A useful intermediate, glutaconic acid ester derivative (III), is prepared by Michael-type condensation of thiazoleacetic acid derivative (1) with alkoxyacrylic acid derivative (II) in the presence of base.
(wherein, R is amino or protected amino; R1 is an ester forming group; R2 is hydrogen, cyano, or esterified carboxy; R3 is hydrogen, cyano, or esterified carboxy: and R4 is lower alkyl or aralkyl).
噻唑乙酸衍
生物(1)与烷氧基
丙烯酸衍
生物(II)在碱存在下进行迈克尔式缩合,可制备出有用的中间体--
戊二酸酯衍
生物(III)。
(其中,R 是
氨基或保护
氨基;R1 是形成酯的基团;R2 是氢、
氰基或酯化羧基;R3 是氢、
氰基或酯化羧基;R4 是低级烷基或芳烷基)。