Synthesis of Substituted Thienopyrimidinones Based on Ethyl 2-Amino-4-(1,4-benzodioxan-2-yl)thiophene-3-carboxylate

Previously synthesized ethyl 2-benzamido-4-(1,4-benzodioxan-2-yl)thiophene-3-carboxylates were cyclized to 2-aryl-3-aminothieno[2,3- d ]pyrimidin-4(1 H )-ones by the action of hydrazine hydrate. The con­densation of ethyl 2-amino-4-(1,4-benzodioxan-2-yl)thiophene-3-carboxylate with chloroacetyl chloride gave the corresponding N-substituted 2-chloroacetamide which reacted with piperidine and morpholine to produce 2-aminoacetamides, and the latter were also subjected to cyclization with hydrazine hydrate to obtain 3-amino­thienopyrimidin-4-one derivatives. The synthesized compounds were tested for antihypoxic activity.