3-Aminopyridine → 5-[2-(Pyridin-3-ylamino)-pyrimidin-4-yl]-thiophene-2-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

Palladium II acetate (8.3 mg, 0.1 mmol) and xantphos 42.8 mg, 0.2 mmol) were precombined in 4 mL dry dioxane under nitrogen gas. Potassium carbonate (1.03 g, 7.46 mmol) was added followed by a solution of 5-(2-Chloro-pyrimidin-4-yl)-thiophene-2-carboxylic acid ethyl ester (100 mg, 0.373 mmol) and 3-aminopyridine (42 mg, 0.447 mmol) in 3 mL dioxane. The reaction was heated in a capped vial at 100° C. for 20 h. The cooled reaction mixture was diluted with EtOAc and water and the layers were separated. The organic layer was dried over Na2SO4 and concentrated in vacuo. The residue was redissolved in ethyl ether and treated with 2 M HCl in ether to generate a precipitate which was collected by filtration to afford 76 mg (56.3%) of the title compound. The crude material was used in the next step.

Provenance & Evidence