A Greener Approach for the Large-Scale Synthesis of 1,4,5-Trisubstituted Pyrazole, AZD8329

The development of a convenient, safe and scalable process for AZD8329 manufacturing is reported here. Synthesis was achieved in a two-step telescopic process with an excellent overall yield of 75%. In the first step enamine (6) was synthesized with 90% yield through three chemical transformations. In the next step AZD8329 was synthesized from the reactions of 6 and 4-hydrazinobenzoic acid hydrochloride 7 through two chemical transformations. The process is very efficient and economical, and AZD8329 was manufactured in multikilogram scale. A greener approach is demonstrated through usage of a minimum number of solvents and energy and with process mass intensity (PMI)