Reaction #55293

Reaction equation

hydrochloric acid

2-(2-ethoxy-4-(diethylamino)benzoyl)benzoic acid

N,N,N',N'-tetramethyl-m-phenylenediamine

acetic anhydride

→

3-(2,4-bis(dimethylamino)phenyl)-3-(2-ethoxy-4-(diethylamino)phenyl)phthalide

Conditions

Workup

1. 1
   Temperaturewas heated (70°-75° C.) during one hour
2. 2
   OtherRecrystallization of the resulting red precipitate from hexane

Procedure

A mixture of 2-(2-ethoxy-4-(diethylamino)benzoyl)benzoic acid (6.82 g.), N,N,N',N'-tetramethyl-m-phenylenediamine (2.80 g.) and acetic anhydride (20 g.) was heated (70°-75° C.) during one hour, let stand overnight and poured into dilute hydrochloric acid. The resulting mixture was basified. Recrystallization of the resulting red precipitate from hexane followed by slurrying in alkaline water afforded 3-(2,4-bis(dimethylamino)phenyl)-3-(2-ethoxy-4-(diethylamino)phenyl)phthalide (I: X=(CH3)2N, Y2 =CH3CH2O, Y4 =(CH3CH2)2N, Z4 =Z5 =Z6 =Z7 =H) (m.p. 146°-150° C.).

Source