Chemical process
AssigneeBeecham Group Limited
InventorsKenneth T. Veal, Trevor J. Grinter
Life of this patent
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Abstract
An improved process for the preparation of 3-substituted thiophenes. The thiophenes are useful for the preparation of penicillins and cephalosporins. The process is for the preparation of a thiophene of formula (I): ##STR1## where R.sup.1 represents a carboxylic acid group, or an ester or amide thereof or a nitrile group; R.sup.2 represents a group suitable for use as an .alpha.-substituent in the side-chain of a penicillin or cephalosporin; which comprises treating under basic conditions a compound of formula (II): ##STR2## wherein X represents halogen or optionally functionalized hydroxyl, Y represents halogen, hydroxyl, or alkoxy; with a source of nucleophilic sulphur ionically bound to a polymeric support.
Claims9
A process for the preparation of a thiophene of formula (I):
- ##STR6## wherein R.sup.1 represents a carboxylic acid group or an ester or amide derivative thereof or a nitrile group;
- and R.sup.2 represents hydrogen, a hydrocarbon or heterocyclic group, a carboxylic acid group or an ester of amide derivative thereof;
- or an acyl, nitrile, isonitrile or optionally substituted imine group of formula --CH.dbd.NZ or --N.dbd.CHZ where Z represents hydrogen, alkyl or aryl, or a sulphonyl, --SR.sup.a, sulphoxide --SO.R.sup.a or sulphonate --SO.OR.sup.a group wherein R.sup.a represents C.sub.1-6 alkyl, or aryl, which process comprises treating a compound of formula (II):
- ##STR7## wherein R.sup.1 and R.sup.2 are as defined with respect to formula (I) above;
- X represents a halogen atom, a hydroxyl group or a functionalised hydroxyl group;
- Y represents a halogen atom, a hydroxyl group, or an alkoxy group;
- under basic conditions with a source of nucleophilic sulphur ionically bound to a polymeric support which is insoluble in the reaction solution.
Dependencies are inferred from the claim text.