| abstract |
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.n n(wherein, R is amino or protected amino; R 1 is an ester forming group; R2 is hydrogen, cyano, or esterified carboxy; R 3 is hydrogen, cyano, or esterified carboxy: and R4 is lower alkyl or aralkyl). |