Hydrochloric Acid → 7-[(8-Cyclopentyl-7,7-diethyl-5-methyl-6-oxo-pteridin-2-yl)amino]-2,3-dihydrobenzofuran-4-carboxylic acid

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Reaction Steps

2-Chloro-8-cyclopentyl-7,7-diethyl-5-methyl-pteridin-6-one 42a (100 mg, 0.31 mmol) and methyl 7-amino-2,3-dihydrobenzofuran-4-carboxylic acid 1g (50 mg, 0.28 mmol) were dissolved in 17 mL of the mixture solvent of ethanol and water (V/V=5:12) followed by the addition of 0.2 mL of concentrated hydrochloric acid. The reaction mixture was heated to reflux for 16 hours with stirring. The resulting solution was concentrated under reduced pressure, added dropwise with 1 M lithium hydroxide solution to adjust pH to 12 and extracted with ethyl acetate (50 mL×2), the combined aqueous phase was added dropwise with 1 M hydrochloric acid to adjust pH to 1 and extracted with dichloromethane (50 mL×3). The combined organic phase was dried over anhydrous magnesium sulfate, filtered and the filtrate was concentrated under reduced pressure to obtain 7-[(8-cyclopentyl-7,7-diethyl-5-methyl-6-oxo-pteridin-2-yl)amino]-2,3-dihydrobenzofuran-4-carboxylic acid 42b (50 mg, yield: 38.0%) as a yellow solid.

Provenance & Evidence