Trifluoroacetic acid → 4-Methylbenzimidazole

To a stirred solution of 2,3-diaminotoluene (1.00 g, 8.2 mmol) in CH2Cl2 (82 mL) was added trimethylorthoformate (4.5 mL, 41 mmol) and trifluoroacetic acid (0.32 mL, 4.1 mmol) and the mixture stirred at room temperature for 24 h after which the reaction mixture was diluted with CH2Cl2 (200 mL), and washed consecutively with saturated aqueous NaHCO3 (40 mL) and H2O (40 mL). The aqueous layers were reextracted with CH2Cl2 (2×100 mL). The combined organic extracts were dried over MgSO4 and concentrated to a rusty brown solid (1.07 g, 97%). 1H NMR (300 MHz, CDCl3) δ 8.08 (s, 1H), 7.49 (d, 1H, J=8.1 Hz), 7.23–7.18 (m, 1H), 7.10 (d, 1H, J=7.5 Hz), 2.64 (s, 3H).

1. washwashed consecutively with saturated aqueous NaHCO3 (40 mL) and H2O (40 mL)
2. dry with materialThe combined organic extracts were dried over MgSO4
3. concentrationconcentrated to a rusty brown solid (1.07 g, 97%)

ORD-Eintrag

ord-bf56584023f540c7948984614ab8fea3

Quelldatensatz

uspto-grants-2006_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07091217B2