4-Methylmorpholine → N-methoxy-N-methyloxane-4-carboxamide

Participants

Reaction Steps

To a solution of tetrahydro-2H-pyran-4-carboxylic acid 1 (4.0 g, 31 mmol) in DCM (65 mL) was added sequentially N,O-dimethylhydroxylamine hydrochloride (3.3 g, 34 mmol), 4-methylmorpholine (7.4 mL, 68 mmol), and N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (6.5 g, 34 mmol). The resulting mixture was stirred at RT for 18 h. At that time, the reaction was diluted with 1N HCl and EtOAc and stirred vigorously until both phases cleared. The phases were separated, and the aqueous layer was extracted with EtOAc. The organic portions were combined, washed with brine, dried over MgSO4, filtered, and concentrated. The crude residue was subjected to column chromatography (120 g silica, 80 ml/min, 0% to 100% EtOAc/hexanes) to give N-methoxy-N-methyltetrahydro-2H-pyran-4-carboxamide 2 (4.3 g, 24.8 mmol, 81%). LCMS for 2 (conditions D): tR=1.12 min, m/e=174.3 (M+H, base).

Provenance & Evidence