Hydrochloric Acid → 5-(4-Chloro-3-chlorosulfonylphenyl)-5-hydroxy-1-methyl-2-pyrrolidone

Participants

Reaction Steps

A solution of 9.9 g of sodium nitrite in 60 ml of water is metered into, below the surface of, a solution of 30.5 g of 5-(3-amino-4-chlorophenyl)-5-hydroxy-1-methyl-2-pyrrolidone in 300 ml of half-concentrated hydrochloric acid at at 0° to 5° C. The reaction mixture is stirred while cooling for a further 10 min, and then a mixture of 15.2 g of copper(II)chloride dihydrate and 450 ml of a saturated solution of sulfur dioxide in glacial acetic acid is added in portions. The mixture is stirred for a further 30 min, and then the sulfonyl chloride is precipitated by addition of water, and the crystals are filtered off. Melting point 137°-139° C.

Provenance & Evidence