Ionic liquid mediated synthesis, reactions, and insecticidal activity of 1-[(1H-benzoimidazol-2-yl)amino]spiro[azetidine-4,4 -[4 H ]chroman]-2-ones

Ionic liquid mediated synthesis of novel heterocyclic compounds 1-[(1H -benzoimidazol-2-yl)amino]-2 - phenylspiro[azetidine-4,4 -[4 H ]chroman]-2-ones (3) and 1-[(1H -benzoimidazol-2-yl)amino]-3-chloro-2 -phenylspiro[aze tidine-4,4 -[4 H ] chroman]-2-ones (4) was accomplished by condensing substituted 2-hydrazino benzimidazole (1), flavanone (2), and acetyl chloride/chloroacetyl chloride in ionic liquid, [bmim]PF6 with or without using catalyst in excellent yield (90%–95%). Further, compounds 3 and 4 were acylated with trifluoroacetic anhydride to give N -acylated products (5 and 10); 3 when treated with HCHO and (C2 H5)2 NH gave Mannich bases (6) and with aldehydes afforded 3-arylidene-2-azetidinone (7).