Triethylamine → N~2~-(tert-Butoxycarbonyl)-N-methoxy-N-methyl-D-valinamide

Participants

Reaction Steps

N-Boc-L-valine (3.72 g, 17.2 mmol) and N,O-dimethylhydroxylamine hydrochloride (1.84 g, 18.86 mmol) were dissolved in anhydrous methylene chloride (50 mL) under nitrogen. Triethylamine (2.09 g, 20.64 mmol) was added to the mixture, followed by dropwise addition of diethyl cyanophosphonate (3.09 g, 18.92 mmol). The resulting mixture was stirred at room temperature for 12 h. The reaction was then diluted with methylene chloride (150 mL) and washed with water (100 mL). The aqueous layer was extracted with methylene chloride (50 mL). The combined organic layers were washed successively with aqueous sodium bicarbonate (2×100 mL) and brine (2×100 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The crude residue was carried forward without further purification. 1H NMR (CDCl3): 5.28 (d, 1H), 4.61 (m, 1H), 3.76 (s, 3H), 3.20 (s, 3H), 2.09-1.85 (m, 1H), 1.43 (s, 9H), 0.99 (d, 3H), 0.90 ppm (d, 3H).

Provenance & Evidence