Preparation method of 1-(4-pyridyl)ethylamine dihydrochloride_Industrial additives

Overview of the preparation method of 1-(4-pyridyl)ethylamine dihydrochloride

1-(4-pyridyl)ethylamine dihydrochloride is an organic intermediate, which is the hydrochloride form of 1-(4-pyridyl)ethylamine and can be synthesized from 1-(4-pyridyl) Prepared from ethylamine and hydrogen chloride.

Preparation method of 1-(4-pyridyl)ethylamine dihydrochloride Preparation method

Method 1: Add sodium cyanoborohydride (0.7g in one go, 11.1 mmol). The reaction mixture was stirred at room temperature overnight. After removing the methanol, water (20 mL) was added to the residue and the resulting solution was basified to pH = 13 by adding sodium hydroxide. The aqueous solution was extracted with dichloromethane and the combined organic phases were dried over sodium sulfate. The solvent was removed under reduced pressure to obtain 1-(4-pyridyl)ethylamine.

Method 2,

Step 1. Add 4-acetylpyridine (1.9 g, 10 mmol), 95% EtOH (15 mL), hydroxylamine hydrochloride (1.0 g, 15 mmol, 1.5 equiv) and Et_{3 Nitropyridine}N (2.1 mL, 15 mmol, 1.5 equiv). The mixture was heated in a microwave reactor at 120°C for 20 minutes. Remove EtOH in vacuo. Post-treatment (hydroxymethylpyridine EtOAc/H₂O) gave 1-(pyridin-4-yl)ethanone oxime (620 mg, 46%) as a white solid.

Step 2. Add oxime (200 mg, 1.5 mmol), 95% EtOH (15 mL), ammonium hydroxide (0.3 mL) and Raney nickel (300 mg) to the Parr shaking flask. The mixture was shaken at room temperature in a hydrogen atmosphere (50 PSI) for two days. The reaction was filtered through Celite and washed with MeOH. The solution was evaporated. 1-(4-pyridyl)ethylamine (140 mg, 78%) was obtained as a white solid.