Hydrochloric Acid → 3,3-Bis(2,4-bis(dimethylamino)phenyl)phthalide

Participants

Reaction Steps

A mixture of crude 2-(2,4-bis(dimethylamino)-benzoyl)benzoic acid (7 g.), N,N,N' ,N'-tetramethyl-m-phenylenediamine (1.64 g.) and acetic anhydride was warmed (at 25°-35° C.) during two to three hours, then poured into dilute hydrochloric acid (10%). The resulting mixture was basified and filtered with a filter aid. The filter cake was extracted with hot toluene. Dilution of the toluene extract with hexane afforded 3,3-bis(2,4-bis(dimethylamino)-phenyl)phthalide (I: X=Y2 = Y4 = (CH3)2N, Z4 = Z5 = Z6 = Z7 = H) (m.p. 186°-188° C.).

Provenance & Evidence