Carboxylic acid derivative

摘要

Carboxylic acid derivatives having potent retinoid-type pharmacological activities are disclosed. The compounds disclosed are represented by the following formula: <IMAGE> wherein R1, R2, and R3 independently represent a hydrogen atom or an alkyl group with the exception that all of R1, R2, and R3 do not simultaneously represent hydrogen atoms and R1 together with R2 optionally represent a cyclic structure formed by the combination thereof; R4 represents a hydrogen atom or an alkyl group; X represents a nitrogen atom or C-OH; and A represents -CO-NH- or -NH-CO-.