Regioselective Synthesis of Some Novel Phosphonopyrazole, Phosphonopyrimidine and Phosphonodiazepine Compounds Containing Coumarin Ring

Abstract

A convenient regioselective synthesis of some novel phosphonopyrazole, phosphonopyrimidine and phosphonodiazepine derivatives containing a coumarin ring, was designed. The methodology involves one-pot reaction of 3-(2-bromoacetyl)-2H-chromen-2-one (1) with dimethylformamide dimethyl acetal and diethyl phosphite to give diethyl [2-bromo-3-oxo-3-(2-oxo-2H-chromen-3yl)prop-1-en-1-yl]phosphonate (2). The successful heterocyclization of substrate 2 with 1,2-, 1,3-and 1,4-diamine reagents afforded the target products in moderate to good yields.