Process for prepn. of 2-benzoyl:benzoic acid derivs. - by reaction between substd. 3,3-di:phenyl:phthalide(s), lower alkanoic acids and water

摘要

Process for the prepn. of a 2-benzoylbenzoic acid deriv. of formula (I) comprises reacting a phthalide deriv. with a lower-alkanoic acid and water. In (I) and (II), R1,R2,R3 and R4 are the same or different non-tert. lower alkyl, Y is H and Z is NR3R4 or Y is non-tert. lower alkyl, non-tert. lower alkoxy or di-lower-alkyl amino and 2 is di-lower alkylamino. The process provides cpds. which are useful intermediates for preparing valuable chromogenic phthatide cpds. e.g. the 3,3-diaryl phthalides (U.S.Pat Nos. Re23,024 and 4,096,176) which are useful in pressure-sensitive carbonless duplicating systems and thermal marking systems.