Vol. 7, Issue 6, Part A (2021)

Abstract
3-(5-(2-oxido)-(4-substitudedphenoxy)-benzo[d][1,3,2]dioxaphosphol-5-yl)-1H-tetrazol-1-yl)thiophene-2-carboxamides(9a-g) were synthesized by condensing 3-(5-(3,4-dihydroxyphenyl)-1H-tetrazol-1-yl)thiophene-2-carboxamide (7) with 4-substituted phenyl phosphoro dichloridates (8a-g). The synthon (7) was synthesized by hydrolysis of 3-(5-(3,4-dimethoxyphenyl)-1H-tetrazol-1-yl)thiophene-2-carboxamide (6). The intermediate (6) was synthesized by condensing 3-((3,4-dimethoxy benzylidine)amino)thiophene-2-carboxamide (5) with sodium azide in Tetrahydrofuron. The synthon (5) was synthesized by reaction between 3-aminothiophene-2-caroxamide (3) and 3,4-dimethoxybenzaldehyde (4). Starting intermediate (3) was synthesized by condensation reaction between 2-cyano acetamide (1) and 1,4-dithiane-2,5-diol (2). The reagents and conditions were shown in a, b, c, d and e. The synthetic route was shown in Scheme-I.