Phosgene → 3,4-Difluorophenyl isocyanate

Participants

Reaction Conditions

Reaction Steps

At -10° to 0° and while stirring, 120 g of 3,4-difluoroaniline (J. Chem. Soc., 73, 5884-5, 1951) is metered into a solution of 180 parts by weight of phosgene in 1,100 parts by weight of chloronaphthalene. The reaction mixture is then slowly heated to 150° C. while passing in additional phosgene, and phosgenated for 2 hours at this temperature. Excess phosgene is expelled with nitrogen and the isocyanate distilled from the solution; b.p. (30 mm Hg): 79°-85° C.

Provenance & Evidence