Application background and overview of 3-amino-2-bromo-6-chloropyridine
3-Amino-2-bromo-6-chloropyridine can be used as a pharmaceutical synthesis intermediate. If 3-amino-2-bromo-6-chloropyridine is inhaled, move the patient to fresh air; if there is skin contact, take off contaminated clothing, rinse the skin thoroughly with soap and water, and seek medical attention if you feel unwell. ; If eye contact occurs, separate eyelids, rinse with running water or saline, and seek medical attention immediately; if ingested, rinse mouth immediately, do not induce vomiting, and seek medical attention immediately.
Application and preparation of 3-amino-2-bromo-6-chloropyridine
The preparation of 3-amino-2-bromo-6-chloropyridine is as follows:
The specific steps are: to a mixture of 6-chloropyridin-3-amine (5g, 38.9mmol) and NaOAc (6.37g, 77.8mmol) in AcOH (30mL), add bromine (6.8g, 42.8 mmol) solution. AcOH (5mL). The resulting reaction mixture was stirred at room temperature for 18 hours. The acetic acid was removed under reduced pressure to obtain a residue, which was dissolved in EA (50 mL) and washed with NaHCO3 aqueous solution (20 mL rubidium carbonate × 5), water and brine. The organic layer was dried over Na2SO4 and the desiccant was filtered off. The filtrate was concentrated in vacuo to give the crude product, which was purified by silica gel chromatography (silica gel, eluting with 5% methanol in DCM) to give 3-amino-2-bromo-6-chloropyridine (5 g, 62% ), as an orange solid. HPLC/UV purity: 90%; LC-MS (ESI): 207.3 (M+1)+.
Applications of 3-amino-2-bromo-6-chloropyridine
3-Amino-2-bromo-6-chloropyridine can be used as a pharmaceutical synthesis intermediate. If the following reaction occurs:
The specific steps are: add 3-amino-2-bromo-6-chloropyridine (5g, 24.4mmol), Pd(OAc)2 (1.09g, 4.88mmol), PPh3 (1.91g, 7.32mmol) and tris To a mixture of ethylamine (10.8 g, 107.3 mmol in DMF (30 mL) under N2 atmosphere), 2-oxopropionic acid (5.69 g, 64.6 mmol) was added via syringe. The resulting mixture was heated at 115°C for 18 hours under N2. The reaction mixture was cooled to room temperature and poured into water (200 mL). The resulting precipitate was filtered, and the filtrate was washed with EA (30 mL × 3). Adjust the pH of the aqueous phase with 1N aqueous solution. The HCl solution was adjusted to pH 4, and the resulting precipitate was collected by filtration and dried under reduced pressure to obtain 5-chloro-1H-pyrrolo[3,2-b]pyridine-2-carboxylic acid (2.44g, 51%) as a solid. HPLC/UV purity: 90%; LC-MS (ESI): 197.1 (M+1)+
