Propargyl bromide → N,N-Dimethyl-4-(2-propynylamino)benzenesulfonamide

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Reaction Steps

Under an atmosphere of nitrogen gas, a mixture of 17 g (0.0085 mol) of 4-amino-N,N-dimethylbenzenesulfonamide, 25.5 ml (0.229 mol) of propargyl bromide, and 20.4 ml (0.175 mol) of 2,6-lutidine in 250 ml of N,N-dimethylacetamide is stirred at 90° for three and one-half hours, allowed to cool, and concentrated in vacuo. The concentrate is taken up in dichloromethane and water; the organic layer is separated, washed with brine, dried (magnesium sulfate), filtered, and concentrated in vacuo. The residue is chromatographed over 1.1 kg of silica gel with a gradient of ethyl acetate in toluene of 10 to 15% to give 12.2 g of product, Rf (10% methanol/dichloromethane)≃0.84. Recrystallization from ethanol affords 10.2 g (50%) of product, as off-white crystals; mp 128°-131° C.

Provenance & Evidence