Chloroacetone → 2-(2-Oxopropyl)-1H-1lambda~6~-naphtho[2,1-d][1,2]thiazole-1,1,3(2H)-trione

Participants

Reaction Steps

46.6 gm (0.2 mol) of 3-oxo-naphth[2,1-d]isothiazoline -1,1-dioxide were added to a solution of 5.3 gm (0.23 gm-atom) of sodium in 150 ml of methanol and the majority of the alcohol was distilled off. The residue was taken up in 50 ml of dry dimethyl sulfoxide. 23.2 gm (20 ml; 0.25 mol)of chloroacetone were added dropwise over a period of 10 minutes, and the resulting mixture was stirred at room temperature for 30 minutes and was then heated at 120° C for 2.5 hours. The dimethyl sulfoxide was then partly distilled off in vacuo, a solution of 25 gm of sodium acetate in 250 ml of water was added to the residue, accompanied by exterior cooling, and the resulting mixture was thoroughly stirred. The precipitatewhich had formed was suction-filtered off and washed first with water and then with a small quantity of ice-cold ethanol. The crude product (52.3 gm; 90% of theory) thus obtained, m.p. 163°-165° C, may be used as such in the next reaction step. Pure 2-acetonyl-3-oxo-naphth[2,1-d]isothiazoline-1,1-dioxide, recrystallized from ethanol, melted at 164°-165° C.

Provenance & Evidence