Phosgene → 4-Chloro-6-(4-isocyanatophenoxy)pyrimidine

Participants

Reaction Conditions

Reaction Steps

Apparatus: 2 litre 3-neck-roundbottle flask, dropping funnel, short Vigreux column and condenser. A phosgene solution (20% in toluene, 118 ml; 223 mmol) diluted with toluene (800 ml) under N2-atmosphere is cooled to approximately −20° C. Then a solution of 4-(6-chloro-pyrimidin-4-yl-oxy)-aniline (Stage 21.1; 18.52 g, 83.6 mmol) in CH2Cl2 (400 ml) is added dropwise. The resulting suspension is heated to distil off approximately 400 ml of solvent. Distillation Is continued (boiling point: 110° C.), while a mixture of phosgene solution (20% in toluene, 59 ml) and toluene (500 ml) is added dropwise, followed by toluene (250 ml). The resulting clear solution (a 250 ml) in the reaction vessel is cooled to rt, filtered and the filtrate concentrated in vacuo. Distillation of the resulting waxy crude product on the Kugelrohr apparatus (0.2 mbar, 200° C.) gives the title compound as a solid: m.p.: 103° C.; MS: [M+1]+=302; 1H-NMR (CDCl3): 8.57 (s, 1H), 7.17 (d, 2H), 7.10 (d, 2H), 6.95 (s, 1H).

Provenance & Evidence