反応 #9055

反応方程式

2,3-diaminotoluene

trimethylorthoformate

trifluoroacetic acid

→

4-methyl-1H-benzimidazole

溶媒

CH2Cl2

CH2Cl2

反応条件

後処理

1. 1
   洗浄washed consecutively with saturated aqueous NaHCO3 (40 mL) and H2O (40 mL)
2. 2
   乾燥The combined organic extracts were dried over MgSO4
3. 3
   濃縮concentrated to a rusty brown solid (1.07 g, 97%)

実験手順

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).

出典