Patent GB-1377198-A (GB)
Title: Thia-heterocyclic compounds
IPC: C07D513/04
Filed: 1971-11-03
Abstract: 1377198 2- Thiacepham - 4- carboxylic acids and derivatives CIBA-GEIGY AG 3 Nov 1971 [3 Nov 1970] 51137/71 Heading C2C Novel compounds of the Formula (I): in which R<SP>a</SP> 1  is a hydrogen atom or an aminoprotective group R<SP>A</SP> 1 , and R<SP>b</SP> 1  is a hydrogen atom or R<SP>a</SP> 1  + R<SP>b</SP> 1  represents an organic ylidene radical, R 2  denotes a hydrogen atom or an organic radical R<SP>A</SP> 2  which, together with the -CO-O- grouping, forms an esterified carboxyl group, R 3  is a hydrogen atom or an organic radical linked through a carbon atom and each of the groups R a  and R b  stands for a hydrogen atom or R a +R b  form a covalent carbon-tocarbon bond, or their S-oxides or salts, may be obtained by a process wherein a compound of Formula (II): in which X is an optionally substituted methylene group; R<SP>1</SP> 0  is a hydrogen atom or an organic radical eliminable under the reaction conditions, and R<SP>B</SP> 2  is a radical R<SP>A</SP> 2  or an organic silyl or stannyl radical, or a tautomer or salt thereof is oxidized, or an S-monoxide of a bistrans-trans-disulphide compound of the Formula (III): in which Ac<SP>0</SP> 1  represents an acyl radical eliminable under the reaction conditions, is treated with an acidic reagent and, if desired, in a resulting compound of Formula I, in which R<SP>a</SP> 1  + R<SP>b</SP> 1  form an organic ylidene radical, this radical is eliminated and/or in a resulting compound the amino group possibly substituted by an organic ylidene radical is protected and/or, if desired, in a resulting compound a grouping of the formula -C(=O)-O-R<SP>B</SP> 2  is converted into the free carboxyl group or into an ester grouping of the formula -C(=O)-O-R<SP>A</SP> 2  and, if desired, in a resulting compound a free carboxyl group is converted into an esterified carboxyl group of the formula-C(= O)-O-R<SP>A</SP> 2  and/or, if desired, a resulting compound is converted into an S-oxide and/or, if desired, a resulting compound containing a salt-forming group is converted into a salt or a resulting salt is converted into the free compound or into another salt and/or, if desired, a resulting isomer mixture is separated into the individual isomers. Intermediates of Formula (II) are obtained by reacting a phosphoranylidene compound of the Formula IV): in which Ac<SP>0</SP> 2  is an easily eliminable acyl radical and R<SP>a</SP> 0 , R<SP>b</SP> 0  and R<SP>c</SP> 0  each represent a substituted or unsubstituted hydrocarbon radical, with an aldehyde of the formula R 3 CHO to form a compound of Formula (VI): which is further reacted with R<SP>2</SP> 0 SH to form a compound of Formula VIIIa (which corresponds to II in which R a  and R b =H and is substituted on the N by Ac<SP>0</SP> 2 ). Ac<SP>0</SP> 2  can then be replaced by H in known manner. Compound VIIIa can be converted to a compound (IX): in which Ac<SP>1</SP> 0  is the acyl radical of an organic carboxylic acid, then the group Ac<SP>1</SP> 0 O can be eliminated by treatment with a basic reagent or with a reducing agent to yield (VIIIb): Compounds II in which R a +R b  is a C-C bond can also be obtained by photolysis of VIIIa in the presence of a basic reagent. If the photolysis is followed by, or carried out in the presence of, an oxidant, a disulphide of the Formula (IIIa) can be obtained (where IIIa is like III but containing R<SP>A</SP> 2  instead of R<SP>B</SP> 2  and Ac<SP>0</SP> 2  instead of Ac<SP>0</SP> 1 ). IIIa can be converted to a corresponding S-monoxide by treatment with an appropriate oxidant. Treatment of a compound VIIIa with diphenyldiazomethane with irradiation leads to, for example, α - (3,3- dimethyl - 7 - oxo - 2 - tert. - butoxycarbonyl- 4 - thia - 2,6 - diaza - 6 - bicyclo[3.2.0]heptyl)- α - (3,3 - diphenyl - 2 - thiacyclopropyl) - acetic acid tert.-butyl ester. Pharmaceutical compositions suitable as antibiotically active medicaments comprise a compound of the Formula I in admixture or eonjunction with a pharmaceutically suitable carrier in forms suitable for enteral or parenteral administration.