(1R,3aS,3bS,10aR,10bS,11S,12aS)-7-(4-fluorophenyl)-1,11-dihydroxy-10a,12a-dimethyl-1,2,3,3a,3b,4,5,7,10,10a,10b,11,12,12a-tetradecahydrocyclopenta[5,6]naphtho[1,2-f]indazole-1-carbothioic S-acid 、
氯甲酸乙酯 在
三乙胺 、
N,N-二甲基-N'-乙基乙二胺 作用下,
以
二氯甲烷 为溶剂,
反应 0.5h,
以90%的产率得到(1S,2R,13S,14S,17R,18S,20S)-17-ethoxycarbonyloxy-7-(4-fluorophenyl)-20-hydroxy-2,18-dimethyl-6,7-diazapentacyclo[11.7.0.02,10.04,8.014,18]icosa-4(8),5,9-triene-17-carbothioic S-acid