The Development of a Robust Process for a CRF1 Receptor Antagonist
摘要:
A scalable and robust process was developed for the preparation of pexacerfont (2), a pyrazolotriazine corticotropin-releasing factor receptor 1 antagonist (CRF1). The formation of the core hydroxypyrazolotriazine moiety was achieved through two consecutive cyclizations of a semicarbazide, employing reaction conditions that are significantly milder than those reported in the literature. Further conversion to the key chloropyrazolotriazine intermediate was accomplished through a novel catalytic process using phosphorous oxychloride as the chlorinating agent. The active pharmaceutical ingredient 2 was obtained in > 99.5% purity with a 68% overall yield for the six synthetic steps.
interpretation of 1D and 2D (HMQC, HMBC) NMR data where (1)H-(15)N HMBC correlations revealed the position of carbamoyl group attachment on the pyrazole. Comparison of structures of the target-compound and the by-product showed that the latter resulted from N-N migration of the carbamoyl group in the target-compound.
The Development of a Robust Process for a CRF<sub>1</sub> Receptor Antagonist
作者:Sévrine Broxer、Monica A. Fitzgerald、Chris Sfouggatakis、Jessica L. Defreese、Evan Barlow、Gerald L. Powers、Michael Peddicord、Bao-Ning Su、Yue Tai-Yuen、Charles Pathirana、James P. Sherbine
DOI:10.1021/op100270u
日期:2011.3.18
A scalable and robust process was developed for the preparation of pexacerfont (2), a pyrazolotriazine corticotropin-releasing factor receptor 1 antagonist (CRF1). The formation of the core hydroxypyrazolotriazine moiety was achieved through two consecutive cyclizations of a semicarbazide, employing reaction conditions that are significantly milder than those reported in the literature. Further conversion to the key chloropyrazolotriazine intermediate was accomplished through a novel catalytic process using phosphorous oxychloride as the chlorinating agent. The active pharmaceutical ingredient 2 was obtained in > 99.5% purity with a 68% overall yield for the six synthetic steps.