ChemicalBook CAS DataBase List 3-Bromo-6-chloro-2-methylpyridine

3-Bromo-6-chloro-2-methylpyridine synthesis

4synthesis methods

Product Name:3-Bromo-6-chloro-2-methylpyridine
CAS Number:132606-40-7
Molecular formula:C6H5BrClN
Molecular Weight:206.47

42753-71-9 Synthesis

42753-71-9
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132606-40-7
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Yield: 70%

Reaction Conditions:

Stage #1:5-bromo-6-methyl-pyridin-2-ylamine with hydrogenchloride;pyridine hydrochloride;copper(l) chloride;sodium nitrite in dichloromethane;water at 0 - 20; for 1.5 h;
Stage #2: with sodium hydrogencarbonate in dichloromethane;water

Steps:

To a 2L 3-neck RBF was added CH₂Cl₂ (900 mL) followed by 2-amino-6-methyl- 5-bromopyridine (74.23 g, 0.39 mol), pyridine-HCl (139 g, 1.2 mol), NaNO₂ (83.26 g, 1.2 mol) and CuCl (3.76 g, 5% w/w to starting material). The mixture was cooled to 0-10 ⁰C in an ice- water bath and cone. HCl (4.5 mL, 6% v/w to starting material) was added dropwise and the mixture stirred at 0-10 ⁰C for 30 min. The cooling bath was removed and the mixture was stirred at rt for Ih. The reaction mixture was quenched with saturated aqueous NaHCO₃ (400 mL), the layers separated and the aqueous layer was extracted with CH₂Cl₂ (100 mL). The combined organic layers were concentrated to dryness and hexanes (750 mL) was added to the residue under stirring. The solid was filtered and washed with hexane and the filtrate was concentrated to dryness to afford pure product as a light yellow crystalline solid (61 g, 70%).

References:

ANORMED INC. WO2007/22371, 2007, A2 Location in patent:Page/Page column 49