Reactions of 3-Benzoyl-3, 4-dihydro-2-methyl-4-quinazolinecarbonitrile(2-Methylquinazoline Reissert Compound) with Acid, Base, Sodium Hydride, and Electrophiles

Abstract

Acid hydrolysis of 3-benzoyl-3, 4-dihydro-2-methyl-4-quinazolinecarbonitrile (1₁, 2-methyl-quinazoline Reissert compound) resulted in the formation of the oxazole (1₃). Alkaline hydrolysis gave 2-methylquinazoline (1₂) and benzoic aicd (8). The anion (D¹), generated from 1₁ and NaH in dimethylformamide (DMF), underwent decomposition to give the ketone (1₄) and the cyanoquinazoline (1₅) together with by-products 1₂ and O-benzoylbenzoin (9). Compound 1₁ reacted with aromatic aldehydes (10a-c) in the presence of NaH to give the benzoates (1₆a-c) and by-products 1₂ and 1₅. Alkylation (or arylation) with alkyl (or aryl) halides (11a, b) afforded the corresponding 4-substituted derivatives (1₉a, b) and a by-product 1₄.The reactivities of 1₁. and 3-benzoyl-3, 4-dihydro-4-quinazolinecarbonitrile (2₁, quinazoline Reissert compound) are compared.