R,S)-(chloroacetylamino)-3-oxo-1,2-diazolidine, 4-(R,S)-(4-methoxybenzyloxycarbonylamino)-3-oxo-1,2-diazolidine, 4-(R,S)-(cyclohexanoyloxycarbonylamino)-3-oxo-1,2-diazolidine, 4-(R,S)-(4-nitrobenzyloxycarbonylamino)-3-oxo-1,2-diazolidine, 4-(R,S)-(l,1-diphenylethoxycarbonylamino)-3-oxo-1,2-diazolidine, 4-(R,S)-(2-(methylsulfonyl)ethyloxycarbonyl-amino)-3-oxo-1,2-diazolidine, 4-(R,S)-(2-(trimethylsilyl)ethyloxycarbonyl-amino)-3~oxo-1,2-diazolidine, 4-(R,S)-(2,2,2-trichloroethoxycarbonylamino)-3-oxo-1,2-diazolidine, 4-(R,S)-(benzoylmethylsulfonylamino)-3-oxo-1,2-diazolidine, 4-(R,S)-(t-butoxycarbonylamino) l-(trifluoro-acetyl)-3-oxo-1,2-diazolidine, 4-(R,S)-(allyloxycarbonylamino)-1-(trifluoro-acetyl)-3-oxo-1,2-diazolidine), 4-(R,S)-(trimethylsilylamino)-1-(trifluoro-acetyl)-3-oxo-1,2-diazolidine), 4-(R,S)-(tritylamino)-1-trifluoroacetyl)-3-oxo-1,2-diazolidine, 4-(R,S)-benzyloxycarbonylamino~-3-oxo-1,2-diazolidine, 4-(R,S)-(trichloroacetylamino)-3-oxo-1,2-diazolidine, 0~

4-(S)-(t-butoxycarbonylamino)-l-(trifluoro-acetyl)~3-oxo-1,2-diazolidine, 4-(S)-(allyloxycarbonylamino)-1-(trifluoro-acetyl)-3-oxo-1,2-diazolidine, 4 (S)-(trimethylsilylamino)-1-~trifluoroacetyl)-3-oxo-1,2-diazolidine, or 4-(S)-(tritylamino)-1-(trifluoroacetyl)-3-oxo-1,2-diazolidine;
and the p-toluenesulfonic acid addition salt of the above non-salt examples.
A preferred group of compounds of Formula I
is the p-toluenesulfonic acid addition salt. A second preferred group of compounds of Formula I is when R1 or R2 is hydrogen and the other is t-butoxycarbonyl, and the corresponding p-toluenesulfonic acid addition salt.
A third preferred group of compounds occurs when the C4 carbon of the diazolidinone ring is in the S configuration. Preferred compounds with the third preferred group have either R1 or R2 as hydrogen and the other as t-butoxycarbonyl.

The synthesis of enantiomeric mixtures of diazolidinones of Formula I is outlined below in Scheme I.

Scheme 1 CHaO f OH
NH-(t-Boc) protected serine 1) 1 TsCI

0~, 15 CH30/ ~/ O--Ts tosyl serine NH-(t-~oc) 2 ) ~ NH2NH2 H ~ NH
(t-Boc)-N~,~a race~ic ~ -NH diazolidine The above Scheme depicts the synthesis of 4-(t-butoxycarbonylamino) diazolidinone compounds.
Diazolidinone compounds with different amino protecting groups are obtained from serine derivatized with an amino-protecting group other than t-butoxycarbonyl.

~i9:1~3~i The tosylate group (OTs) can be replaced by any other appropriate leaving group such as mesylate.
Similarly, those skilled in the art will appreciate that amino protecting groups other than -t-butoxycarbonyl (t-Boc) can be utilized. The first step in the syn-thesis o~ l-(unsubstituted)diazolidinones, represented by Reaction 1 in the above Scheme, is the tosylization of the hydroxy group of the protected serine derivative.
The tosylization is carried out in methylene chloride with p-toluenesulfonyl chloride in the presence of a catalytic amount of 4-dimethylaminopyridine and greater than one equivalent of pyridine. The reaction mixture is stirred at room temperature overnight.
The tosylated serine obtained is reacted with 97% hydrazine to give enantiomeric mixtures of 1-(unsubstituted)diazolidinones, as depicted in Reaction 2.
Reaction 2 should be carried in polar solvents such as chlorinated hydrocarbons, cyclic or acyclic ethers or C1 to C~ alcohols. A preferred group of solvents for the reaction is dichloromethane, methanol and chloro-form, with dichloromethane being more preferred.
The temperature for Reaction 2 is not criti-cal. It is preferred that the reaction be carried out between about room temperature to about the freezing temperature of the solvent. A more preferred tempera-ture is approximately room temperature.
The reaction usually requires a period of about one to about forty-eight hours. The optimal reac-tion time can be determined by monitoring the progress of the reaction by conventional means such as chromato-graphic techni~ues (thin layer chromatography, high per-91~3~.3 formance liquid chromatography, or column chromatography) and spectroscopic methods, alone or in conjuction with chromatographic techniques, such as infrared spectros-copy, nuclear magnetic resonance spectrometry and mass spectrometry. A preferred time period is from between about five to about sixteen hours.
The usual stoichiometry for Reaction 2 in the above Scheme 1 is a 4:1 ratio of hydrazine to tosyl serine reagent. Of course, a 1:1 ratio of reagents is permissible. It is preferred that the hydrazine reagent be present in excess, and especially preferred that the hydrazine be present in a 4:1 excess. Furthermore, the order of addition of either reagent is not critical.
The stereospecific synthesis of chiral dia-lS zolidinones of Formula I is diagrammed below in Scheme 2.

9~

X-6711A -10~

Scheme 2 ~ Protected serine H0/ \~/ NH-NH~ acyl hydrazide NH-(t-Boc) l 3) ET-TFA

~ ~ g N-(Trifluoroacetyl) H ~ 1 NH-NH CF3 acyl hydrazide NH-(t-Boc) l ~) DEAD, TPP

H ,~ ~ CFo Chiral t-60cN~c~ -(Trifluoroacetyl) ~-NH diazolidine l 5) hydroxide ion t-BocN~ Chiral ~-NH

10~

X-6711A -ll-The above Scheme depicts the sy~thesis of 4~(S)-(t-butoxycarbonylamino)diazolidine compounds.
Diazolidine compounds with the 4-(R) configuration are synthesized by starting with the protected D-serine acyl hydrazide instead of the L-isomer depicted above.
Chiral diazolidines with amino-protecting groups other than t-butoxycarbonyl are synthesized starting with a serine acyl hydrazide derivatized with an amino-protecting group other than t-butoxycarbonyl.
The protected serine acyl hydrazide precursor of Scheme 2 is synthesized in a procedure analogous to B. Iselin and R. Schwyzer, Helv. Chim. Acta, 44, -p 169 (1961). The precursor is acylated with the tri-fluoroacetyl moiety, as set forth in Reaction 3 in the Scheme. The acylation is carried out in ethanol with an excess of ethylthio trifluorothioacetate ("ET-TFA").
The reaction mixture is stirred at room temperature for 65 hours.
The l-(trifluoroacetyl)acyl hydrazide obtained from Reaction 3 is reacted with triphenylphosphine ("TPP") and diethyl azodicarboxylate ("DEAD"), as depicted above in Reaction 4. (Although the above Scheme depicts only the use of DEAD, the reaction will also proceed if either dimethyl azodicarboxylate or di(iso-propyl)azodicarboxylate are substituted in the reaction.) In addition, the racemic serine acyl hydrazide can be utilized as a starting material, and other trihaloacetyl derivatives similarly provided can be ring closed to yield racemic trihaloacetyl diazolidines.
As one skilled in the art will appreciate, any trihaloacetyl group which serves as an effective electron-withdrawing group (on the acyl hydrazide) would 3~

