The present invention relates to a process for preparing the hexanoic acid, 6-(nitrooxy)-, (1S,2E)-3-[(1R,2R,3S,5R)-2-[(2Z)-7-(ethylamino)-7-oxo-2-hepten-1-yl]- 3,5-dihydroxycyclopentyl]-1-(2-phenylethyl)-2-propen-1-yl ester of formula (I). In accordance with the present invention, the compound (I) can be efficiently prepared with high purity by coupling bimatoprost in a boronate protected form with 6-(nitrooxy)hexanoyl chloride and removing the boronate protecting group. The 6-(nitrooxy)hexanoyl chloride intermediate is prepared by ring-opening reaction of 2-caprolactone and subsequent nitration of the 6-hydroxyhexanoic acid potassium salt with a mixture of HNO3 and H2SO4 in dichloromethane.
本发明涉及一种制备式(I)的
己酸6-(硝基氧)-,(1S,2E)-3-[(1R,2R,3S,5R)-2-[(2Z)-7-(乙基
氨基)-7-氧代-
2-庚烯-1-基]-3,5-二羟基环戊基]-1-(2-苯乙基)-2-
丙烯-1-基酯的方法。根据本发明,化合物(I)可以通过将
硼酸保护的
比马前列素与6-(硝基氧)
己酰氯偶联并去除
硼酸保护基来高效纯净地制备。6-(硝基氧)
己酰氯中间体通过2-
己内酯的开环反应和随后在
二氯甲烷中使用
HNO3和H2SO4混合物对
6-羟基己酸钾盐进行硝化制备。