The invention relates to a process for the preparation of synthetic pyrethroid insecticides. The process involves coupling of carboxylic acid (IV) with an alcohol (V) in the presence of a catalyst wherein R1, R2, R3 and Ar are defined in the specification.本發明係關於一種製備合成擬除蟲菊酯殺蟲劑的方法。該方法包括羧酸(IV)與醇(V)在催化劑存在下的偶合,其中R1、R2、R3和Ar係在說明書中定義。