22282-99-1

Light yellow liquid

4-Bromo-2-methylpyridine is a starting material used in a synthesis of crown-ester-bipyridines and viologens via sodium or nickel reductive coupling, side chain oxidation and esterification.

4-Bromo-2-methylpyridine is used as a starting material in the preparation of crown-ester-bipyridines and viologens through sodium or nickel reductive coupling, side chain oxidation and esterification. Further, it serves as an important raw material and intermediate in organic synthesis, pharmaceuticals, agrochemicals and in dyes.

Used in the preparation of phenyloxadiazolyl pyridines as immunomodulating agents.

2-Methyl-4-aminopyridine (152) (10.1 g, 93.4 mmol) was used as a raw material, which was dissolved in 48% aqueous hydrobromic acid (165 mL) at -10°C and stirred to form a solution. An aqueous solution of sodium nitrite (7.04 g, 0.102 mol) pre-cooled to 0°C (165 mL) was added dropwise to this solution over a period of 0.5 hours. After the dropwise addition, the reaction mixture was slowly warmed to room temperature and stirring was continued for 16 hours. Upon completion of the reaction, the reaction mixture was diluted with 4 M sodium hydroxide solution (400 mL) and subsequently extracted with tert-butyl methyl ether (TBME). All TBME phases were combined, dried with anhydrous magnesium sulfate and finally concentrated under vacuum to give the target product 4-bromo-2-methylpyridine (153). Yield: 14.8 g (92% yield).LC/MS analysis: retention time 0.57 min, mass spectrum (ES+) m/z 172, 174 ([M+H]+).

[1] Patent: WO2008/57497, 2008, A2. Location in patent: Page/Page column 292
[2] Patent: WO2007/89669, 2007, A2. Location in patent: Page/Page column 203-204
[3] Patent: WO2008/57469, 2008, A1. Location in patent: Page/Page column 292
[4] Patent: WO2008/57468, 2008, A1. Location in patent: Page/Page column 292
[5] Patent: WO2004/14913, 2004, A2. Location in patent: Page 81-82