Application background and overview of 3-bromo-5-chloropyridine
3-Bromo-5-chloropyridine CAS number 73583-39-8, chemical formula C5H3BrClN. Molecular weight 192.44100. Density 1.736g/cm3, melting point 80-82°C, boiling point 194.7ºC at 760 mmHg, flash point 71.5ºC, refractive index 1.581. 3-Bromo-5-chloropyridine can be used as a pharmaceutical and chemical synthesis intermediate. If 3-bromo-5-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 uncomfortable; if the eyes are clear, In case of contact, 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 structure of 3-bromo-5-chloropyridine
Applications of 3-bromo-5-chloropyridine
3-Bromo-5-chloropyridine can be used as an intermediate for pharmaceutical and chemical synthesis, such as the synthesis of 3-chloropyridine derivatives, using 2,3-dichloropyridine, 3-bromo-5-chloropyridine and 2,5 -Dichloropyridine was used as the starting material, and 14 kinds of 3-chloropyridine derivatives were synthesized through three methods: nucleophilic substitution reaction, Suzuki coupling reaction and Buchwald-Hartwig amination reaction. The product structures were analyzed by 1H NMR and GC. -Identification of MS.
For example, the synthesis of 3-chloro-5-cyclopropylpyridine: Add 5-O g (26-0 mm01) 3-bromo-5-chloropyridine and 25.0 g (118.3 mmol) potassium phosphate, then add 120 mL toluene and 6 mL water, and after ultrasonic treatment for 10 minutes, add 126.0 mg (0.6 mmol) palladium acetate, 294.6 mg (1.1 mmol) diphenylphosphine and 1.5 g (16.9 mmol) cyclopropyl boronic acid, heated to 100 oC in a nitrogen atmosphere, and after two hours of reaction, continued to add 126.0 mg (0.6 mmol) palladium acetate, 316.0 mg (1.1 mmol) cyclohexylphosphine and 1-5 g (16.9 mmol) cyclopropyl Boric acid, after reacting for two hours, continue to add 126.0 mg (0.6 mmol) palladium acetate, 294.6 mg (1-1 mmol) triphenylphosphine and 1.5 g (16-9 mmol) cyclopropylboronic acid, and stir for two hours Afterwards, the temperature dropped to room temperature and the reaction was continued for 16 hours.
After the reaction is completed, add ethyl acetate and water, then filter, and separate the organic phase in the filtrate. The aqueous phase was extracted twice with ethyl acetate, the organic phase was collected, and backwashed twice with saturated brine. The organic phase was dried with sodium sulfate, suction-filtered, and concentrated to obtain a crude product. After column separation, 2.3 g of yellow pyridyl acetic acid color solid was obtained (eluent polarity: petroleum ether: ethyl acetate = 50:1), with a yield of 45%.
Nitrophenylboronic acid