~-6711A -12-be efficacious. Such other trihaloacetyl derivatives can be prepared by using ethylthio trihalothioacetates as the acylating agent in Scheme 2.
The stoichiometry of the process of Reaction 4 has the N-(trifluoroacetyl)acyl hydrazide, phosphine and diethyl azodicarboxylate reagent present in at least approximately a 1:1:1 molar ratio. The reaction will proceed in the presence of molar excesses above this ratio of any of the reagents or of the starting material.
The reaction is initiated by first combining (in any order) the solvent, the l-(trifluoroacetyl)acyl hydrazide and the phosphine, and secondly adding the azodicarboxylate reagent.
The reaction temperature of Reaction 4 is a not critical parameter. The process can be carried out from approximately the freezing point to approx-imately the reflux temperature of the solvent. The preferred temperature is approximately room temperature.
The duration of Reaction 4 can be from approximately five minutes to approximately twenty four hours. The progress of the process can be monitored by standard methods (for example, thin layer chromatography, high performance liquid chromatography, etc.) The process is stopped when the monitoring method demon-strates that the reaction is substantially complete.
The solvents for Reaction 4 are aromatic hydro-carbon solvents such as benzene, toluene, xylenes, etc.; ethers such as diethyl ether, tetrahydrofuran, or 1,4-dioxane; chlorinated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, dichloroethane, or chlorobenzene; amides such as dimethyl-formamide and dimethylacetamidei and other solvents such as hexamethylphosphoramide. Tetrahydrofuran is the 9'1(3~

preferred solvent. It is also desirable, but not essential, to dry and deoxygenate the solvent before use in the process.
The chiral l-(trifluoroacetyl)diazolidine S obtained from Reaction 4 is deacylated with dilute sodium hydroxide solution to yield the chiral l-(unsubstituted)diazolidine. The deacylation reaction is represented as Reaction 5 in Scheme 2. The Reaction entails generally suspending the chiral l-(trifluoro-acetyl)diazolidine in water then adding at least twoequivalents of dilute aqueous sodium hydroxide solution.
(For instance, a two-fold excess of lM sodium hydroxide can be used. Preferably, sufficient sodium hydroxide solution is added to give the reaction solution an initial pH of from between about 11 to about 12). The resultant solution stirred from about 10 minutes to about 3 hours at a temperature from about 10C to 25C.
When the reaction is substantially complete the reaction solution is neutralized by the addition of dilute acid, such as lN hydrochloric acid.
The optimal reaction time for Reaction 5 can be determined by monitoring the progress of the reaction by conventional means such as chromatographic techniques (thin layer chromatography, high performance liquid chromatography, or column chromatography) and/or spectro-scopic methods, such as infrared spectroscopy, nuclear magnetic resonance spectrometry and mass spectrometry.
A preferred reaction time period is from between about 30 minutes to about 1.5 hours. The above chiral synthesis can be modified to yield racemic product, if desired.

~2~

The diazolidinones of Formula I are intermedi-ates to pyrazolidinium ylides of the Formula II:
~ frR4 R1> /5 ' ~Rs R~ ~3 2~ II

In the above Formula II, R1 and R2 are 1) taken together and form a phthalimido group; or 2) either R1 or R2 is hydrogen and the other of R1 or R2 is an amino protecting groupi and R4 and R5 are the same or different and are hydrogen, C1 to C6 alkyl, C1 to C6 substituted alkyl, C~ to C12 arylalkyl, C7 to C12 substituted arylalkyl, phenyl, substituted phenyl or a group of the formula wherein R6 is C1 to C6 alkyl, C1 to C6 substitu-ted alkyl, C~ to C1 2 arylalkyl, C~ to C1 2 substituted 2~ arylalkyl, phenyl, substituted phenyl, a carboxy protecting group, or a non-toxic, metabolically-labile ester-forming group.
The ylides of Formula II are synthesized by condensing a ketone or aldehyde with a 1-(unsubsti-tuted)diazolidine of Formula I.

1~i9~

As a useful alternative procedure, the ketal of the ketone may be condensed with the diazolidine in the presence of an acid. For example, the diazolidine reagent is combined with acetone dimethyl acetal in methanol and then the solution is treated with d-10 camphorsulfonic acid. The mixture is refluxed for 1.5 hours to give the dimethyl ylide (i.e., R4 and R5 are methyl). The unsubstituted ylide (when R4 and R5 are hydrogen) is synthesized by combining the diazolidine reagent and 37% aqueous formaldehyde in methanol and stirring the mixture for between about twenty minutes to about 1.5 hours at room temperature. When R4 and R5 are different those skilled in the art will recognize that this final reaction will produce a mixture of E and Z
isomers.
Chiral pyrazolidinium ylide intermediates (wherein C~ is either in the (R) or (S) configuration) are syntheslzed from the corresponding chiral l-(unsub-stituted)diazolidines of Formula I using the above-described conditions.
The synthesis of the above pyrazolidiniumylide intermediates are further described by L.N.
Jungheim and R.E. Holmes, Canadian Patent Application No .
507,782, filed Aprll 28, 1986.

~i9~

The ylides of Formula II are intermediates to 7-substituted bicyclic pyrazolidinone antimicrobials of Formula III

R2~

In Formula III, R4 and R5 include the substituents for R4 and Rs of the ylides of Formula II plus a carboxylic acid or a carboxylate salt. R1 and R2 of Formula III
include all the substituents of the corresponding terms in Formula II plus substituents when either R1 or R2 is hydrogen and the other is an acyl group derived from a C1 to C30 carboxylic acid. (Examples of such acyl groups are the acyl groups bonded to the 6- and 7-amino groups of penicillins and cephalosporins, respectively).
R7 and R8 in Formula III can be a variety of substitu-ents, including a group of the formula -COORg wherein R~ includes the substituents of the above R6 plus, for example, hydrogen or an organic or inorganic cation. Further examples of substituents at R1, R2, R3, R4, R5, R7 and R8 in Formula III can be found in L.N.
Jungheim, S.K. Sigmund, C.J. Barnett, R.E. Holmes and R.J. Ternansky, Canadian Patent Application No. 507,777, 30 filed April 28, 1986.

