Two Approaches to the Chemical Development and Large-Scale Preparation of a Pyrimidyl Tetrazole Intermediate
作者:Peter Mullens、Ed Cleator、Mark McLaughlin、Brian Bishop、John Edwards、Adrian Goodyear、Teresa Andreani、Yan Jin、Jongrock Kong、Hongmei Li、Michael Williams、Michael Zacuto
DOI:10.1021/acs.oprd.6b00136
日期:2016.6.17
carboxylic acid via hydroboration and oxidation. This route was rapidly defined and used to prepare the initial 0.3 kg of the pyrimidyl tetrazole intermediate, which supported early toxicology and clinical studies of a drug candidate. A second-generation, eight-step route to the pyrimidyl tetrazole intermediate was defined and demonstrated on multikilogram scale in a 21% overall yield. The key transformation
描述了两种新的通往嘧啶基四唑中间体的途径。第一代路线的特征是在4-丁烯基溴化镁和4-氯嘧啶衍生物之间进行铁催化的交叉偶联,从而得到带有烯烃的嘧啶中间体。随后的分子内Heck环化提供了所需的双环核,其随后通过氢硼化和氧化转化为相应的羧酸。快速定义了该路线,并用于制备最初的0.3 kg嘧啶基四唑中间体,这支持了候选药物的早期毒理学和临床研究。定义了到嘧啶基四唑中间体的第二代八步路线,并以多千克规模进行了论证,总收率为21%。此序列中的关键转化是碘嘧啶的铜(I)介导的环化,以定量产率提供了靶标的双环核。由于第二代方法涉及的规模较大,因此对该路线中的许多步骤进行了重要的过程安全性评估,并介绍了这些研究的重点。