| 摘要 |
A chromogenic compound having the structural formula <IMAGE> wherein R1 and R2 each represent an alkyl group; R3 and R4 each represent a hydrogen atom, a halogen atom, an alkyl group, a nitro group, an amino group, an acyl group, or a carboalkoxy group; R5 represents a hydrogen atom or an alkyl group, with the proviso that R5 represents an alkyl group only when R4 represents a hydrogen atom; R6 represents an alkyl group, an aryl group or an aralkyl group; and X and Y each represent a hydrogen atom, a halogen atom, a nitro group, a lower alkyl group, an aryl group, an alkoxy group or a carboalkoxy group. |
