Carbon Dioxide → Vitalethine

Participants

Reaction Steps

To a suspension of ZnO (6.5 mg from King's Specialty Company, Fort Wayne, Ind. U.S.A.) and β-alethine (6.35 mg from Example IV. A. above) in pyridine (12.6 mg from Fisher Scientific, Fair Lawn, N.J., U.S.A.) and dimethylsulfoxide (0.5 ml from Sigma Chemical Company, St. Louis, Mo., U.S.A.), and in a vessel equipped with a gas trap containing sodium hydroxide (at least 1M), was added 0.2 ml of a solution of phosgene (20% in toluene from Fluka Chemical Corp. Ronkonkoma, N.Y., U.S.A.). Packing of the reaction vessel in dry ice controls the exothermic reaction and improves the yields of large-scale preparations. After 48 hours of reaction the excess phosgene was blown into the alkali trap with N2. The product was precipitated in the vessel with acetonitrile (approximately 50 ml from Fisher Scientific, Fair Lawn, N.J., U.S.A.). Vitalethine can be recrystallized from water with acetonitrile.

Provenance & Evidence