A practical and scalable process is described for the preparation of 2-(methansulfonyl) benzenesulfonyl chloride, a key building block used in the synthesis of several drug candidates. The material is prepared by an efficient four-step sequence from inexpensive 1, 2-dichlorobenzene and methanethiol, and the process has been demonstrated on a multikilogram scale in 32% overall yield with a chemical purity of> 98%.