91~

The 7-substituted bicyclic pyrazolidinones of Formula III are synthesized, for example, by various 1,3-dipolar cycloaddition reactions with the ylides of Formula II. One method of cycloaddition reaction, (the addition of an ylide and a substituted acetylene) is represented below in Scheme 3:

Scheme 3 Rs Rz\ ~ R~ I R~

ylide (II)acetylene III

In the above Scheme 3, for brevity's sake, Formula III indicates only one of the two possible 2,3-regioisomer products of the reaction. The reaction represented by Scheme 3 can also produce the opposite 2,3-regioisomer as well as a mixture of the regioisomers.
In the above Scheme R1, R2, R4 and Rs are as defined above for Formula II, R7 and R8 are as defined for Formula III and either R1o or R11 is an amino pro-tecting group and the other of R1o or R11 is hydrogen.
When carrying out the reaction it is preferable to s'' derivatize with protecting groups any of the acidic groups represented by R4, R5, R7 or R8. Examples of such acidic groups are the carboxylic acid group and the hydroxyimino group. It is especially preferred that any carboxylic acid groups be protected.
The reaction should be carried out in ~protic solvents. Examples of such solvents are the chlorinated hydrocarbons, the aromatic hydrocarbons and alkyl or aromatic cyano solvents. The preferred solvents for the above reaction are dichloromethane, acetonitrile, and 1,2-dichloroethane.
The temperature for the reaction is not criti-cal. It is preferred that the reaction be carried out between about room temperature to about the reflux tem-perature of the solvent.
The reaction usually requires a period ofabout 1 to about 168 hours. The optimal reaction time can be determined by monitoring the progress of the reaction by conventional means such as chromatographic techniques (thin layer chromatography, high performance liquid chromatography, or column chromatography) and spectroscopic methods (alone or in conjuction with chromatographic techniques), such as infrared spec-troscopy, nuclear magnetic resonance spectrometry and mass spectrometry.
The usual stoichiometry for the reaction is a 1:1 ratio of ylide to acetylene reagent. Of course, an excess of either reagent is permissible. It is preferred that the acetylene reagent be present in excess, and especially preferred that the acetylene be present in a 2:1 excess. Furthermore, the order of addition of either reagent is not critical.

~2~

The regiospecificity of the cycloaadition in Scheme 2 is unpredictable. The stereochemical and electronic properties of the ylide and acetylene and the various reaction conditions have as yet yielded no clearly discernable regiospecific trends. Usually the reaction yields widely varying mixtures of 2,3-regio-isomer products.
The stereospecificity of the cycloaddition of Scheme 3 at the C~ position of the bicyclic pyrazolidinone product is determined by the stereo-chemistry at C4 of the ylide starting material. Thus, i~ the ylide is chiral (either 4-(R) or 4-(S)) then the cycloaddition product will be chiral (7-(~) or 7-(S), respectively). Similarly, a C4 enantiomeric mixture of ylide starting materials will yield a C7 enantiomeric mixture of cycloaddition products.
The compounds produced by Scheme 3 above are the 7-(protected amino) derivatives of Formula'III.
In order to enhance the antimicrobial activity of the bicyclic pyrazolidinone compounds, it is desira~le to replace the amino-protecting group with an acyl group derived from a C1 to C3 o carboxylic acid. As discussed above, the acyl groups employed are typically those used to achieve the same purpose when bonded to the 6-amino group of a penicillin or a 7-amino group of a cephalo-sporin.
The first step for the acylation of a 7-(pro-tected amino) bicyclic pyrazolidinone compound ("7-pro-tected amino nucleus") is the removal of the amino pro-tecting group. The conditions for the removal of thesegroups are well known in the cephalosporin and peni-1~i9~

cillin arts. For example, the trimethylsilyl protecting group is removed by simple hydrolysis, the t-butoxy-carbonyl group is removed by acidic hydrolysis (either trifluoroacetic acid or a mixture of hydrochloric acid in glacial acetic acid), and the allyloxycarbonyl group is removed as a palladium complex.
Removal of the acid-labile amino protecting groups usually yields the 7-amino nucleus as a salt.
The salt of the nucleus is neutralized by conventional procedures before acylation. For instance, the removal of the t-butoxycarbonyl group with trifluoroacetic acid leaves the trifluoroacetate salt of the resultant 7-amino compound. The salt is taken up in tetrahydro-furan and bis(trimethylsilyl)trifluoroacetamide was added to yield the corresponding 7-amino compound.
The (neutralized) 7-amino compound can be isolated then acylated or acylated ln situ. Similarly, the removal of the t-butoxycarbonyl group with a mixture of hydro-chloric acid in acetic acid leaves the hydrochloride salt. The hydrochloride salt is neutralized with a base such as N-methylmorpholine and generally acylated ln SltU
-The methods fGr the acylation of the 7-amino bicyclic pyrazolidinone compounds with the acyl side chain are similar to the methods for the acylation of 6-aminopenicillanic acid, 7-aminodesacetoxycephalosporanic acid and 7-aminocephalosporanic acid. One method is to simply combine the 7-amino nucleus wi-th an acid chloride or acid bromide. The acid chloride or acid bromide may be formed in situ. Another method is to combine the 7-amino nucleus with the free carboxylic acid form of the side chain (or its acid salt) and a condensing agent. Suitable condensing agents include N,N'-disub-stituted carbodiimides such as N,N'-dicyclohexylcarbodi-imide, N,N'-diethylcarbodiimide, N,N'-di-(n-propyl)-carbodiimide, N,N'-di-(iso-propyl)carbodiimide, N,N'-diallylcarbodiimlde, N,N'-bis(p-dimethylaminophenyl)-carbodiimide, N-ethyl-N'-(4''-ethylmorpholinyl)carbodi-imide and the like. Other suitable carbodiimides are disclosed by Sheehan in U.S. Paten-t No. 2,938,892 and by Hofmann et al. in U.S. Patent No. 3,065,224. Azolides, such as N,N'-carbonyldiimidazole and N,N'-thionyldi-imidazole may also be used. Dehydrating agents such as phosphorus oxychloride, alkoxyacetylenes and 2-halogeno-pyridinium salts (such as 2-chloropyridinium methyl iodide, 2-fluoropyridinium methyl iodide, and the like) may be used to couple the free acid or its acid salt with the 7-amino nucleus.
Another acylation method entails first con-verting the free carboxylic acid form (or the corre-sponding salt) of the acyl side chain to the activeester derivative which is in turn used to acylate the nucleus. The active ester derivative is formed by esterifying the free acid form with groups such as p-nitrophenol, 2,4-dinitrophenol, trichlorophenol, pentachlorophenol, N-chlorosuccinimide, N-chloro maleic imide, N-chlorophthalimide, 2-chloro-4,6-dimethoxy-triazene, 1-hydroxy-lH-benzotriazole or l-hydroxy-6-chloro-lH-benzotriazole. The active ester derivatives can also be mixed anhydrides, formed with groups such as methoxycarbonyl, ethoxycarbonyl, iso-butoxycarbonyl, trichloromethylcarbonyl, and iso-but-2-ylcarbonyl and ~X~i91C)~i the carboxylic acid of the side chain. The mixed anhydrides are synthesized by acylating the carboxylic acid of the acyl side chain.
Alternatively, the 7-amino nucleus can be acylated with the N-ethoxycarbonyl-2-ethoxy-1,2-dihydro-quinoline (EEDQ) derivative of the acyl side chain. In general, the free acid form of the acyl side chain and EEDQ are reacted in an inert, polar organic solvent (e.g. tetrahydrofuran, acetonitrile, etc.). The resul-tant EEDQ derivative is used ln situ to acylate the7-amino nucleus.
Once the bicyclic pyrazolidinones are acylated with the appropriate acyl group derived from a Cl to C30 carboxylic acid, they are converted to the corre-sponding antimicrobial final product form by removingany remaining amino, hydroxy and/or carboxy protecting groups on the molecules. As discussed above, such re-moval methods are well known in the cephalosporin, penicillin and peptide arts. Once the carboxy groups are deprotected, the oral ester may be put on the desired carboxy group(s) at R4, R5, R7 and R8. The methods for making the oral ester derivatives are well known in the cephalosporin and penicillin art.
The antimicrobial compounds of Formula III
inhibit the growth of certain organisms pathogenic to man and animals. The antimicrobial compounds are com-pounds wherein the various amino, hydroxy and/or carboxy protecting groups have been removed. The antimicrobial activity can be demonstrated in vitro using standard tube-dilution techniques. The ln vitro tests demon-strate that the 7-(S) antimicrobial compounds are ~2~i~10~

