A convenient synthesis and biological evaluation of some novel linear and cyclic α-aminophosphonic acid derivatives containing a quinazolinone ring

Abstract

Synthesis of some novel linear and cyclic α-aminophosphonic acids and their esters bearing a quinazolin-4(3H)-one ring was achieved. The methodology depends on Pudovik reaction conditions in which using 3-(benzylideneamino)-2-phenyl-quinazolin-4(3H)-one (2) with phosphorous acid, diethyl phosphite and tris(2-chloroethyl) phosphite gives the corresponding linear α-aminophosphonic acid derivatives 3, 5 and 7, respectively, in good yields. Heterocyclization of the linear compounds to 1,4,2-oxazaphosphinanes as cyclic α-aminophosphonic acid derivatives 4, 6 and 8, respectively, was carried out. The synthesized compounds were evaluated for their antimicrobial and antioxidant activities. The cyclic α-aminophosphonic acids and their esters showed better antimicrobial and antioxidant activities than the corresponding linear α-aminophosphonic acids and their esters. Synthesis of some novel linear and cyclic α-aminophosphonic acids and their esters bearing a quinazolin-4(3H)-one ring as antimicrobial and antioxidant agents from 3-(benzylideneamino)-2-phenyl-quinazolin-4(3H)-one was achieved.