Citric Acid → 4-((1R,3S)-3-Hydroxycyclohexylamino)-2-(methylthio)pyrimidine-5-carboxylic acid

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Reaction Steps

To a stirring solution of ethyl 4-((1R,3S)-3-hydroxycyclohexyl-amino)-2-(methylthio)pyrimidine-5-carboxylate (5 g, 16.06 mmol) in ethanol (50 ml) was added 2M sodium hydroxide (20 ml, 40.0 mmol). Stirring was continued at room temperature for 1 h. The reaction mixture was neutralized by addition of saturated citric acid. The resulting precipitate was filtered and dried to afford 4-((1R,3S)-3-hydroxycyclohexyl-amino)-2-(methylthio)pyrimidine-5-carboxylic acid (4.5 g, 15.88 mmol, 99% yield) as a white solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 13.21 (br. s., 1H), 8.44-8.54 (m, 2H), 4.74 (d, J=3.90 Hz, 1H), 3.97-4.12 (m, 1H), 3.56 (d, J=3.12 Hz, 1H), 2.46 (s, 3H), 2.05-2.16 (m, 1H), 1.84 (d, J=10.15 Hz, 1H), 1.65-1.80 (m, 2H), 1.11-1.36 (m, 4H). MS (ESI) m/z 284.1 [M+1]+.

Provenance & Evidence