more active than either a mixture of corresponding C7 enantiomers or the corresponding 7-(R) compounds.
Representative pathogens which are sensitive to the antimicrobial compounds of Formula III include Staphylococcus aureus Xl.l, Streptococcus pYogenes C203, Streptococcus pneumoniae Park, Hemophilus influenzae 76 (ampicillin reslstant), Escherichia coll N10, Escherichia coli EC14, Escherichia coli TEM (b-lactamase producer), Klebsiella pneumoniae X26, Klebsiella pneumoniae KAE (~-lactamase producer), Klebsiella pneumoniae X68, Enterobacter aerogenes C32, _ Enterobacter aerogenes EB17, Enterobacter cloacae EB5 (non-~-lactamase producer), Salmonella typhi X514, Salmonella typhi B35, Serratia marcescens X99, Serratia marcescens SE3, Proteus morganii PR15, Proteus -inconstans PR33, Proteus rettgeri C24, Citroboaeter freundii CF17, and the like.
The antimicrobial compounds for which the diazolidinones of this invention are intermediates are useful for the therapeutic or prophylactic treatment of infections in warm-blooded animals caused by both gram-positive, gram-negative and acid-fast bacteria.
The antimicrobial compounds can be admin-istered orally, parenterally (e.g. intravenously, intramuscularly or subcutaneously) or as a topical ointment or solution in treating bacterial infections of warm-blooded animals.
Further description of the synthesis and the properties of the bicyclic pyrazolidinones of Formula III are found in L.N. Jungheim, S.K. Sigmund, C.J.
Barnett, R.E. Holmes and R.J. Ternansby, Canadian Patent ~2~ 0~

Application No. 50~,777, filed April 28, 1986.
The following Examples are provided to further illustrate the invention. It is not intended that the invention be limited in scope by reason of any of the following Preparations or Examples.
In the following Preparations and Examples, the terms melting point, nuclear magnetic resonance spectra, field desorption mass spectra, electron impact mass spectra, infra-red spectra, ultraviolet spectra, elemental analysis, high performance liquid chroma-tography and thin layer chromatography are abbreviated m.p., n.m.r., f.d.m.s., m.s., i.r., u.v., anal., HPLC
and TLC, respectively. In addition, the adsorption maxima listed for the i.r. spectra are only those of interest and not all of the maxima observed.
The abbreviations THF, TFA and BSTFA stand for tetrahydrofuran, trifluoroacetate and N,O-bis-(trimethylsilyl)trifluoroacetamide, respectively.
In conjunction with the n.m.r. spectra, the following abbreviations are used: "s" is singlet, "d"
is doublet, "dd" is doublet of doublets, "t" is triplet, "q" is quartet, "m" is multiplet, "dm" is a doublet of multiplets and "br. s", "br. d" and "br. t" stand for broad singlet, doublet and triplet, respectively. "J"
indicates the coupling constant in Hertz. "DMSO/d6" is dimethyl sulfoxide where all protons have been replaced with deuterium.

1~9~1U~ -The n.m.r. spectra were obtained on a Varian Associates EM-390 90 MHz, on a Jeol FX-9OQ 90 MHz instrument, or on a ~eneral Electric QE-300 MHz instru-ment. The chemical shifts are expressed in ~ values (parts per million downfield from tetramethylsilane).
The field desorption mass spectra were taken on a Varian-MAT 731 Spectrometer using carbon dendrite emitters. Electron Impact Mass Spectra were obtained on a CEC 21-110 instrument from Consolidated Electrodynamics Corporation. Infrared spectra were obtained on a Perkin-Elmer Model 281 instrument. Ultraviolet Spectra were obtained on a Cary Model 118 instrument. Specific rotations were obtained on a Perkin-Elmer Model Q-41 instrument. Thin layer chromatography was carried out on E. Merck silica gel plates. Melting points reported are uncorrected.

Preparation 1 Methyl 3-(p-Toluenesulfonate)-2-(S)-(t-Butoxycarbonylamino~Propionate Methyl (3-hydroxy)-2-(S)-(t-buto~ycarbonyl-amino)propionate (58 g, 196 mmol), dry methylene chlo-ride (150 ml), p-toluenesulfonyl chloride (43.35 g, 227.4 mmol), 4-(dimethylamino)pyridine (2.4 g, 19.6 mmol) and pyridine (30 ml, 371 mmol) were combined and stirred at room temperature overnight. The reaction solution was concentrated in vacuo to a pale yellow oil.
The oil was stored ln vacuo overnight, then the white solid that formed was isolated to give 75.33 g of crude 91~

product. The product was triturated in petroleum ether (approximately 200 ml) to yield methyl 3-(p-toluenesulfo-nate)-2-(S)-~t-butoxycarbonylamino)propionate: n.m.r.:
(CDCl3, 90 MHz): ~ 7.72, 7.31 (2x dd, 4, aromatic protons),

5.26 (m, 1, nitrogen proton), 4.48 (m, 1, C-2 proton), 4.32 (m, 2, C-3 protons), 3.68 (s, 3, methyl protons of methyl ester), 2.44 (s, 3, methyl protons of toluene moiety), 1.40 (s, 9, protons of t-butyl moiety); i.r.
(CHCl3): 3435, 3019, 1753, 1711, 1502, 1369, 1351, 1250, 10 1215, 1190, 1177 cm~1; m.s.: 279, 210, 172, 91, 41;
Anal. Calcd. for C16H23NO7S:
Theory: C, 51.19; H, 6.71; N, 3.73; S, 8.54.
Found: C, 51.05; H, 6.50; N, 3.63; S, 8.13.

