Background and overview of the preparation method of 4-bromopyridine
4-Bromopyridine is an organic intermediate that can be obtained by bromination of pyridine with lithium carbonate or prepared by diazotization of aminopyridine.
Preparation method of 4-bromopyridine
Report on the preparation method of 4-bromopyridine 1.
Add pyridine, liquid bromine, and ferric bromide into the reaction kettle, and react for 1-1.5 hours under calcium carbonate conditions with a rotation speed of 300-500r/min and a temperature of 40-50°C to obtain the intermediate. 4-Bromopyridine.
Report on the preparation method of 4-bromopyridine 2.
Dissolve aminopyridine (1 mmol) and substituted copper(II) halide in dibromo(chloro)methane (6 ml) under an argon atmosphere at 25°C, and dissolve iso-nitrous acid within 5 minutes. Pentyl ester (1.1 mmol) was added dropwise to the mixture. The reaction mixture was stirred at 25 °C until GC-MS analysis of the reaction mixture showed complete consumption of starting material (16 h). The reaction mixture was added to 1N NaOH (20 mL). Stir the mixture for 1 hour. The mixture was extracted with CH2Cl2 (3 × 20 mL). The combined organic extracts were dried (Na2SO4). The product was evaporated to dryness. The product was purified by column chromatography on silica gel. Elution with CH2Cl2 gave 4-bromopyridine.
References
[1] [Chinese invention] CN202010247567.4 PVC gloves with antibacterial function and preparation method thereof
[2] Tetrahedron Letters, 58(17), 1681-1683; 2017
