Synthesis of Substituted Thienopyrimidinones Based on 2-Amino-4-(1,4-benzodioxan-2-yl) Thiophene-3-carboxylic Acid Ethyl Ester

The previously obtained N-arylamides of 2-amino-4-(1,4-benzodioxan-2-yl)thiophene-3-carboxylic acid ethyl ester were cyclized to 2-aryl-substituted 3-aminothienopyrimidin-4-ones by the action of hydrazine hydrate. By condensation of the starting amino ester with chloroacetic acid chloride was obtained chloramide, which was converted by the action of piperidine and morpholine into the corresponding aminomethylamides. The latters were also subjected to cyclization with hydrazine hydrate to 3-aminothienopyrimidin-4-one derivatives with aminomethyl substituents in the second position. The antihypoxic activity of the synthesized compounds was studied.