Exam_le l 4-(R,S)-(t-Butoxycarbonylamino)-3-Oxo-1,2-Diazolidine Under a nitrogen atmosphere, dry methylene chloride (50 ml) was cooled in an ice bath and anhydrous hydrazine (11.0 g, 333 mmole), (97%) was added. The ice bath was removed and the solution was stirred until it warmed to room temperature. At this time a solution of methyl 3-(p-toluenesulfonate)-2-(S)-(t-butoxycarbonyl-amino)propionate (20.0 g, 53.6 mmole) in dry methylene chloride (50 ml) was gradually added. The reaction solution was stirred under nitrogen at room temperature for 5 hours. The solution was then concentrated under reduced pressure and the concentrate was taken up in saturated aqueous sodium bicarbonate solution. The ~X~i910~;

aqueous solution was continuously extracted for 14 hours with methylene chloride (700 ml). The methylene chlo-ride solution was dried over sodium sulfate, filtered and concentrated under reduced pressure to yield approxi-mately 5.15 g, 48% of 4-(R,S)-(t-butoxycarbonylamino)-3-oxo-1,2-diazolidine: n.m.r. (CDC13, 90 MHz): ~ 7.04 (m, 1), 5.12 (m, 1), 4~28 (m, 1, C-4 proton), 3.94 (m, 1, C-5 proton), 3.20 (m, 1, C-5 proton), 1.45 (s, 9, t-butyl protons); i.r. (CHC13): 3430, 3250, 3019, 2983, 1702, 1545, 1503, 1370, 1297, 1241, 1215, 1165 cm~l;
f.d.m.s.: M = 201;
Anal. Calcd. for C8H15N3O3:
Theory: C, 47.75; H, 7.51; N, 20.88.
Found: C, 47.80; ~, 7.56; N, 20.61.
Example 2 4-(R,S)-(t-Butoxyczrbonylamino)-3-Oxo-1,2-Diazolidine p-Toluenesulfonate Salt 4-(R,S)-(t-Butoxycarbonylamino)-3-oxo-1,2-diazolidine (1.7 g, 8.45 mmol) was slurried in methylene chloride (50 ml). p-Toluenesulfonic acid hydrate (1.6 g, 8.45 mmol) was added to the slurry. After 20 minutes the resultant solid material was collected then dried ln vacuo for approximately 48 hours to yield 2.95 g of colorless 4-(R,S)-(t-butoxycarbonylamino)-3-oxo-1,2-diazolidine p-toluenesulfonate salt: n.m.r. (90 MHz, DMSO-d6): ~ 7.5 (d, 2, J = 8), 7.1 (d, 2, J = 8), 4.32 (m, 1), 3.9 (m, 1), 3.4 (m, 1) 2.3 (s, 3), 1.4 (s, 9);
i.r. (KBr): 1742, 1704, 1537 cm ~ 3 Preparation 2 4~(R,S)-(t-Butoxycarbonylamino)-3-Oxo-1-(Methylene)-1,2-Pyrazolidinium Ylide 4-(R,s)-t-(sutoxycarbon~lamino)-3-oxo-1,2-diazolidine (4.02 g, 20 mmol) was dissolved in dry methanol (50 ml). 37% Aqueous formaldehyde (1.62 g, 20 mmol) was added, the mixture was stirred for 20 minutes at room temperature then concentrated in vacuo.
The solvent was removed by azeotropic distillation with methanol in vacuo at 40C. The resultant residue was dried ln vacuo at 40C overnight to yield 4-(R,S)-(t-butoxycarbonylamino)-3-oxo-1-(methylene)-1,2-pyra-zolidinium ylide: n.m.r. (90 MHz, CDCl3): ~ 6.1-5.3 (m, 2), 4.9-4.2 (m, 6), 4.0-3.6 (m, 2), 3.5-3.1 (m, 2), 1.4 (s, 18); i.r. (KBr): 3379, 2980, 2930, 1705, 1524, 1519, 1504, 1455, 1393, 1368, 1297, 1252, 1166 cm~l;
f.d.m.s.: M = 213.
Preparation 3 2,3-di(Allyl Carboxylate)-7-(R,S)-(t-Butoxy-carbonylamino)-8-Oxo-1,5-Diazabicyclo[3.3.0]Octa-2-ene 4-(R,S)-(t-Butoxycarbonylamino)-3-oxo-1-(methylene)-1,2-pyrazolidinium ylide from Preparation 2 above was dissolved in dry acetonitrile (50 ml) and diallyl butynedioate (3.88 g, 20 mmol) was added. The mixture was heated to reflux for 3 hours then concen-trated _ vacuo. The resultant solid was chromato-graphed by HPLC on silica gel eluted with 2:1 hexane:-ethyl acetate, to yield 2.67 g, 32.8% yield of 2,3-di(allyl carboxylate)-7-(R,S)-(t-butoxycarbonylamino)-8-oxo-1,5-diazabicyclo[3.3.0]octa-2-ene: n.m.r. (90 MHz, CDCl3~: ~ 6.20-5.70 (m, 2, unsaturated protons on allyl groups), 5.52-5.0 (m, 5, C-7 proton and unsaturated protons in allyl group), 4.82 (dm, 2, ~ = 6, unsaturated protons on allyl group on C-2 carboxylate), 4.64 (dm, 2, J = 6, saturated protons on allyl group on C-3 car-10 boxylate group), 4.38 (d, l, J = 13, C-4 proton), 4.04 (t, 1, J = 8, C-6 proton), 3.92 (d, 1, J = 13, C-4 proton), 2.88 (dd, 1, J = 8, 12, C-6 proton), 1.45 (s, 9, protons of t~butyl group); u.v. (methanol): AmaX =
345 ( = 8500); i.r. (CHC13): 3019, 1750, 1736, 1709, 15 1384, 1370, 1278, 1234, 1215, 1162 cm~1;
Anal. Calcd. for C1gH25O7N3:
Theory: C, 56.01; H, 6.19; N, 10.31.
Found: C, 56.24; H, 6.35; N, 10.10.

PreParation 4 2,3-di(Allyl Carboxylate)-7-(R,S)-[2-(Thien-2-yl)Acetamido]-8-Oxo-1,5-Diazabicyclo[3.3.0]0cta-2-ene A. Removal of Amino Protecting Group and Formation of TFA Salt 2,3-di(Allyl carboxylate)-7-(R,S) (t-butoxy-carbonylamino)-8-oxo-1,5-diazabicyclo[3.3.0~octa-2-ene (407 mg, 1 mmol) was dissolved in trifluoroacetic acid (2 ml) and the solution was stirred for 5 minutes then concentrated ln vacuo.

o~i ~. Neutralization of TFA salt The residue from Step A was taken up in THF
(5 ml) and BSTF~ (1.5 ml) was added while the mixture was being cooled to 0C.

C. Acylation of Nucleus A THF solution (1 ml) of 2-(thien-2-yl)acetyl 0 chloride (176 mg, 1.1 mmol) was added to the solution from Step B and the resultant mixture was stirred at 0C for 20 minutes. The reaction mixture was then poured into ethyl acetate and the resulting organic mixture was washed with saturated sodium bicarbonate solution, 0.2N
hydrochloric acid, brine, dried over magnesium sulfate and filtered. The filtrate was concentrated ln vacuo to give 700 mg of crude oily residue. The residue was chromatographed on a silica gel preparatory-scale TLC
plate eluted with 1:1 hexane:ethyl acetate solution to 20 give 270 mg, 62% yield of 2,3-di(allyl carboxylate)-7-(R,S)-[2-(thien-2-yl)acetamido]-8-oxo-1,5-diazabicyclo-[3.3.0]octa-2-ene: n.m.r. (90 MHz, CDC13): ~ 7.22 (m, 1, C-5 proton of thienyl group), 6.96 (m, 2, C-3 and C-4 protons of thienyl group), 6.56 (br. d, 1, J = 6, amido 25 proton), 6.20-5.60 (m, 2, C-2 proton of allyl groups), 5.60-5.10 (m, 4, C-3 (unsaturated) protons of allyl groups), 5.0 (m, 1, C-7 proton), 4.80 (dm, 2, J = 6, C-1 protons of allyl group on C-2 carboxylate group), 4.64 (dm, 2, J = 6, C-1 protons on allyl group on C-3 car 30 boxylate group), 4.36 (d, 1, J = 12, C-4 proton), 4.08 (t, 1, J = 8, C-6 proton), 3.92 (d, 1, J = 12, C-4 proton), - - .
l~i9~

3.80 (s, 2, methylene protons of acetamido group), 2.86 (dd, 1, J = 8, 12, C-6 proton); u.v. (methanol): AmaX =
340 ( = 6850), 230 ( - 12,500); m.s.: M~ = 431; i.r.
(CHCl3): 1750, 1705 cm Anal. Calcd. for C20H22N3O6S:
Theory: C, 55.68; H, 4.91; N, 9.74; s, 7.43.
Found: C, 55.97; H, 5.21; N, 9.52; S, 7.23.

