As we know Anti-cancer Drug have very tight and stringent specifications in final stage purity then only US FDA use to allow to keep that particular drug in to the market, especially in the preparation of Letrozole Drug one of the key Fluoro intermediate is 4-fluorobenzonitrile which is already available in market, using same difficult to generate desired specification at final stage of Letrozole Drug. So that, to avoid these issues we have worked on synthesizing this intermediate in our unit. In literature there are so many synthetic procedures are available but they are not industrial approach procedures almost all routes are involved costly key starting materials but in our research the starting material is 4-Fluorobenzaldehyde other key reagent is Hydroxylamine hydrochloride and solvents Dimethyl Suloxide (DMSO) and water.