Phenylboronic Acid → Methyl 2-(methylthio)-7-phenylthieno[3,2-d]pyrimidine-6-carboxylate

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Reaction Steps

Anhydrous dioxane is added, under argon, to a mixture of 2.5 g of methyl 2-(methylsulfanyl)-7-{[(trifluoromethyl)sulfonyl]oxy}thieno[3,2-d]pyrimidine-6-carboxylate 4 (example 1) and 0.785 g of phenylboronic acid. After the addition of 250 mg of dichloropalladium (dppf) and 4.09 g of BTPP, the mixture is refluxed for 20 h, and then cooled to ambient temperature. The mixture is filtered on silica gel, elution being carried out with ethyl acetate. The solvent is evaporated off under vacuum and the residue is triturated with an ethyl acetate/heptane mixture so as to obtain 1.6 g of methyl 2-(methylsulfanyl)-7-phenylthieno[3,2-d]pyrimidine-6-carboxylate in the form of a whitish precipitate.

Provenance & Evidence