Triethylamine → 6,6-Dimethyl-3-(5-(phenylethynyl)pyrazin-2-yl)-1,3-oxazinan-2-one

Participants

Reaction Conditions

Reaction Steps

A solution of 2-methyl-4-(5-(phenylethynyl)pyrazin-2-ylamino)butan-2-ol (Example 168, step 2) (84 mg, 0.30 mmol) and triethylamine (91 mg, 125 μl, 0.90 mmol, 3 equiv.) in 2 ml of THF was cooled to 0-5° C. and triphosgene (89 mg, 0.30 mmol, 1 equiv.) was added in portions. The mixture was stirred for 1 hr at 0-5° C. and for 2 hours at room temperature. The reaction mixture was quenched with saturated sodium carbonate solution followed by workup with ethyl acetate/water. The organic layers were combined, dried and concentrated. The crude product was chromatographed over a prepacked 20 g Silica column eluting with a heptane to 50% ethyl acetate in heptane gradient to yield the title compound (66.1 mg, 72% yield) as an off-white solid, MS: m/e=308.3 (M+H+).

Provenance & Evidence