Methyl vinyl ketone → N-benzyl-2-nitro-N-(3-oxobutyl)benzenesulfonamide

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Reaction Steps

To a solution of benzylamine (1 ml, 9.16 mmol) in ethyl acetate (10 ml) was added triethylamine (1.252 ml, 9.16 mmol) followed 2-nitrobenzene-1-sulfonyl chloride (2.03 g, 9.16 mmol) at 5-10° C. with stirring. The mixture was stirred for 1 hour (complete by HPLC), stirring continued for 1 hour. The reaction mixture was quenched with water. The organic layer was separated, washed with brine, dried, and concentrated under reduced pressure. The residue was dissolved in ethyl acetate (8 ml) and to the resulting solution potassium tert-butoxide (0.051 g, 0.458 mmol) was added followed by methyl vinyl ketone (0.755 ml, 9.16 mmol) with stirring in one portion at 20-25° C. The mixture was stirred for 2 hours at 20-25° C., quenched with brine. The organic phase was separated and the aqueous layer was back extracted with ethyl acetate (5 mL). The combined organic layers were washed with 0.6N HCl (10 mL), concentrated to 3 volumes. The solution was diluted with isopropanol (20 mL), concentrated under reduced pressure until a precipitate appeared. The resulting slurry was then stirred at 20° C. for 4 hours, filtered. The collected solid was then washed with 2-propanol (2×40 mL), dried to give N-benzyl-2-nitro-N-(3-oxobutyl)benzenesulfonamide (2.5 g, 6.87 mmol, 75% yield).

Provenance & Evidence