Phenyl isocyanate → HCID 14650707, compound

Participants

Reaction Steps

Phenyl isocyanate (1.6 g) is added at a temperature in the region of 20° C. to a solution, maintained under an argon atmosphere, o[(5RS, 6SR)-2-(4-nitrophenyl)-6-phenyl-5,6-dihydro-4H-1,3-oxazin-5-ol (4.1 g) in 1,2-dichloroethane (45 cc). The solution obtained is heated to reflux for 4 hours and then concentrated to dryness under reduced pressure (2.7 kPa). The residue is purified by chromatography on silica (0.063-0.2 mm; 100 g) contained in a column 2.5 cm in diameter [eluent: dichloromethane/methanol (97:3 by volume)], collecting 20-cc fractions. Fractions 10 to 31 are combined and concentrated to dryness under reduced pressure (2.7 kPa) at 40° C. After recrystallization in acetonitrile, (5RS, 6SR)-2-(4-nitrophenyl)-6-phenyl-5-phenylcarbamoyloxy-5,6-dihydro-4H-1,3-oxazine (1.35 g), m.p. 170° C., is obtained.

Provenance & Evidence