The present invention relates to a process for the preparation of compounds of formula (4) wherein a carbonyl compound of the formula (3) is reacted in the presence of a cyanogenation agent with an enol ester of the formula (1) or with an oxime ester of the formula (2):
wherein R1 through R8 have meanings given in the application.
The compound of formula (4) can be hydrolysed to obtain the corresponding compound of formula (5):
本发明涉及一种制备式 (4) 化合物的工艺,其中式 (3) 的羰基化合物在
氰化剂存在下与式 (1) 的烯醇酯或式 (2) 的
肟酯反应:
其中 R1 至 R8 的含义见本申请。
式(4)化合物经
水解后可得到相应的式(5)化合物: