1-Methylimidazole → 1-methyl-2-(4-methyl-1H-5-pyrazolyl)-1H-imidazole

Beteiligte Stoffe

Reaktionsschritte

A 100 ml two-necked reaction flask is dried under vacuum and baked by fire and then cooled by nitrogen gas flow. 50 ml of anhydrous tetrahydrofuran and 1-Methylimidazole (10 mmol, 0.8 ml) are added. n-Butyl lithium agent (12 mmol, 4.8 ml) is slowly added at −78° C. After the reaction has been taken place for 15 minutes, ethyl methyl carbonate (12 mmol, 1.25 g) is added into the flask to react at the room temperature. Extraction with ether and water is carried out and the organic layer is concentrated to obtain a liquid product. The yield is 95%. The obtained product is then reacted with N,N-Dimethylformamide dimethyl acetal (14.25 mmol, 1.89 ml) without any solvent at 100° C. for 10 hrs. Extraction with methylene chloride and water is carried out and the organic layer is concentrated to obtain solids. The yield is 93%. The obtained product is dissolved in ethanol and then added with hydrazine (33.13 mmol, 1.61 ml). The reaction is carried out for 3 hrs at 90° C. The reaction solution is concentrated and extracted by methylene chloride and water. The organic layer is concentrated and separated by n-hexane and ethyl acetate through chromatographic column. The product 4mimp is thus obtained and the yield is 68%. 1H NMR (400 MHz, CD2Cl2): δ 7.44 (d, 1 H, J=0.8 Hz), 7.05 (d, 1 H, J=1.2 Hz), 6.95 (d, 1 H, J=1.2 Hz), 3.87 (s, 3 H), 2.29 (d, J=0.8 z, 3H).

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