844502-63-2
2-氨基-3,4-噻吩羧酸-3-乙基-4-甲酯
→
1104926-91-1
4-oxo-3H-thieno[2,3-d]pyrimidine-5-carboxylic acid
1353498-44-8
ethyl 4-oxo-3,4-dihydrothieno[2,3-d]pyrimidine-5-carboxylate