Process for the preparation of 3-substituted thiophenes.

摘要

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 (1):
<Chemistry id="chema01" num="0001"><Image id="ia01" he="21" wi="74" file="IMGA0001.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>where R' represents a carboxylic acid group, or an ester or amide thereof or a nitrile group; R' represents a group suitable for use as an a-substituent in the side- chain of a penicillin or cephalosporin; which comprises treating under basic conditions a compound of formula [II]:
<Chemistry id="chema02" num="0002"><Image id="ia02" he="19" wi="69" file="IMGA0002.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>wherein X represents halogen or optionally functionalised hydroxyl, Y represents halogen, hydroxyl, or alkoxy; with a source of nucleophilic sulphur ionically bound to a polymeric support.