Phosphorus oxychloride → 6-chloro-1-(2-isocyanobenzyl)-3-methylpyrimidine-2,4(1H,3H)-dione

Participants

Reaction Steps

In an alternate embodiment, a solution of 1-(2-isocyanobenzyl)-3-methylpyrimidine-2,4,6(1H,3H,5H)-trione (18 mmol), phosphorus oxychloride (85 ml), benzyltriethylammonium chloride (16.5 g, 72 mmol) and phosphorus pentachloride (3.8 g, 18 mol) in acetonitrile (80 ml) was refluxed for 4-5 h with stirring. After evaporation under reduced pressure, the resulting oily residue was mixed with methylene chloride (or chloroform) and the mixture was poured into water and ice (50 ml). The layers were separated and the aqueous layer was extracted with dichloromethane (200 ml). The combined organic extracts were washed with water and brine, dried over sodium sulphate and concentrated under reduced pressure. Crude product was crystallized from THF-hexanes to give desired compound in 70.5% yield.

Provenance & Evidence