CARBOSTIRILE DERIVATIVES THAT SERVE TO INHIBIT THE ERYTHEMA AND / OR THE PIGMENTATION OF THE SKIN.

摘要

A carbostyril derivative or salt thereof represented by the general formula (1), (1) (where the hydroxy group is replacing position 5 of the carbostyril skeleton; R1 is a hydrogen atom, a lower alkyl group having 1 to 6 carbon atoms or a lower alkenyl group having 2 to 6 carbon atoms; R2 is a hydrogen atom, a lower alkyl group having 1 to 6 carbon atoms, a lower alkoxy group having 1 to 6 6 carbon atoms, a lower alkenyloxy group having 2 to 6 carbon atoms, a lower alkenyl group having 2 to 6 carbon atoms or a tetrahydropyranyloxy group; R3 and R4 are the same or different from each other and are groups lower alkyl having 1 to 6 carbon atoms that can have hydroxyl groups as substituents; in addition R3 and R4 can form, together with the adjacent nitrogen atom, even with or without a nitrogen atom, sulfur atom or oxygen atom ad icional, a saturated 5- or 6-membered heterocycle group that may have substituents selected from the group consisting of a lower alkyl group having 1 to 6 carbon atoms and a lower alkanoyl group having 1 to 6 carbon atoms; the carbon-carbon bond between positions 3 and 4 of the carbostyle skeleton is a single bond or double bond; with the proviso that when R3 and R4 are lower alkyl groups at the same time, then R2 will be neither a hydrogen atom, nor a lower alkyl group nor a lower alkoxy group).