The present invention relates to 11β-fluoro-3-acetoxyestra-3,5-dien-17-one as a suitable intermediate in the preparation of 11-fluoro-substituted steroids and to the process for preparation thereof. For this purpose, 11α-hydroxyestra-4-ene-3,17-dione is reacted with 1 to 3 equivalents of n-nonafluorobutanesulfonyl fluoride and 3 to 5 equivalents of diazabicycloundecene (DBU) at −40 to −20° C. in an organic aprotic solvent and, after an aqueous workup, reacted with 5 to 10 equivalents of acetic anhydride and 0.01 to 1 equivalent of a strong acid. The desired product precipitates spontaneously out of the reaction solution and is obtained in a very high purity by filtration. The process is notable for the very high yield, avoidance of a chromatographic purification of the product, a reduced proportion of wastes and significantly increased process throughput. The process according to the invention is therefore especially suitable for preparing 11β-fluoro-3-acetoxyestra-3,5-dien-17-one on a large industrial scale.
本发明涉及11β-
氟-3-乙酰氧基雌-3,5-二烯-17-酮作为制备11-
氟取代类
固醇的适宜中间体以及其制备过程。为此,在有机无
水溶剂中,将11α-羟基雌-4-烯-3,17-二酮与1至3当量的N-非八
氟丁烷磺酰
氟和3至5当量的二氮杂双
环十一烷(
DBU)在-40至-20℃反应,然后进行
水工艺处理,再与5至10当量的
乙酸酐和0.01至1当量的强酸反应。所需产品会自发地从反应溶液中沉淀出来,并通过过滤得到高纯度的产物。该过程以高收率、避免产物的色谱纯化、减少废物比例和显著提高的工艺吞吐量而著称。因此,本发明的工艺特别适用于在大型工业规模下制备11β-
氟-3-乙酰氧基雌-3,5-二烯-17-酮。