Triethylamine → N-benzyl-N-(3-hydroxy-4,4-dimethoxybutyl)-2-nitrobenzenesulfonamide

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Reaction Steps

To a solution of (E)-4-(benzylamino)-1,1-dimethoxybut-3-en-2-one (1.176 g, 5 mmol) in a mixture of 2-Propanol (12.5 ml) and Water (1.200 ml) was added sodium borohydride (0.757 g, 20.00 mmol) in portions, the mixture was stirred for 7 hours. Quenched with 5N HCl to pH 7 (approx 2.5 ml), pH adjusted to 8-9 with 5N NaOH, diluted with MTBE (25 ml) and brine (15 ml). Organic phase was separated, triethylamine (0.767 ml, 5.50 mmol) was added with ice-cooling followed by 2-nitrobenzene-1-sulfonyl chloride (1.108 g, 5.00 mmol). The mixture was left at 0-5° C. (fridge) overnight. Washed with water, dried, evaporated to dryness, the residue applied on a column, eluted with petroleum ether-ethyl acetate mixture 1:1, fractions collected to give N-benzyl-N-(3-hydroxy-4,4-dimethoxybutyl)-2-nitrobenzenesulfonamide (1.9 g, 4.48 mmol, 90% yield), yellow oil.

Provenance & Evidence