A chromogenic compound having the structural formula ##STR1## wherein R.sup.1 and R.sup.2 each represent an alkyl group;R.sup.3 and R.sup.4 each represent a hydrogen atom, a halogen atom, an alkyl group, a nitro group, an amino group, an acyl group, or a carboalkoxy group;R.sup.5 represents a hydrogen atom or an alkyl group, with the proviso that R.sup.5 represents an alkyl group only when R.sup.4 represents a hydrogen atom;R.sup.6 represents an alkyl group, an aryl group or an aralkyl group; andX 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.The aforesaid compound may be provided in a pressure-sensitive copy system wherein a visible image is formed upon reaction of the above chromogenic compound with an electron-accepting material of the Lewis acid type.