4-Amino-5-bromo-2-chloropyrimidine → 2-Chloro-5-(2-ethoxyvinyl)pyrimidin-4-amine

Beteiligte Stoffe

Reaktionsschritte

To a degassed suspension of 5-bromo-2-chloropyrimidin-4-amine (preparation 37a, 2.50 g, 11.03 mmol) and (Z)-tributyl(2-ethoxyvinyl)stannane (4.76 g, 11.20 mmol) in toluene (40 mL) was added tetrakis(triphenylphosphine)palladium(0) (0.42 g, 0.36 mmol) and the mixture was subjected to several vacuum-argon cycles and then heated to reflux for 24 hours. Further catalyst (0.42 g, 0.36 mmol) was added and the mixture was refluxed an additional 24 hours. Further (Z)-tributyl(2-ethoxyvinyl)stannane (1.20 g, 2.82 mmol) was added and the reaction was refluxed overnight. The mixture was cooled and concentrated in vacuo and the oily residue was treated with hexanes to give a solid which was purified by flash chromatography (4:1 hexanes/ethyl acetate) to give the title compound (0.70 g, 32%) as a white solid.

Herkunft & Nachweise