Phenyl isocyanate → HCID 67928887, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of (5RS, 6SR)-2-[4-(ethylthio)phenyl]-6-phenyl-5,6-dihydro-4H-1,3-oxazin-5-ol (6.5 g) and phenylisocyanate (2.6 g) in 1,2-dichloroethane (100 cc) is heated to a temperature in the region of 80° C. for 5 hours. After being cooled, the reaction mixture is concentrated to dryness under reduced pressure (2.7 kPa) and the residue obtained is purified by chromatography on silica (0.063-0.2 mm; 150 g) contained in a column 3.5 cm in diameter eluting in 20-cc fractions with an ethylacetate/cyclohexane mixture (50:50 by volume). Fractions 5 to 15 are combined and concentrated to dryness under reduced pressure (2.7 kPa). The residue obtained is further purified by chromatography on silica (0.063-0.2 mm; 100 g) contained in a column 3.5 cm in diameter, eluting in 25-cc fractions with a methylene chloride/methanol mixture (99:1 by volume). Fractions 10 to 18 are combined and concentrated to dryness under reduced pressure. (5RS, 6SR)-2-[4-(Ethylthio)phenyl]-6-phenyl-5-phenylcarbamoyloxy-5,6-dihydro-4H-1,3-oxazine (1.1 g), m.p. 70° C., is thereby obtained.

Provenance & Evidence