p-Toluenesulfonic acid → methyl 7-[[(7R)-8-cyclopentyl-7-ethyl-5-methyl-6-oxo-7H-pteridin-2-yl]amino]-2,3-dihydrobenzofuran-4-carboxylate

Participants

Reaction Steps

(7R)-2-Chloro-8-cyclopentyl-7-ethyl-5-methyl-5H-pteridin-6-one 1o (670 mg, 2.30 mmol), methyl 7-amino-2,3-dihydrobenzofuran-4-carboxylate 1g (440 mg, 2.30 mmol) and p-toluenesulfonic acid (700 mg, 3.68 mmol) were dissolved in 25 mL 4-methyl-2-pentanol. The resulting solution was heated to reflux for 6 hours with stirring. The reaction solution was added with 25 mL of saturated sodium bicarbonate solution, extracted with ethyl acetate (50 mL×3). The combined organic phase was washed with water (50 mL×3) and saturated sodium chloride solution (50 mL×3) successively, then dried over anhydrous sodium sulfate, filtered and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography to obtain the title compound methyl 7-[[(7R)-8-cyclopentyl-7-ethyl-5-methyl-6-oxo-7H-pteridin-2-yl]amino]-2,3-dihydrobenzofuran-4-carboxylate 1p (0.77 g, yield: 74.0%) as a light yellow solid.

Provenance & Evidence