Acetic Anhydride → 1(3H)-Isobenzofuranone, 3-[2,4-bis(dimethylamino)phenyl]-3-[4-(diethylamino)-2-methylphenyl]-

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-(2-methyl-4-(diethylamino)benzoyl)-benzoic acid (25 g.), N,N,N',N'-tetramethyl-m-phenylenediamine (13.2 g.) and acetic anhydride (75 g.) was heated (to 95° C.) during 1 hour, then refluxed with dilute hydrochloric acid (32 g. concentrated hydrochloric acid plus 160 ml. water) during one and one-half hours. The resulting mixture was poured onto ice and the pH was adjusted to 6 with sodium hydroxide. Recrystallization of the resulting product afforded 3-(2,4-bis(dimethylamino)-phenyl)-3-(2-methyl-4-(diethylamino)phenyl)phthalide (I: X = (CH3)2N, Y2 = CH3, Y4 = (CH3CH2)2N, Z4 = Z5 = Z6 = Z7 = H) in a first crop from toluene (m.p. 204°-206° C.) and in a second crop from a mixture of toluene and hexane (m.p. 191°-195° C.).

Provenance & Evidence