Diphosgene → 6-Fluoro-5-isocyanato-3-propargyl-2-benzothiazolone

Participants

Reaction Steps

To a solution consisting of 3.2 g of 5-amino-6-fluoro-3-propargyl-2-benzothiazolone and 50 g of dioxane were dropwise added 2.4 g of trichloromethyl chlorocarbonate at a temperature in the range of from 5° to 15° C. and the resulting mixture was heated under reflux for six hours. A residue was obtained by distilling off the low-boiling material from the mixture under reduced pressure, and it was dissolved in 150 ml of dried toluene and filtered. From the resulting filtrate toluene was distilled off to obtain 3.6 g of 6-fluoro-5-isocyanato-3-propargyl-2-benzothiazolone having a melting point in the range from 134° to 135° C.

Provenance & Evidence