Ethyl Acrylate → (E)-Ethyl 3-(8-cyclopentyl-4-methyl-2-(methylamino)-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-6-yl)acrylate

Participants

Reaction Conditions

Reaction Steps

6-bromo-8-cyclopentyl-4-methyl-2-(methylamino)pyrido[2,3-d]pyrimidin-7(8H)-one (375 mg, 1.1 mmole), ethyl acrylate (442 mg, 4.42 mmole), N-cyclohexyl-N-methylcyclohexanamine (280 mg, 1.43 mmole), tri-tert-butylphosphonium tetrafluoroborate (9.61 mg, 0.03 mmole), lithium chloride (42.4 mg, 3.3 mmole), tris(dibenzylideneacetone)dipalladium(0)) (30.3 mg, 0.03 mmole) and 1,4-dioxane (10 ml) were added to a reaction vial equipped with a stir bar. The reaction vial was flushed with nitrogen, capped, and heated at 75° C. for 75 min. The reaction mixture was cooled to ambient temperature, filtered through Celite™, and washed with ethyl acetate. The filtrate and washing were combined, and the volatiles were removed under reduced pressure to a yellow solid residue. This solid residue was crystallized from boiling heptane:ethyl acetate (50 ml: 50 ml). Upon cooling to ambient temperature, needle-liked yellow crystals formed and collected by filtration to give the title compound as a beta-trans isomer (356 mg, 90% yield).

Provenance & Evidence