Phthalaldehyde → 2-(4-Acetylphenyl)isoindolin-1-one

Reaction equation

[C:1]([C:4]1[CH:9]=[CH:8][C:7]([N:10]=[C:11]=[O:12])=[CH:6][CH:5]=1)(=[O:3])[CH3:2].[CH:13]1[CH:18]=[C:17](C=O)[C:16]([CH:21]=O)=[CH:15][CH:14]=1.C(Cl)Cl>CO>[C:1]([C:4]1[CH:9]=[CH:8][C:7]([N:10]2[CH2:21][C:16]3[C:15](=[CH:14][CH:13]=[CH:18][CH:17]=3)[C:11]2=[O:12])=[CH:6][CH:5]=1)(=[O:3])[CH3:2]

Participants

Procedure

A mixture of 4-acetylphenylisocyanate (27.5 g, 0.17 mol) and o-phthalicdicarboxaldehyde (25.0 g, 0.186 mol) is heated in an oil bath at 170°-175° C. for 4.0 hours under nitrogen atmosphere. On cooling the melt solidified which is pulverized and refluxed with CH2Cl2 and CH3OH and filtered to give 18.2 g (41.4%) of the desired 2-(4-acetylphenyl)-2,3-dihydro-1H-isoindole-1-one, mp 235°-237° C. The residue is recrystallized from DMF (1800 ml). Yield 13.0 g (29.6%), mp 236-239° C. (Jap. patent J5 7050-960; mp 243°-244° C. for the nonsolvated compound, prepared by a different route).