Sulfuric Acid → 5-(Benzenesulfinyl)-2-nitroaniline

Participants

Reaction Steps

10 G. of 1-amino-5-phenylthio-2-nitrobenzene in 100 ml. of acetic anhydride is treated with 0.25 ml. of concentrated sulfuric acid. The mixture is kept at 20°-25° C for 2 hours, then neutralized with sodium acetate and the solvent removed under vacuum. The residue is washed with water and methanol and dried. The resulting 1-acetamido-5-phenylthio-2-nitrobenzene is dissolved in 100 ml. of chloroform and treated at -30° C with a solution of peracetic acid (1 equivalent) in 10 ml. of methanol. The solution is warmed slowly to 20°-25° C and kept at the temperature for 12 hours, then washed successively with a solution of sodium bisulfite and a solution of sodium carbonate. Removal of the solvent leaves a gum which is treated with a mixture of 30 ml. of 5 N. sodium hydroxide and 60 ml. of methanol at 20°-25° C for 1 hour. Dilution with water followed by filtration of the product gives 1-amino-5-phenylsulfinyl-2-nitrobenzene which is purified by recrystallization from cyclohexane.

Provenance & Evidence