Nitrogen heterocycles. Part 7. Some reactions of 2-anilinophthalimidine derivatives

Abstract

2-Anilino-3-benzyl-3-hydroxyphthalimidine (1) gives, on treatment with acids under various conditions, the methoxy-derivative (2), 2-anilino-3-benzylidenephthalimidine (3), 2-(o-carbamoylphenyl)-3-phenylindole (7), and 11-phenylisoindolo[2,1-a]indol-6-one (8). Compound (8) may be obtained also by pyrolytic rearrangement of (3). Pyrolysis of (1) affords 4-benzyl-3-phenylphthalizinium-3-olate (11), which can be transformed into a number of compounds, including the cycloadduct (12) with dimethyl but-2-ynedioate. Bromination of (3) gives 2-(p-bromoanilino)-3-benzylidenephthalimidine (5) and 3-bromo-2-(p-bromoanilino)-3-(α-bromobenzyl)-phthalimidine (16), which, by reaction with methanol or ethanol, affords the alkoxy-derivative [(17) or (18)]. Compounds (1) or (3), (5), (17), and (18) are converted by bases into the corresponding phthalazinones (19)–(22).