Dimethylformamide → N-hydroxy-2(R)-[(3,4-methylenedioxybenzyl)-(4-methoxy-2,3,6-trimethylbenzenesulfonyl)amino]-3-methylbutyramide

Participants

Reaction Steps

To a solution of 2(R)-[(3,4-methylenedioxybenzyl)-(4-methoxy-2,3,6-trimethylbenzenesulfonyl)amino]-3-methylbutyric acid (3.82 g, 8.24 mmol) in dry methylene chloride (20 mL) was added oxalyl chloride (2.2 mL, 24.72 mmol) and a drop of dimethylformamide. The reaction mixture was stirred for 4 h and then concentrated. The residue was dissolved in methylene chloride 20 mL) and N,O-bis-trimethylsilylhydroxylamine (8.8 mL, 41.2 mmol) was added. After 4 h, methanol (1 mL) was added and the stirring was continued for 30 min. Silica gel (10 g) was added and the material was concentrated to dryness. The resultant powder was flash chromatographed on a silica gel column and eluted with 50% ethyl acetate/hexanes to give N-hydroxy-2(R)-[(3,4-methylenedioxybenzyl)-(4-methoxy-2,3,6-trimethylbenzenesulfonyl)amino]-3-methylbutyramide (2.46 g).

Provenance & Evidence