2-chloro-4-fluoro-5-isocyanato-benzoic acid-1-methylethylester 、
3-氨基巴豆酸乙酯 以there is obtained isopropyl 2-chloro-4-fluoro-5-{3-[2-(ethoxycarbonyl)-1-methylvinyl]ureido}benzoate, m.p. 147°-150° C.的产率得到isopropyl 2-chloro-4-fluoro-5-{3-[2-(ethoxycarbonyl)-1-methyl-vinyl]ureido}-benzoate