2-oxocyclohexane-1-sulfonamide

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

Procedure: A solution of 16.7 g (0.1 mol) of morpholinocyclohexene in 200 ml of tetrahydrofuran was treated simultaneously, over a period of 2 hours, at -50° C., with solutions of 12.7 g (0.11 mol) of sulfamoyl chloride and 11.1 g (0.11 mol) of triethylamine each in 100 ml of tetrahydrofuran, the mixture was brought from -50° to 20° C. over a period of 2 hours and filtered, the filtrate was evaporated to dryness in vacuo and the residue was chromatographed on 400 g of silica gel with methylene chloride. After recrystallization from isopropanol, the main fraction yielded 9.7 g (54.8% of theory, based on enamine) of 2-oxocyclohexanesulfonamide of melting point 118°-119° C. filtered the filtrate was evaporated to dryness in vacuo the residue was chromatographed on 400 g of silica gel with methylene chloride After recrystallization from isopropanol the main fraction yielded 9.7 g (54.8% of theory, based on enamine) of 2-oxocyclohexanesulfonamide of melting point 118°-119° C.

Conditions: temp:-60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Thereafter, the mixture was cooled to −60° C. and sulfamoyl chloride (11.85 g) in anhydrous THF (100 ml) was added dropwise (temperature increase from −60° C. to about −40° C.). The mixture was then cooled to −60° C. Then a solution of Hünig's base (13.3 g) in anhydrous THF (50 ml) was added gradually. The mixture was warmed up to room temperature and stirred for 2 hours. An unstirrable oil was the result. The THF was decanted off, and the oily residue was dissolved in methanol and filtered through silica gel. Subsequently, the methanol was removed under reduced pressure. The residue was dissolved completely in boiling 1:1 ethyl acetate/n-heptane (40 ml). After cooling to room temperature, the solution was cooled to 5° C. in a refrigerator. The precipitate was subsequently filtered off with suction using a frit. This gave the product (5.3 g) with a molecular weight of 177.2 g/mol (C6H11NO3S), MS (EST): m/e=178 (M+H+). (temperature increase from −60° C. to about −40° C.) The mixture was then cooled to −60° C The mixture was warmed up to room temperature The THF was decanted off the oily residue was dissolved in methanol filtered through silica gel Subsequently, the methanol was removed under reduced pressure The residue was dissolved completely After cooling to room temperature the solution was cooled to 5° C. in a refrigerator The precipitate was subsequently filtered off with suction