Acetic Anhydride → 3-(2,4-Bis(diethylamino)phenyl)-3-(2-methyl-4-(diethylamino)phenyl)phthalide

Participants

Reaction Steps

A mixture of 2-(2-methyl-4-(diethylamino)benzoyl)benzoic acid (12.48 g.), N,N,N',N'-tetraethyl-m-phenylenediamine (10.56 g.) and acetic anhydride (12 ml.) was warmed (at 40°±8° C.) during one hour, diluted with water (50 ml., then 100 ml.), adjusted to pH 4.6 and filtered. The filtrate was clarified with water and adjusted to pH 5.5. Recrystallization of the resulting product (m.p. 134°-140° C.) from methanol afforded 3-(2,4-bis(diethylamino)phenyl)-3-(2-methyl-4-(diethylamino)phenyl)phthalide (I: X=Y4 =(CH3CH2)2N, Y2 =CH3, Z4 =Z5 =Z6 =Z7 =H) (m.p. 149°-151° C.).

Provenance & Evidence