An Improved and Efficient Process for the Preparation of Tofacitinib Citrate

The present invention is related to a simple and efficient process for the preparation of tofacitinib citrate 1, a Pfizer molecule approved for the treatment of rheumatoid arthritis. The process relies upon an improved process for the preparation of a key intermediate (3R,4R)-(1-benzyl-4-methylpiperidin-3-yl)methylamine as tartarate salt 3 and its simple and impurity-free conversion to tofacitinib citrate 1. The current invention is aimed at addressing process development issues related to quality and yields. The disclosed process is capable of delivering much higher yield compared to the prior state-of-the-art process and is able to yield very highly pure compound.