UN PROCEDIMIENTO PARA PREPARAR ACIDOS 2-(ALFA,ALFA-ARIL-YNO HETERIL DISUSTITUIDO)-METILBENZOICOS.

摘要

Compounds of formula III are prepared by condensation of the corresponding lactone (phthalide) with a compound H-Z with opening of the lactone ring. The symbols employed are explained in Claim 1. The compounds obtained can be converted by oxidation of the compound III to re-form the lactone. The compounds described are employed as colour-generating substances in a duplication system without carbon paper.