Hydrochloric Acid → 2-(3-Isocyanatophenyl)-4H-3,1-benzoxazin-4-one

Participants

Reaction Steps

40 Parts by weight of 2-(m-aminophenyl)-3,1-benzoxazin-4-one are suspended in 300 parts by volume of chlorobenzene and the suspension is treated with hydrogen chloride gas until saturated therewith, and then with phosgene gas for 4 hours at 110° C. The clear solution is concentrated under reduced pressure and the residue is then washed with ether and petroleum ether, giving 39 parts by weight of 2-(m-isocyanatophenyl)-3,1-benzoxazin-4-one of melting point 115°-121° C.

Provenance & Evidence