ChemicalBook CAS DataBase List 3-Bromo-4-methylpyridine

3-Bromo-4-methylpyridine synthesis

7synthesis methods

Product Name:3-Bromo-4-methylpyridine
CAS Number:3430-22-6
Molecular formula:C6H6BrN
Molecular Weight:172.02

3430-27-1 Synthesis

3430-27-1
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3430-22-6
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Yield:3430-22-6 95%

Reaction Conditions:

Stage #1: 3-amino-4-methylpyridinewith hydrogen bromide;bromine at -5;
Stage #2: with sodium nitrite in water at 0;
Stage #3: with sodium hydroxide in water at 0 - 20; pH=9; for 0.5 h;

Steps:

1.2; 2.2; 3.2 Preparation of 4-methyl-3-bromopyridine

2-Methyl-4-aminopyridine (10.8 g, 0.1 mol) was added to 48% HBr (46 ml, 0.4 mol) under cooling in an ice salt bath. After the addition was completed, it was cooled to -5 ° C and slowly added dropwise. Bromine (15ml, 0.3mol), 30-35min addition, then add 40g of 40% sodium nitrite solution below 0 ° C, add in 1-1.1h, continue to stir at 0 ° C for 30min, then Add 50% sodium hydroxide solution slowly below 20 °C to adjust the pH of the solution to 9, the reaction solution is extracted with ethyl acetate, the substrate is dried over anhydrous sodium sulfate, filtered with suction and concentrated to give 4-methyl-3-bromopyridine, the molar yield was 95%.

References:

CN109761891,2019,A Location in patent:Paragraph 0014; 0017; 0019; 0020; 0022; 0023; 0025