Fully Continuous Flow Synthesis of 5-(Aminomethyl)-2-methylpyrimidin-4-amine: A Key Intermediate of Vitamin B1

Herein, we demonstrate an expeditiously fully continuous flow synthesis of 5-(aminomethyl)-2-methylpyrimidin-4-amine, a key intermediate for vitamin B1. The process is accomplished via three chemical transformations in six sequential continuous flow devices from an economical starting material, 2-cyanoacetamide. First, single step continuous flow synthesis is demonstrated in a certain type of flow reactor for each reaction step, with a yield of 94, 90, and 99%, respectively. Then, fully continuous flow synthesis of 5-(aminomethyl)-2-methylpyrimidin-4-amine is demonstrated in 84% total yield with a total residence time of 74 min and 0.92 g/h throughput.