ethyl 4-oxo-3,4-dihydroquinazoline-2-carboxylateEthyl 4-quinazolone-2-carboxylate4-喹唑啉酮-2-甲酸乙酯Ethyl 4-oxo-3,4-dihydro-2-quinazolinecarboxylateEthyl 3,4-dihydro-4-oxoquinazoline-2-carboxylate3,4-Dihydro-2-(ethoxycarbonyl)-4-oxoquinazolineEthyl 1,4-dihydro-4-oxoquinazoline-2-carboxylate4-Quinazolone-2-carboxylic acid ethyl ester