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
氧基)-、(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-
苯基乙基)-2-
丙烯-1-基
酯的工艺。
根据本发明,通过将
硼酸酯保护形式的
比马前列素与 6-(硝基
氧基)
己酰氯偶联,并去除
硼酸酯保护基团,可高效制备出高纯度的化合物 (I)。
6-(硝基
氧基)
己酰氯中间体是通过 2-
己内酯的开环反应以及随后在
二氯甲烷中用
HNO3 和 H2SO4 的混合物硝化
6-羟基己酸钾盐制备的。