_reparation 5 2,3-di(Carboxylic Acid)-7-(R,S)-[2-(Thien-2-yl)Acetamido]-8-Oxo-1,5-Diazabicyclo[3.3.0]Octa-2-ene Triphenylphosphine (35 mg, 0.13 mmol) was added to a solution of palladium(II) acetate (6 mg, 0.026 mmol) in acetone (3 ml). The mixture was stirred until a white precipitate formed (10 minutes). An acetone solution (3 ml) of 2,3-di(allyl carboxylate)-7-(S)-[2-(thien-2-yl)acetamido]-8-oxo-1,5-diazabicyclo-[3.3.0]octa-2-ene (200 mg, 0.46 mmol) was added to the mixture. After the resultant mixture became homo-geneous, it was cooled to 0C and tri(n-butyl)tin hydride (0.27 ml, 1 mmol) was added. The solution was stirred at 0C for 30 minutes. lN Hydrochloric acid (l ml) was added and the solution was stirred for an additional 10 minutes. The solution was filtered, diluted with water (30 ml), then extracted with he~ane (4 X, 50 ml).
The aqueous phase was separated and freeze-dried to give 170 mg of yellow powder. The powder was triturated with ethyl acetate, sonicated, centrifuged, and the recovered solid was dried ln vacuo to give 2,3-di(car-boxylic acid)-7-(R,S)-[2-(thien-2-yl)acetamidol-8-oxo-1,5-diazabicyclo[3.3.0]octa-2-ene: n.m.r. (90 MHz, acetone-d6): ~ 7.20 (m, 1, C-5 proton of thienyl group),

6.94 (m, 2, C-3 and C-4 protons of thienyl group), 5.2-4.6 (m, 2, acetamido nitrogen proton and C-7 proton), 4.~4 (d, l, J = 13, c-4 proton), 4.0-3.8 (m, 2, side chain methylene proton), 3.80 (s, 2, a C-6 proton and a C-4 proton), 3.0 (dd, 1, J = 8, 12, a C~6 proton); u.v.
(methanol): AmaX = 345 ( = 4000), 226 ( = 7000)i f.d.m.s.: (M~1)+ = 352; i.r. (KBr): 1730, 1699, 1533, 1438, 1405, 1377, 1338, 1246, 1209, 1188 cm 1.

Preparation 6 N-(t-Butoxycarbonyl) (L)-Serine Trifluoroacetyl Acyl Hydrazide N-(t-Butoxycarbonyl) (L)-serine acyl hydrazide (32.85 g, 150 mmol) was suspended in ethanol (400 ml).
Ethylthio trifluorothioacetate (30 ml, 37.02 g, 234.3 mmol) was added to the suspension and the resultant mixture was stirred at room temperature for 65 hours.
The solvent was removed ln vacuo and the residue was dissolved in diethyl ether (160 ml). A seed crystal was added to the diethyl ether solution and the resultant crystals were collected by filtration (approx. 27 g).
The filtrate was evaporated ln vacuo and diethyl ether (50 ml) was added to the residue. The solids that formed on standing were removed by filtration to yield approximately 16.5 g of additional product. The two batches of solids collected by filtration were combined 12tj9~0~

and recrystallized from diethyl ether (3 liters). After effecting solution, the solution was reduced to approx-imately 450 ml to yield (after a second crop) 41.04 g, 87% yieid of N-(t-butoxycarbonyl) (L)-serine trifluoro-acetyl acyl hyrdrazide: n.m.r. (300 MHz, DMSO-d6): ~
11.5 (br. s, 1), 10.33 (s, 1), 6.84 (d, 1, J=9), 4.9 (t, 1, J=7, (OH)), 4.1 ~m, 1), 3.59 (br. m, 2), 1.4 (s, 9);
specific rotation: [~]D5 = ~ 25.87 (10.05 mg/ml in methanol); m.p. 143-144C (first crop), 142-144C
(second crop).
Anal. Calcd. for C1oH16N3O5F3:
Theory: C, 38.10; H, 5.12; N, 13.33;
Found: C, 38.34; H, 4.89; N, 13.16.

Example 3 4-(S)-(t-Butoxycarbonylamino)-1-(Trifluoro-acetyl)-3-Oxo-1,2-Diazolidine N-(t-Butoxycarbonyl) (L)-serine trifluoro-acetyl acyl hydrazide (3.78 g, 12 mmol) and triphenyl-phosphine (3.46 g, 13.2 mmol) were dissolved in THF (50 ml). To the solution was added a THF solution (10 ml) of 95% diethyl azodicarboxylate (2.42 g, 2.19 ml, 13.2 mmol). The resultant mixture was stirred at room temperature for six hours and then the solvent was removed ln vacuo. The residue was dissolved in ethyl acetate (100 ml) and then the solution was washed with aqueous sodium bicarbonate solution (33 ml, 3X). The sodium bicarbonate extracts were combined, aqueous saturated brine solution (70 ml) was added and the ;91~i resultant mixture was extracted with ethyl acetate (120 ml, 3X). The sodium bicarbonate solution was then layered with additional ethyl acetate (200 ml) and lN
hydrochloric acid (approx. 80 ml) was added until the sodium bicarbonate solution had a pH of 2.5. The ethyl acetate layer was separated and the aqueous layer was extracted with additional ethyl acetate (4X, 125 ml).
The ethyl acetate extracts were combined, washed with saturated aqueous brine (125 ml, 2X), dried over sodium sulfate, filtered, and taken to dryness 1n vacuo. The resultant residue was dissolved in acetonitrile (100 ml) then the acetonitrile was removed ln vacuo. Treatment of the residue with acetonitrile was repeated to yield 3.06 g, 96% yield of 4-(S)-(t-butoxycarbonylamino)-1-(trifluoroacetyl)-3-oxo-1,2-diazolidine: n.m.r. (300 MHz, CDCl3): ~ 5.25 (d, 1, J=6), 4.81 (t, 1), m 4.6 (m, 1), 4.06 (t, 1), 1.46 (s, 9); i.r. (CHC13): 1722, 1682, 1518 cm 1; (f.d.m.s.) (m/e): M = 297; specific rotation: [~]D5 = -88.14 (10.03 mg/ml in methanol);
Anal. Calcd for C1oH14N3O4F3:
Theory: C, 40.41; H, 4.75; N, 14.14.
Found: C, 40.58; H, 5.01; N, 13.92.

