Phosgene → 7-isocyanato-4-methyl-2H-chromen-2-one

Participants

Reaction Steps

A round bottom flask was charged with 7-amino-4-methyl-coumarin (50 mg, 0.285 mmol) under argon and treated with a 20% phosgene in toluene solution (2 ml) under. The reaction mixture was heated at reflux for 15 hrs under argon during which time a white solid precipitated out of solution. After cooling, the excess phosgene was removed by bubbling argon gas through from the solution for 10 minutes. The reaction mixture was then evaporated to afford the product as white solid, which was used directly in the next step. Yield: 50 mg (87%).

Provenance & Evidence