4-Toluenesulfonyl chloride → p-Toluenesulfonyl azide

Participants

Reaction Steps

Tosyl azide was prepared as follows. A solution of sodium azide (58.5 g, 0.90 tool) in distilled water (170 mL) was quickly added to a stirred suspension (partly in solution) of p-toluenesulfonyl chloride (143.0 g, 0.75 tool) in isopropanol (850 mL) contained in a beaker at room temperature. The mixture was stirred for one hour, then poured into 3 L of distilled water and stirred for one more hour. The separated oily tosyl azide was washed three times with water, dried over anhydrous magnesium sulfate, then dried by stirring under vacuum. It is important for its use as a reagent in the lithiation reaction that tosyl azide is substantially pure (free of impurities) and contains a negligible amount of water (measured by proton NMR). 114 g of colourless tosyl azide oil was obtained (yield 77%). A 95% yield could be obtained by extracting the drying agent with chloroform. 1HNMR: δ=7.84 H-ortho-sulfonyl (2H d, J≈8.3); δ=7.41 H-orthomethyl (2H d, J≈8.3); δ=2.49 Me (3H s).

Provenance & Evidence