(Benzo[4, 5]cyclohepta[l, 2‐b]thiophen‐4‐ylidene)acetic Acids: Novel Non‐ulcerogenic Antiinflammatory Agents

Abstract

AbstractCompound (Z)‐8a has been found to display interesting antiinflammatory activity. In order to prepare derivatives with a wide variety of substituents in the aromatic part of the molecule, a new synthesis of the key intermediates 9a‐g was developed starting from thiophene‐3‐carboxylic acid (11) and substituted benzyl bromides. The conversion of 9a‐g to 10a‐g follows a known procedure. Ketones 10a‐g, on reaction with alkyl (dialkoxy‐phosphoryl)acetate, followed by isomer separation and alkaline ester hydrolysis, yielded the desired derivatives (Z)‐8a‐g and (E)‐8a‐g. The biologically most interesting compound (Z)‐8a is currently undergoing clinical trials.