Ethyl formate → 5-(2,4-Difluorophenoxy)-2-methylsulfanylpyrimidin-4-ol

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Reaction Steps

To a solution of 2-(2,4-difluorophenoxy)acetic acid ethyl ester (8.0 g, 37.01 mmol) and ethyl formate (4.11 g, 55.51 mmol) in dry THF (200 mL) was added NaH (1.55 g, 38.75 mmol) slowly at 0° C. The mixture was then refluxed for 2 h. In a separate flask, sodium ethoxide (3.02 g, 44.41 mmol) and S-methylthiopseudourea hemisulfate (6.17 g, 44.41 mmol) in EtOH (100 mL) were stirred at 20° C. for 2 h and then the resulting mixture was added to the above THF solution. The combined mixture was refluxed for 12 h. After concentration under vacuum, water (20 mL) and HCl (10 mL, aq. 1N) were added. The suspended solids were collected and washed with water (50 mL×3) and EtOH (50 mL×3) and dried to give the title compound (6.0 g, 60.0% yield) as a light yellow solid. 1H NMR (DMSO-d6, 400 MHz) δ 7.84 (s, 1H), 7.42-7.34 (m, 1H), 7.04-7.01 (m, 1H), 6.95 (t, J=9.6 Hz, 1H), 2.47 (s, 3H).

Provenance & Evidence