Tetrahydrofuran → 7-fluoro-6-methoxy-1-methyl-1,3-dihydro-2H-benzimidazol-2-one

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Reaction Steps

3-fluoro-4-methoxy-N2-methylbenzene-1,2-diamine (7-3, 1.09 g, 6.40 mmol) was dissolved in anhydrous THF (15 ml) and treated with CDI (1.25 g, 7.69 mmol, 1.2 eq). The resulting orange solution was stirred at reflux for 6 h, then cooled to 23 deg C. The remaining dark reaction mixture was partitioned between EtOAc (2×40 ml) and water (45 ml). The combined organic layers were dried over Na2SO4 and concentrated. The crude mixture was purified via flash column chromatography (SiO2: 100% Hex to 50:50 Hex:EtOAc), affording the title compound, 7-fluoro-6-methoxy-1-methyl-1,3-dihydro-2H-benzimidazol-2-one (7-4), as a maroon oil. 1H NMR (500 MHz, CDCl3) δ 7.11 (s, 1H), 6.68-6.74 (m, 2H), 3.89 (s, 3H), 3.60 (s, 3H). LRMS m/z: Calc'd for C9H9FN2O2(M+H) 197.2, found 196.9.

Provenance & Evidence