2-chloro-6-fluoro-4-(2-methoxy-ethoxy)-benzylalcohol 、
(R)-4-chlorocarbonyl-3-ethyl-piperazine-1-carboxylic acid tert-butyl ester 以to give the product as a colorless oil (370 mg; 89%)的产率得到(R)-2-ethyl-piperazine-1,4-dicarboxylic acid 4-tert-butyl ester 1-(2-chloro-6-fluoro-4-(2-methoxy-ethoxy)-benzyl)ester