Hydrochloric Acid → 3-Acetyl-4-hydroxy-1lambda~6~-naphtho[2,1-e][1,2]thiazine-1,1(2H)-dione

Participants

Reaction Steps

28.9 gm (1.0 mol) of 2-acetonyl-3-oxo-naphth[2,1-d]isothiazoline-1,1-dioxide were added to a solution of 4.7 gm (2.04 gm-atom) of sodium in 125 ml of ethanol at 30° C. The resulting mixture was kept at 55° C for 2 hours, while stirring, and was subsequently refluxed for 15 minutes. After cooling, the reaction mixture was acidified with 350 ml of aqueous 9% hydrochloric acid, and the solid product formed thereby was suction-filtered off and washed with ice-cold 50% ethanol. Recrystallization from ethanol yielded 15.6 gm (54% of theory) of 3-acetyl-4-hydroxy-2H-naphtho[2,1-e]-1,2-thiazine-1,1-dioxide, m.p. 191°-192° C.

Provenance & Evidence