2-Chloro-1H-imidazole

61278-81-7

16265-04-6

The general procedure for the synthesis of 2-chloroimidazole from 1-(diethoxymethyl)imidazole is as follows: with reference to Example 9, 2-chloroimidazole was prepared as follows: N-(diethoxymethyl)imidazole (50.0 g) was dissolved in tetrahydrofuran (200 ml), and a n-hexane solution of 2.6 M n-butyllithium (120 ml) was added slowly and dropwise to this solution. The addition of tetrahydrofuran solution (100 ml) of hexachloroethane (73.9 g) was continued dropwise at -35°C. The reaction mixture was kept at the same temperature for 5 min, then warmed up to -20°C and 6N hydrochloric acid (100 ml) was added, after which it was restored to room temperature and left to stand for 5 min. The aqueous layer was separated and the organic layer was extracted with 1N hydrochloric acid, the extract was combined with the aqueous layer and washed with ether. This was followed by neutralization with 6N aqueous sodium hydroxide and extraction with ethyl acetate. The organic layer was separated, dried with anhydrous magnesium sulfate and the solvent was removed by distillation to give the crude product. The crude product was ground with dichloromethane to give finally 2-chloroimidazole (26.0 g, yield: 85.0%) as a light brown solid.1H-NMR (CDCl3) δ (ppm): 10.64 (1H, bs), 7.05 (1H, s).