3-(3-cyclopentyloxy-4-methoxy-phenyl)-5-ethoxycarbonylmethyl-4,5-dihydro-isoxazole-5-carboxylic acid ethyl ester 、
甲胺 以
DMF (N,N-dimethyl-formamide) 为溶剂,
以50%的产率得到3-(3-cyclopentyloxy-4-methoxy-phenyl)-7-methyl-1-oxa-2,7-diazaspiro[4.4]non-2-ene-6,8-dione