Phenyl isocyanate → HCID 14650693, compound

Participants

Reaction Steps

Phenyl isocyanate (1.25 g) is added at a temperature in the region of 20° C. to a solution, maintained under an argon atmosphere, of (5RS, 6SR)-2-(4-methoxyphenyl)-6-phenyl-5,6-dihydro-4H-1,3-oxazin-5-ol (1.5 g) in 1,2-dichloroethane (20 cc). The solution obtained is heated to reflux for 6 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; 50 g) contained in a column 2 cm in diameter [eluent: cyclohexane/ethyl acetate/triethylamine (60:35:5 by volume)], collecting 20-cc fractions. Fractions 4 to 10 are combined and concentrated to dryness under reduced pressure (2. 7 kPa) at 40° C. After recrystallization in diisopropyl ether, (5RS, 6SR)-2-(4-methoxyphenyl)-6-phenyl-5-phenylcarbamoyloxy-5,6-dihydro-4H-1,3-oxazine (0.52 g), m.p. 223° C., is obtained.

Provenance & Evidence