Application background and overview of 4-amino-2-bromo-6-methylpyridine
4-Amino-2-bromo-6-methylpyridine can be used as an intermediate in organic synthesis. If 4-amino-2-bromo-6-methylpyridine is inhaled, move the patient to fresh air; if skin contact occurs, remove contaminated clothing and rinse the skin thoroughly with soap and water. If discomfort occurs, remove Seek medical attention; 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.
Applications of 4-amino-2-bromo-6-methylpyridine
4-Amino-2-bromo-6-methylpyridine can be used as an intermediate in organic synthesis. For example, to prepare 2,4-dibromo-6-methylpyridine, the specific steps are as follows: add 4-amino-2-bromo-6-methylpyridine (1.0g, 5.4mmol) cooled to -10°C in 40% HBr To a solution of aqueous solution (1.0 mL) was added bromine (2.57 g, 16.2 mmol) and then slowly dissolved sodium nitrite (1.86 g, 27.0 mmol) in water (3.0 mL). The reaction mixture was warmed to room temperature and stirred for 3 hours. After this time, saturated aqueous sodium bicarbonate solution was added and the reaction mixture was extracted with EtOAc (2×40 mL). The combined organic layers were washed with saturated aqueous sodium thiosulfate solution (2×40 mL) and water (2×40 mL). The organic layer was dried over sodium sulfate, filtered and concentrated. The resulting crude product was purified using a Redisep 12g silica gel column (0 to 100% EtOAc/hexane) to give 2,4-dibromo-6-methylpyridine as a colorless oil. XH NMR (300 MHz, CDCl 3) δ 7.49 (d, J = 1.2 Hz, 1H), 7.28 (d, J = 1.2 Hz, 1H), 2.51 (s methoxypyridine, 3H).
Application and preparation of 4-amino-2-bromo-6-methylpyridine
The preparation of 4-amino-2-bromo-6-methylpyridine is divided into the following steps:
Step 1: To a solution of 2-bromo-6-methylpyridine (2.0g, 1.17mmol) in CH 2 Cl 2 (150 mL) at room temperature was added 3-chloroperoxybenzoic acid (4.5g, 26.3mmol) ). The resulting mixture was stirred at room temperature for 3 hours. After this time, the reaction mixture was diluted with dichloromethane (50 mL) and washed with 6N aqueous sodium hydroxide solution (2×40 mL). The organic layer was concentrated to obtain 2-bromo-6-methylpyridine 1-oxide.
Step 2: Add a 1:1 mixture of sulfuric acid and nitric acid to a solution of 2-bromo-6-methylpyridine 1-oxide (1.95g, 10.4mmol) in sulfuric acid (2.0ml), and then react in Heat at 80°C for 3 hours. After this time, the reaction mixture was diluted with water (50 mL) and the pH was adjusted to pH 7 with saturated aqueous sodium bicarbonate solution. The resulting mixture was extracted with EtOAc (3 x 50 mL). The combined organic layers were dried over sodium sulfate, filtered and concentrated under reduced pressure to obtain 2-bromo-6pyridinemethylamine-methyl-4-nitropyridine as a yellow solid.
Step 3: To a solution of 2-bromo-6-methyl-4-nitropyridine (1.5g, 6.91mmol) in acetic acid (10mL) at room temperature was added iron (1.34g, 2.41mmol). The reaction was then heated at 100°C for 3 hours. After this time, the reaction mixture was diluted with methanol (50 mL) and filtered through celite. The filtrate was concentrated and suspended in 6N aqueous NaOH solution (50 mL). The resulting mixture was extracted with EtOAc (2 x 40 mL). The combined organic layers were dried over sodium sulfate, filtered and concentrated under reduced pressure to obtain 4-amino-2-bromo-6-methylpyridine as a brown solid.
