Diphosgene → 1-(2-ethylbutyl)-2H-pyrido[2,3-d][1,3]oxazine-2,4(1H)-dione

Participants

Reaction Steps

The product of Example 3A (0.664 g, 2.65 mmol) and diphosgene (1.57 g, 7.96 mmol) in 13 mL of 1,2-dichloroethane and 1.3 mL of 1,4 dioxane were reacted at 80° C. for 16 hours. The reaction was concentrated under vacuum and the residue was purified by flash column chromatography on silica gel eluting with hexane/ethyl acetate (9:1) to provide the title compound (0.235 g, 36%). 1H NMR (300 MHz, CDCl3) δ 0.95 (m, 6H), 1.40 (m, 4H), 1.52 (m, 2H), 4.21 (m, 1H), 7.25 (m, 1H), 8.41 (dd, J=7.72, 1.84 Hz, 1H), 8.70 (dd, J=4.78, 1.84 Hz, 1H).

Provenance & Evidence