Isocyanatocarbonyl chloride → 8-(3,4-difluorophenyl)-7,8-dihydropyrano[3,4-e][1,3]oxazine-2,4(3H,5H)-dione

Participants

Reaction Steps

3-(3,4-difluorophenyl)dihydro-2H-pyran-4(3H)-one (Intermediate Y(2)) was reacted as described in Intermediate X(3) with carbonisocyanatidic chloride to give 8-(3,4-difluorophenyl)-7,8-dihydropyrano[3,4-e][1,3]oxazine-2,4(3H,5H)-dione (Intermediate Y(3)). LC-MS (M+H)+=282.1. 1H NMR (500 MHz, CDCl3) δ ppm 7.08-7.20 (m, 3 H) 4.67 (d, J=15.26 Hz, 1 H) 4.46 (dd, J=15.56, 2.14 Hz, 1 H) 3.98-4.10 (m, 2 H) 3.67 (br. s., 1 H).

Provenance & Evidence