Study on Preparation Process of Anticoagulant BAY2433334

A new process route suitable for the industrial production of BAY2433334 has been developed in this paper, which avoids the patent limitations of the originator company of BAY2433334 to the preparation of BAY2433334. BAY2433334 is obtained from (2<i>R</i>)-2-aminobutyric acid by esterification, diazotization, condensation reactions, deacetyl deprotection, activation reactions, and Mitsunobu reactions. This method is simple to operate, and the raw materials are inexpensive and readily available. Simultaneously, the product quality is very high; few O-alkylated impurities are generated during the reaction, with a high N-alkylated product/O-alkylated product ratio (above 35-45:1). As a result, the ee value is greater than 99%, which means that there are very few isomers present such that no chiral resolution is required, which greatly reduces the cost.