Phosgene → HCID 13363520, compound

Participants

Reaction Steps

To a solution of 6-amino-8-ethoxy-1,3-benzodioxane (1.95 g) in toluene (20 ml), a toluene solution containing phosgene (10 g) was dropwise added at 10° to 20° C. The resultant mixture was heated gradually and, after being refluxed for 30 minutes, cooled to room temperature. The solvent was removed in vacuo, whereby crude 8-ethoxy-1,3-benzodioxan-6-ylisocyanate was obtained. This crude substance was dropwise added to a toluene solution (50 ml) containing triethylamine (1.0 g) and 2-fluoroethanol (0.70 g) at room temperature. The resultant mixture was allowed to stand at room temperature for 12 hours, poured into ice-water and extracted with ethyl acetate. The extract was washed with water, dried over magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel chromatography using a mixture of toluene and ethyl acetate as the eluent to give 2-fluoroethyl N-(8-ethoxy-1,3-benzodioxan-6-yl)carbamate (Compound No. 10) (2.31 g) in a yield of 80.9%. M.P., 154° -154.5° C.

Provenance & Evidence