tert-Butyl acrylate → (E)-tert-Butyl 3-(3-(2-ethoxy-2-oxoethyl)-2-oxo-1,2,3,4-tetrahydropyrido[2,3-d]pyrimidin-6-yl)acrylate

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Reaction Steps

tert-Butyl acrylate (1.25 mL, 8.53 mmol), diisopropylethylamine (730 μL, 4.26 mmol) and P(o-tolyl)3 (130 mg, 0.43 mmol) were successively added to a suspension of ethyl 2-(6-bromo-2-oxo-1,2-dihydropyrido[2,3-d]pyrimidin-3(4H)-yl)acetate (670 mg, 2.13 mmol) in propionitrile (11 mL) and dimethylformamide (2.5 mL). The resulting mixture was purged with argon prior to the addition of palladium acetate (48 mg, 0.213 mmol). The mixture was purged with argon a second time and refluxed overnight. The reaction mixture was then filtered on Celite® and washed with ethyl acetate (75 mL) and dichloromethane (75 mL). The filtrate was concentrated to dryness and the residue was partitioned between dichloromethane (50 mL) and water (50 mL). The aqueous phase was separated and extracted with dichloromethane (2×100 mL). The combined organic phases were washed with a saturated solution of sodium chloride (3×100 mL), dried over sodium sulfate, filtered and concentrated to dryness. The residue was precipitated from a mixture dichloromethane/diethylether to afford the title product as a white solid (460 mg, 60%).

Provenance & Evidence