Development of a Large Scale Asymmetric Synthesis of the Glucocorticoid Agonist BI 653048 BS H<sub>3</sub>PO<sub>4</sub>
作者:Jonathan T. Reeves、Daniel R. Fandrick、Zhulin Tan、Jinhua J. Song、Sonia Rodriguez、Bo Qu、Soojin Kim、Oliver Niemeier、Zhibin Li、Denis Byrne、Scot Campbell、Ashish Chitroda、Phil DeCroos、Thomas Fachinger、Victor Fuchs、Nina C. Gonnella、Nelu Grinberg、Nizar Haddad、Burkhard Jäger、Heewon Lee、Jon C. Lorenz、Shengli Ma、Bikshandarkoil A. Narayanan、Larry J. Nummy、Ajith Premasiri、Frank Roschangar、Max Sarvestani、Sherry Shen、Earl Spinelli、Xiufeng Sun、Richard J. Varsolona、Nathan Yee、Michael Brenner、Chris H. Senanayake
DOI:10.1021/jo400079z
日期:2013.4.19
The development of a large scale synthesis of the glucocorticoid agonist BI 653048 BS H3PO4 (1·H3PO4) is presented. A key trifluoromethyl ketone intermediate 22 containing an N-(4-methoxyphenyl)ethyl amide was prepared by an enolization/bromine–magnesium exchange/electrophile trapping reaction. A nonselective propargylation of trifluoromethyl ketone 22 gave the desired diastereomer in 32% yield and
提出了糖皮质激素激动剂BI 653048 BS H 3 PO 4(1·H 3 PO 4)大规模合成的进展。通过烯醇化/溴-镁交换/亲电子俘获反应制备了含有N-(4-甲氧基苯基)乙基酰胺的关键三氟甲基酮中间体22。三氟甲基酮的非选择性炔丙基化22结晶后得到的非对映异构体,收率为32%,dr = 98:2,由1:1非对映异构体混合物提供。随后,进行了不对称的炔丙基化,其在结晶后以4:1的非对映选择性和75%的产率提供了所需的非对映异构体,dr = 99:1。通过一锅交叉偶联/吲哚化反应有效地安装了氮杂吲哚部分。使用H 3 PO 4 /茴香醚开发了对4-甲氧基苯乙基的有效脱保护基,以高收率和高纯度生产API的茴香醚溶剂化物。最终形式,磷酸共晶,以高收率和纯度生产,并具有一致的粒度控制。