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

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Reaction Steps

(7S)-2-Chloro-8-cyclopentyl-7-ethyl-5-methyl-7H-pteridin-6-one 41f (300 mg, 1.70 mmol) and methyl 7-amino-2,3-dihydrobenzofuran-4-carboxylate 1g (543 mg, 1.80 mmol) were dissolved in 34 mL of the mixture solvent of ethanol and water (V/V=1:2.4) followed by the addition of 0.4 mL of concentrated hydrochloric acid and heated to reflux for 16 hours. The reaction solution was cooled down to room temperature, put into the refrigerator for 1 hour and filtered. The filter cake was washed with water (50 mL) and dissolved in 20 mL of the mixture solvent of water and 1 M lithium hydroxide (V/V=1:1), extracted with ethyl acetate (50 mL×2), the aqueous phase was added dropwise with 1 M hydrochloric acid to adjust pH to 2 resulting in the formation of precipitate. The precipitate was filtered to obtain the title compound 7-[[(7S)-8-cyclopentyl-7-ethyl-5-methyl-6-oxo-7H-pteridin-2-yl]amino]-2,3-dihydrobenzofuran-4-carboxylic acid 41g (0.45 g, yield: 62.0%) as a white solid.

Provenance & Evidence