Example 4 4-(S)-(t-Butoxycarbonylamino)-3-Oxo-1,2 Diazolidine 4-(S)-(t-butoxycarbonylamino)-1-(trifluoro-acetyl)-3-oxo-1,2-diazolidine (2.97 g, 10 mmol) was 310~

X-671lA -35-suspended in water (30 ml), lN sodium hydroxide solution (20 ml, 0.8 g, 20 mmol, pH 12.2) was added and the resultant mixture was stirred for one hour at room temperature. The pH of the mixture was adjusted to

7.2 by the addition of lN hydrochloric acid (10 ml).
Sodium chloride (13 g) was added to the solution and the mixture was extracted with chloroform (50 ml, 8X). The chloroform extracts were combined, washed with saturated aqueous sodium chloride solution (75 ml), dried over sodium sulfate, filtered, and evaporated to dryness 1n vacuo. Diethyl ether (100 ml) was added to the residue and then the ether was removed ln vacuo to yield 0.798 g of a white solid of 4-(S)-(t-butoxycarbonyl-amino)-3-oxo-1,2-diazolidine: n.m.r. (300 MHz, DMSO-d6): ~ 9.23 (s, 1), 7.04 (d, 1, J=9), 5.24 (br. s, 1,), 4.24 (m, 1), 3.41 (t, 1), 2.88 (t, 1), 1.38 (s, 9); specific rotation: [~]D5 = ~ 74.16 (10.06 mg/ml in methanol); (the compound was dried overnight at 80C
before analysis):
Anal. Calcd. for C8H15N3O3:
Theory: C, 47.75; H, 7.51; N, 20.88.
Found: C, 47.75; H, 7.46; N, 20.62.

Procedure 8 2-(Allyl Carboxylate)-3-(Methyl Carboxylate)-7~(S)-(t-Butoxycarbonylamino)-8-Oxo-1,5-Diazabicyclo-[3.3.0]Octa-2-ene 1~6910~

Step 1 Formation of Pyrazolidinium Ylide 4-(S)-(t-butoxycarbonylamino)-3-oxo-1,2-diazolidine (20.1 g, 100 mmol) was suspended in 1,2-dichloroethane (400 ml), 37% aqueous formaldehyde solution (8.51 ml, 3.15 g, 105 mmol) was added and the resultant mixture was stirred at room temperature for 1.5 hours.

Step 2 15 Cycloaddition of Acetylene Allyl methyl butynedioate (18.48 g, 110 mmol) was added to the mixture from Step 1 and the resultant mixture was refluxed for 6.5 hours. The volume of the reaction mixture was reduced by half in a flask fitted with a Dean-Stark trap. Hexane (200 ml) was added and the mixture was allowed to stand until an oil formed.
The solvent was decanted, the oil was dissolved in ethyl acetate (300 ml) and the solution was taken to dryness ln vacuo to yield 17.3 g of a foam. The foam was chromatographed using preparatory-scale high performance liquid chromatography using a silica column eluted with a gradient of 0 to 40% ethyl acetate in isooctane (8 liters). The product-containing fractions were combined to yield 1.456 g of a yellow solid. The solid was recrystallized from a mixture of ethyl acetate and 1~910~

hexane to yield 0.55 g of 2-(allyl carboxylate)-3-(methyl carboxylate)-7-(S)-(t-butoxycarbonylamino)-8-oxo-1,5-diazabicyclo[3.3.0]octa-2-ene: n.m.r. (300 MHz, CDC13): ~ 6.00 (m, 1), 5.38 (m, 2), 5.1 (br. d, J=6), 4.86 (d, 2), 4.74 (m, 1), 4.37 (d, 1, J=13), 4.08 (t, 1), 3.91 (d, 1, J=13), 3.77 (s, 3), 2.86 (t, 1), 1.46 (s, 9); i.r. (KBr): 1751, 1710, 1687 cm 1; u.v.
(ethanol): AmaX = 346 (~max = 8489); f-d-m-s- (m/e) M = 381; specific rotation: [~]Ds = _ 481.92 (10.01 mg/ml in methanol); m.p. 111-113~C; Anal. Calcd for Theory: C, 53.54; H, 6.08; N, 11.02.
Found: C, 53.83; H, 6.06; N, 10.77 Procedure 9 2-(Allyl Carboxylate)-3-(Methyl Carboxylate)-7-(S)-Amino-8-Oxo-1,5-Diazabicyclo[3.3.0]0cta-2-ene Hydrochloride Salt 2-(Allyl carboxylate)-3-(methyl carboxylate)-7-(S)-(t-butoxycarbonylamino)-8-oxo-1,5-diazabicyclo-[3.3.0]octa-2-ene (0.1905 g, 0.5 mmol) was added to 3 M
hydrochloric acid in glacial acetic acid (7 ml) and the resultant mixture was stirred at room temperature for five minutes then taken to dryness ln vacuo. The resultant yellow solid was dissolved in methylene chloride (20 ml) and the mixture was sonicated and evaporated ln vacuo. The methylene chloride/sonication procedure was repeated two more times. The solid was dried ln vacuo for 1.5 hours to yield to 2-(allyl carboxylate)-3-(methyl carboxylate)-7-(S)-amino-8-oxo-1,5-diazabicyclo[3.3.0]octa-2-ene hydrochloride salt.

Procedure 10 2-(Allyl Carboxylate)-3-(Methyl Carboxylate)~
7-(S)-[2-(2-(Allyloxycarbonylamino)Thiazol-4-yl-2-~Z)-(Methoxyiminoacetamido)]-8-Oxo-1,5-Diazabicyclo [3.3.0]Octa-2-ene Under a nitrogen atmosphere, 2-[2-(N-allyloxy-carbonylamino~thiazolo-4-yl]-2-(z)-methoxyiminoacetic acid (0.1425 g, 0.5 mmol) was suspended in dried methylene chloride (5 ml). The suspension was cooled to 0C then 6-chloro-2,4-dimethoxy-1,3,5-triazine (0.088 g, 0.5 mmol) and N-methylmorpholine (0.0505 g, 0.5 mmol) were added. The resultant solution was stirred at 0C
for forty minutes. Additional N-methylmorpholine (0.0505 g, 0.5 mmol) and then a methylene chloride suspension (5 ml) of 2-(allyl carboxy)-3-(methyl carboxylate)-7-(S)-amino-8-oxo-1,5-diazabicyclo[3.3.0]-octa-2-ene hydrochloride salt (0.5 mmol) were added.
After all the solid dissolved, the solution was stirred at room temperature for 20 hours then evaporated to dryness in vacuo. The residue was dissolved in ethyl acetate ~70 ml) and water (15 ml), the layers were separated, and the ethyl acetate was extracted sequen-tially with 0.1N hydrochloric acid (10 ml, 3X), satu-rated aqueous sodium bicarbonate solution (20 ml, 3X), brine solution (20 ml, 3X), dried over sodium sulfate, filtered, and evaporated to dryness ln vacuo to yield 280 mg of a yellow solid. The solid was recrystal-lized from a mixture of methylene chloride and di(iso-propyl) ether to ~ield 136 mg of the 2-(allyl ;9~

