1
The present invention provides a process for preparing a compound of formula (I), wherein R represents C
1
-C
4
alkyl; and X represents an alkyl, alkenyl, cycloalkyl, aryl, substituted aryl, heterocycle, or substituted heterocycle, comprising treating a compound of formula (II), with a suitable crown ether and a suitable base followed by addition of a compound of formula R
−
M
+
wherein M
+
is a suitable cation.
本发明提供了一种制备式(I)化合物的方法,其中R代表C1-C4烷基;X代表烷基,烯基,环烷基,芳基,取代芳基,杂环或取代杂环,包括用适当的
冠醚和适当的碱处理式(II)化合物,随后加入式R-M+的化合物,其中M+是适当的阳离子。