General procedure for the synthesis of 2-(4-iodo-1H-pyrazol-1-yl)-N,N-dimethylethylamine from 4-iodopyrazole and 2-dimethylaminoethyl chloride hydrochloride: 4-iodopyrazole (0.97 g, 5.0 mmol), 2-dimethylaminoethyl chloride hydrochloride (1.4 g, 10 mmol), and potassium carbonate (1.8 g, 15 mmol) were added in N,N-dimethylformamide (15 mL). 2.8 g, 15 mmol). The reaction mixture was stirred at 100 °C for 24 hours. After completion of the reaction, the mixture was cooled to room temperature and the reaction was quenched by the addition of water. The reaction mixture was extracted with ethyl acetate, the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by concentration under reduced pressure and the residue was purified by silica gel column chromatography (Yamazen, eluent: methanol/ethyl acetate) to give 0.42 g (yield: 32%) of the title compound as a brown oil.1H-NMR (400 MHz, CDCl3) δppm: 7.53 (1H, s), 7.50 (1H, s), 4.22 (2H, t, J = 6.3Hz), 2.73 (2H, t, J = 6.3Hz), 2.27 (6H, s).
