The main application background and overview of 2-amino-6-chloro-5-bromopyridine
2-Amino-6-chloro-5-bromopyridine can be used as a pharmaceutical synthesis intermediate.
Main application preparation of 2-amino-6-chloro-5-bromopyridine
2-Amino-6-chloro-5-bromopyridine is prepared as follows:
The specific steps are as follows: Weigh 6-chloro-pyridin-2-amine (2.58g, 20.06mmol), add it to N,N-dimethylformamide (25mL) and dissolve it, weigh N-bromobutyl Diimide (3.56g, 20.00mmol) was added to the above solution, and the reaction was carried out at room temperature for 0.5 hours. Add water, extract with ethyl acetate, wash the organic phase with saturated brine, dry over anhydrous sodium sulfate, and concentrate. The crude product is purified by silica gel column chromatography (petroleum ether: ethyl acetate = 5:1) to obtain the title compound (3.60 g, product rate 86.5%).
Main applications of 2-amino-6-chloro-5-bromopyridine
2-Amino-6-chloro-5-bromopyridine can be used as a pharmaceutical synthesis intermediate, if the following reaction occurs:
The specific steps are as follows: Weigh 5-bromo-6-chloropyridin-2-amine (3.30g, 15.90mmol) and add it to ethanol (10mL), then add 20% mass fraction of sodium methylmercaptide aqueous solution (13mL, 37.09mmol), raise the temperature to 110°C and seal the tube for 18 hours. The reaction solution was cooled to room temperature, water (100 mL) was added, and extracted with dichloromethane (300 mL). The organic phase was washed with saturated brine (100 mL), dried over anhydrous sodium sulfate, and concentrated. The crude product was subjected to silica gel column chromatography (petroleum ether: acetic acid). Ethyl ester=5:1) was purified to obtain the title compound (3.35g, yield 96.2%). Weigh 5-boronic acid-10B-bromo-6-(methylthio)pyridin-2-amine (3.24g, 14.79mmol), dissolve it in acetone (30mL) and glacial acetic acid (15mL), and add potassium permanganate (6.21 g, 39.30 mmol) was dissolved in water (50 mL) and then added dropwise to the above solution. After the dropwise addition, the reaction was carried out at room temperature for 16 hours. Add water (150 mL), extract with ethyl acetate (200 mL Purification by column chromatography (dichloromethane: methanol = 50:1) gave the title compound (1.73 g, calcium carbonate yield 46.6%).
