Preparation of 1-(4-nitrophenyl methanesulfonyl) pyrrolidine

1-(4-Nitrophenyl methanesulfonyl) pyrrolidine (V) was prepared by four-step reactions, starting from benzyl chloride (I). p-Nitro benzyl chloride (II) was prepared by the nitration of I with fuming nitric acid-fuming sulfuric acid, with a yield of 52%. Sodium p-nitro benzyl sulfonate (III) was prepared by the sulfonation of II with Na₂SO₃, with a yield of 96%. p-Nitrophenyl methanesulfonyl chloride (IV), was obtained by chlorination of III with PCl₅, with a yield of 78%. Aminolysis of IV with pyrrolidine gave the title compound V, with a yield of 98%. The procedure was improved and total yield was increased.