1,1-dioxo-2-(2-oxopropyl)-1,2-benzothiazol-3-one

Conditions: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The N-acetonylsaccharin of Section B of this Example was treated with sodium methoxide in accordance with Zinnes et al, J. Org. Chem., 30:2241 (1965), U.S. Pat. No. 3,284,450, and Rasmussen, J. Org. Chem., 39:1554 (1974). Laboratory reagent sodium methoxide (0.9 mole) was blended with 50 ml of absolute ethanol and heated to 40° C.; 0.04 mole of the N-acetonylsaccharin was then added and the resulting mixture heated with stirring to 60° C. The mixture was then cooled and acidified with 5% HCl, resulting in the formation of a precipitate. The precipitate was washed, dried, filtered and evaporated to give an oily solid in 68% yield. the resulting mixture heated The mixture was then cooled resulting in the formation of a precipitate The precipitate was washed dried filtered evaporated to give an oily solid in 68% yield

Conditions: temp:34.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 7.4 g (42 millimoles) of diethylcyanomethyl phosphonate and 6.8 g (38 millimoles) of 30% strength sodium methylate were simultaneously added dropwise to 10.0 g (42 millimoles) of N-acetonylsaccharin in 200 ml of dimethylformamide, while stirring thoroughly, the temperature increasing to 34° C. The reaction mixture was stirred for a further hour at room temperature, after which the contents of the flask were poured onto ice-water and extracted three times with methylene chloride, the organic phase was dried and evaporated down under reduced pressure, and the crude product was recrystallized from ethanol to give 2.5 g (23%) of 3-(2,3-dihydro-1,1-dioxido-3-oxo-1,2-benzisothiazol-2-yl)-1-cyano-2-methylprop-1-ene of melting point 118°-121° C. The reaction mixture was stirred for a further hour at room temperature after which the contents of the flask were poured onto ice-water extracted three times with methylene chloride the organic phase was dried evaporated down under reduced pressure the crude product was recrystallized from ethanol

Conditions: temp:110.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 26 ml (324 millimoles) of chloroacetone were slowly added dropwise to 40.0 g (200 millimoles) of sodium saccharin, while stirring (exothermic reaction). The temperature was gradually increased to 110° C., and the reaction mixture was stirred at this temperature for 5 hours, after which it was cooled. An excess of ice-water was added, and stirring was continued for a further hour. The precipitated solid was filtered off under suction, recrystallized from ethanol and dried in a drying oven under reduced pressure at 50° C. to give 35.2 g (74%) of N-acetonylsaccharin of melting point 142°-143° C. (exothermic reaction) the reaction mixture was stirred at this temperature for 5 hours after which it was cooled stirring was continued for a further hour The precipitated solid was filtered off under suction recrystallized from ethanol dried in a drying oven under reduced pressure at 50° C.

Conditions: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The N-acetonylsaccharin of Section B of this Example was treated with sodium methoxide in accordance with Zinnes et al, J. Org. Chem., 30:2241 (1965), U.S. Pat. No. 3,284,450, and Rasmussen, J. Org. Chem., 39:1554 (1974). Laboratory reagent sodium methoxide (0.9 mole) was blended with 50 ml of absolute ethanol and heated to 40° C.; 0.04 mole of the N-acetonylsaccharin was then added and the resulting mixture heated with stirring to 60° C. The mixture was then cooled and acidified with 5% HCl, resulting in the formation of a precipitate. The precipitate was washed, dried, filtered and evaporated to give an oily solid in 68% yield. the resulting mixture heated The mixture was then cooled resulting in the formation of a precipitate The precipitate was washed dried filtered evaporated to give an oily solid in 68% yield