Dimethylformamide → 2-Chloro-5-nitrobenzenesulfonamide

Participants

Reaction Steps

To a solution of thionyl chloride (11 mL) and 2-chloro-5-nitro-benzenesulfonic acid (4.78 g, 20.1 mmol) was added N,N-dimethylformamide (0.92 μL) and the reaction mixture was heated to reflux for 4 h. Upon cooling, the reaction mixture was azeotroped with toluene (2-3×). The sulfonyl chloride was dissolved in a minimal amount of toluene and then added to a mixture of concentrated aqueous ammonium hydroxide solution (25 mL) and tetrahydrofuran (25 mL) at −10° C. After stirring for 2 h the reaction was quenched by adding a 6.0 M aqueous hydrochloric acid solution until pH 4 was reached. The layers were separated and the organic layer was concentrated in vacuo to a slurry. Pentane was added and the product was isolated by vacuum filtration to afford the desired product, 2-chloro-5-nitrobenzenesulfonamide (2.0 g, 8.48 mmol, 42.4%) as a solid.

Provenance & Evidence