反应详情

温度

90 °C

2-Hydroxypropanenitrile (26-1) (5.0 g, 70 mmol, 1 eq) in toluene (60 mL) was added dropwise to a stirring solution of oxalyl chloride (24.6 mL, 281 mmol, 4 eq) in toluene (165 mL) at 0° C. After 30 minutes, the reaction mixture was heated to 90° C. and triethylamine hydrochloride (4.8 g, 35.2 mmol, 0.5 eq) was added. The mixture stirred for 4 hours at the same temperature and then was concentrated in vacuo at 60° C. The resulting mixture was suspended in Et2O (300 mL), filtered washing with Et2O (3×100 mL), and the filtrates were combined and concentrated. Purification by flash chromatography (330 g SiO2, 0-50% EtOAc in hexanes) afforded 3,5-dichloro-6-methyl-2H-1,4-oxazin-2-one (26-2) as a white solid. 1H NMR (400 MHz, CDCl3): δ 2.38 (s, 3H).

1. concentrationwas concentrated in vacuo at 60° C
2. filtrationfiltered
3. washwashing with Et2O (3×100 mL)
4. concentrationconcentrated
5. customPurification by flash chromatography (330 g SiO2, 0-50% EtOAc in hexanes)