ChemicalBook CAS DataBase List 4-bromo-2-ethylpyridine

4-bromo-2-ethylpyridine synthesis

6synthesis methods

Product Name:4-bromo-2-ethylpyridine
CAS Number:156761-88-5
Molecular formula:C7H8BrN
Molecular Weight:186.05

1060805-69-7
80 suppliers
$93.59/250mg

156761-88-5
59 suppliers
$55.00/10mg

Yield:156761-88-5 91.4%

Reaction Conditions:

with aluminum (III) chloride;sodium tetrahydroborate in tetrahydrofuran at -5 - 65; for 12 h;Inert atmosphere;Temperature;

Steps:

1; 4-5; 1-2 Synthesis of 2-ethyl-4-bromopyridine

Add 50.0g (0.25mol, 1eq) of 1-(4-bromopyridin-2-yl)ethanone and 400g of tetrahydrofuran to a 1000ml four-necked reaction flask, start stirring, The reaction flask was replaced with nitrogen for protection, the temperature was reduced to -5°C, 14.2g (0.375mol, 1.5eq) of sodium borohydride and 66.7g (0.5mol, 2eq) of aluminum trichloride were added, After the addition, the temperature is slowly raised to 0°C and the reaction is stirred for 2h, and then heated to reflux (about 65°C) for 10h (detection of raw materials The solvent was removed under reduced pressure, and 300 g of water was slowly added dropwise to the residue under the protection of nitrogen, and the temperature was controlled not to exceed 35°C in an ice water bath. After dripping, it was stirred for 2h in an ice-water bath, extracted with chloroform 300g×2, combined the organic phases, and dissolved, the residue was 46.4g, recrystallized with ethanol 139.2g to obtain 42.5g of 2-ethyl-4-bromopyridine. The purity measured by HPLC was 98.4%, and the yield was 91.4%.

References:

CN112194620,2021,A Location in patent:Paragraph 0016; 0020; 0026-0027; 0029-0030

925-90-6 Synthesis