One-Step Synthesis of 1, 2, 3, 4-Tetrahydrobenzo[g]quinazoline-5, 10-dione Derivatives from Vitamin K₃

Abstract

The reactions of 2-halogenonaphthoquinones (5, 13, 14 and 15) and 2-methyl-1, 4-naphthoquinone (20; vitamin K₃) with primary and secondary amines were examined. 1, 3-Dialkyl-1, 2, 3, 4-tetrahydrobenzo[g]quinazoline-5, 10-diones (9) were obtained in moderate yields by treating 20 with formaldehyde in primary amines. A plausible reaction path-way is also presented.