Acetic acid derivatives and composition containing the same

摘要

Novel acetic acid derivatives of the formula: (I) wherein X is oxygen or sulfur; R1 is hydrogen or a lower alkyl; R2 is hydroxy, an alkoxy, an alkenyloxy, a cycloalkyloxy, an aryloxy, a substituted aryloxy, an aryl-lower alkoxy, a substituted aryl-lower alkoxy, an aryl-lower alkenyloxy, a substituted aryl-lower alkenyloxy, an omega -disubstituted amino-lower alkoxy, a lower alkoxycrbonyl-lower alkoxy, a lower alkoxy-lower alkoxy, a hydroxy-lower alkoxy-lower alkoxy, an acyl-lower alkoxy, or a group wherein R3 is hydrogen, hydroxy, a lower alkyl, an aryl-lower alkyl, a hydroxy-lower alkyl, or a carboxy-lower alkyl, R4 is hydrogen, a lower alkyl or a hydroxy-lower alkyl, or the R3 and R4 may combine together with the nitrogen atom to which they are joined to form a heterocyclic group; and the group -CH(R1)COR2 is joined to the carbon atom at 2- or 3-position, and pharmaceutically acceptable salts thereof, processes for their preparation, and pharmaceutical compositions containing these compounds. They have excellent anti-inflammatory, analgesic and antipyretic activities with weak ulcerogenicity in the gastrointestinal tract and toxicity.