3-BROMO-4,5-DIMETHYLPYRIDINE Chemical Properties

Melting point:

33-34 °C

Boiling point:

38 °C(Press: 40 Torr)

Density 

1.415±0.06 g/cm3(Predicted)

storage temp. 

Sealed in dry,Room Temperature

form 

solid

pka

3.82±0.28(Predicted)

color 

White to off-white

Safety Information

HS Code 

2933399990

3-BROMO-4,5-DIMETHYLPYRIDINE Usage And Synthesis

Synthesis

Under nitrogen protection and room temperature, 3,4-dimethylpyridine (5.0 g, 46.6 mmol) was dissolved in concentrated sulfuric acid (50.0 mL). Subsequently, N-bromosuccinimide (9.31 g, 51.32 mmol) was added in batches. The reaction mixture was heated to 60 °C and stirred for 18 hours. After completion of the reaction, the mixture was cooled to room temperature, slowly poured into ice-cold water and the pH was adjusted to alkaline with 10% sodium hydroxide solution. The aqueous phase was extracted with ethyl acetate (3 x 50 mL). The organic phases were combined, washed with saturated saline, dried over anhydrous sodium sulfate and concentrated under reduced pressure to give the crude product. The crude product was purified by silica gel column chromatography (100-200 mesh) to afford 3,4-dimethyl-5-bromopyridine (0.8 g, 9.3% yield) using 5% ethyl acetate in hexane solution as eluent. Mass spectrum (ESI) m/z: 186.0 [M(79Br)+H]+, 188.0 [M(81Br)+H]+; nuclear magnetic resonance hydrogen spectrum (1H NMR, CDCl3): δ 2.31 (s, 3H), 2.36 (s, 3H), 8.23 (s, 1H), 8.51 (s, 1H).

References

[1] Tetrahedron, 1998, vol. 54, # 10, p. 2275 - 2280
[2] Patent: WO2016/21742, 2016, A1. Location in patent: Paragraph 0280; 0281
[3] Patent: WO2007/14913, 2007, A1. Location in patent: Page/Page column 99-100
[4] Patent: WO2007/45588, 2007, A1. Location in patent: Page/Page column 117
[5] Patent: WO2012/148808, 2012, A1. Location in patent: Page/Page column 47