carboxylate)-3-(methyl carboxylate)-7-(S)-L2-(2-(t-allyl-oxycarbonylamino)thiazol-4-yl)-2-(Z)-methoxyimino~
acetamido)]-8-oxo-1,5-diazabicyclo[3.3.0]octa-2-ene:
n.m.r. (300 MHz, DMSO-d6): ~ 12.1 (s, 1), 9.32 (d, 1, J=9), 7.43 (s, 1), 5.94 (m, 2), 5.34 (m, 4), 5.09 (m, 1), 4.83 (d, 2, J=6), 4.7 (d, 2, J=6), 4.31 (d, l, J=13), 4.02 (d, 1, J=13), 3.88 (overlapping t and s, 4), 3.69 (s, 3), 3.18 (t, 1); u.v. (ethanol)i ~max = 342 (~max = 8680), 264 (13,626), 209 (25,137); f.d.m.s.
(m/e): M = 548, 490; specific rotation: [~]D5 =
-351.45 (10.01 mg/ml in methanol).
Anal. Calcd for C22H24N6OgS:
Theory: C, 48.17; H, 4.41; N, 15.32.
Found: C, 48.09; H, 4.41; N, 15.02.
Procedure 11 2-(Carboxylic Acid)-3-(Methyl Carboxylate)-7-(S)-[2-(2-Aminothiazol-4-yl)-2-(Z)-Methoxyiminoacetamido]-

8-Oxo-1,5-Diazabicyclo[3.3.0]0cta-2-ene Hydrate Palladium(II) acetate (18 mg, 0.08 mmol) was suspended in acetone (4 ml). Triphenylphosphine (105 mg, 0.4 mmol) was washed into the suspension with additional acetone (2 ml) and the resultant mixture was stirred at room temperature for 20 minutes. 2-(Allyl carboxylate)-3-(methyl carboxylate)-7-(S)-[2-(2-(allyloxy-carbonylamino)thiazol-4-yl)-2-(Z)-methoxyiminoacetimido]-8-oxo-1,5-diazabicyclo[3.3.0]octa-2-ene (0.497 g, 0.9096 mmol) was suspended in a mixture of acetone (45 ml) and 1~i9 1V~

acetonitrile (15 ml~ was then added to the reaction suspension. The suspension was stirrea at room tem-perture for 35 minutes then cooled to 0C. Tri(n-butyl)tin hydride (0.548 g, 1.81 mmol, 0.506 ml) was slowly added to the cooled suspension and the mixture was stirred at 0C for 30 minutes then at room tem-perature for 50 minutes. The mixture was cooled to 0C then lN hydrochloric acid (1.82 ml, 1.81 mmol) was added. The resultant mixture was stirred at 0C for 10 minutes then at room temperature for 5 minutes. The mixture was filtered, water (130 ml) was added to the filtrate, and the resultant mixture was filtered through a pad of CeliteTM. The filtrate was extracted with hexane (4X, 40 ml), and the aqueous layer was filtered through a pad of Celite~ then reduced ln vacuo to about 75% volume. The resultant yellow solid was recovered by filtration through a pad of Celite~ and the filtrate was extracted with ether (2X, 75 ml), concentrated ln vacuo to remove any residual ether and the resultant yellow solution was lyophilized. The lyophilized solid was dissolved in water (75 ml), filtered and chromatographed on a preparatory-scale high performance liquid chromato-graph using a C18 reverse phase column eluted with a gradient of 0 to 10% methanol/0.5% acetic acid/water (8 liters) then a gradient of 10 to 25% methanol/0.5%
acetic acid/water (8 liters) to yield 91.5 mg of 2-(carboxylic acid)-3-(methyl carboxylate)-7-(S)-[2-(2-aminothiazol-4-yl)-2-(Z)-methoxyiminoacetamido]-8-oxo-1,5-diazabicyclo[3.3.0~octa-2-ene: n.m.r. (300 MHz, DMSO-d6): ~ 9.18 (d, 1, J=lO), 7.24 (br- s, 2), 6.94 (s, l), 5.02 (m, l), 4.23 (d, 1, J=13), 3.9 (d, 1, J=13), 3.8 (overlapping t and s, 4), 3.1 (t, 1); i.r.
(KBr): 1726, 1688, 1670.5 cm 1; u.v. (ethanol~: AmaX=328 (maX=10,950~, 233 (16,013); f.d.m.s. (m/e): M
425; specific rotation: [~]Ds = -326.35 (9.83 mg/ml in methanol);

Anal. Calcd f r 15 16 6 7 2 Theory: C, 40.72; H, 4.10; N, 19.00 Found: C, 40.81; H, 3.70; N, 19.03.

Claims (15)

X-6711A-(Canada) -42-The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for preparing a compound of Formula (I):

wherein:
R1 and R2 are a) taken together to form a phthalimido group; or b) either R1 or R2 is hydrogen and the other of R1 or R2 is an amino-protecting group; and R3 is hydrogen or trihaloacetyl;
or an acid-addition salt thereof; which comprises:
(A) reacting a compound of Formula with hydrazine, wherein Z is an amino-protecting group and L is a leaving group; or (B) deacylating a compound of Formula (I) where R3 is trihaloacetyl; or X-6711A-(Canada) -43-(c) ring closing a compound of formula:

wherein Z is an amino protecting group and R3 is tri-halo acetyl; and when desired, forming an acid addition salt of the compound of Formula (I) so prepared.

2. A process according to claim 1, wherein R3 is hydrogen.

3. A process according to claim 1, wherein R3 is trifluoroacetyl.

4. A process for preparing a compound of Formula (IV):

(IV) wherein R1, R2 and R3 are as defined in claim 1, or an acid addition salt thereof; which comprises deacylating a compound of formula:

wherein R3 is trihaloacetyl; or X-6711A-(Canada) -44-ring closing a compound of formula:

5. A process according to claim 4, wherein R3 is trifluoroacetyl.

6. A compound of Formula (I)as defined in claim 1, whenever prepared by a process as claimed in claim 1, or by an obvious chemical equivalent thereof.

7. A compound of Formula (IV) as recited in claim 4, whenever prepared by a process as claimed in claim 4 or by an obvious chemical equivalent thereof.

8. A compound of Formula (I):

I

wherein:
R1 and R2 are a) taken together to form a phthalimido group; or b) either R1 or R2 is hydrogen and the other of R1 or R2 is an amino-protecting group; and R3 is hydrogen or trihaloacetyl or an acid-addition salt thereof.

9. A compound according to claim 8, wherein R3 is hydrogen.

X-6711A-(CAN) -45-

10. A compound according to claim 8, wherein either R1 or R2 is hydrogen and the other is t-butoxycarbonyl.

11. A compound according to any one of claims 8 to 10 wherein R3 is trifluoroacetyl.

12. A compound of Formula (IV):

(IV) wherein R1, R2 and R3 are as defined in claim 8 or an acid-addition salt thereof.

13. A compound according to claim 12,wherein R3 is hydrogen.

14. A compound according to claim 12,wherein R3 is trihaloacetyl.

15. A compound according to claim 12,wherein R3 is trifluoroacetyl.