3-(1,3-dithiol-2-ylidene)-2,4-dioxopyrrolidines, -piperidines, and -hexahydroazepines and use thereof against hepatic diseases

摘要

Novel thioketene derivatives of the formula: <IMAGE> (I) wherein R1 is hydrogen atom, an alkyl group, a lower alkenyl group, a phenyl group or a group of the formula: -B-Y; Y is a nitrogen-containing monocyclic heterocyclic group or a substituted or unsubstituted phenyl group; B is a straight or branched lower alkylene group; R2 and R3 are both a lower alkyl group or are combined together to form a group of the formula: -CH2CH2- or -CH=CH-; R4 is hydrogen atom, a lower alkyl group or a (lower alkoxy)carbonyl group; A is a group of the formula: -(CH2)n- or -CH(COOR5)-; n is an integer of 0, 1 or 2 and R5 is a lower alkyl group, are disclosed. The compound (I) is useful as an agent for treating and protecting various liver diseases.