ChemicalBook CAS DataBase List 2-BROMO-5-METHOXYPYRIDINE

2-BROMO-5-METHOXYPYRIDINE synthesis

5synthesis methods

Product Name:2-BROMO-5-METHOXYPYRIDINE
CAS Number:105170-27-2
Molecular formula:C6H6BrNO
Molecular Weight:188.02

10167-97-2

105170-27-2

General procedure for the synthesis of 2-bromo-5-methoxypyridine from 2-amino-5-methoxypyridine: (a) 2-Amino-5-methoxypyridine (14.8 g, prepared according to the method described by JG Lombardino, J. Med. Chem., 1981, 24, 39) was dissolved in 60% hydrobromic acid (150 ml) and cooled to -10°C. Bromine (47.47 g) was added slowly and dropwise with stirring. A solution of sodium nitrite (20.53 g) in water (40 ml) was added dropwise to the resulting yellow suspension, keeping the reaction temperature below -5°C. The mixture was stirred to room temperature and cooled to 0°C after 0.5 h. A solution of sodium hydroxide (120 g) in water (100 ml) was added slowly. The mixture was fully extracted with ether, the ether extracts were combined and dried with anhydrous sodium sulfate, followed by evaporation of the solvent. The residue was purified by column chromatography on silica gel (150 g), using dichloromethane as eluent to give a yellow oil (14.1 g, 63% yield). This product was combined with a smaller batch (3.4 g) and purified by distillation under reduced pressure to give finally 2-bromo-5-methoxypyridine (16.4 g) with a boiling point of 76°C-78°C/0.6 torr.

10167-97-2 Synthesis

10167-97-2
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$18.00/1g

105170-27-2
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$8.00/1g

Yield:105170-27-2 63%

Reaction Conditions:

with sodium hydroxide;bromine;sodium nitrite in water;hydrogen bromide

Steps:

36.a L-3,5-Diiodo-3'-(5-hydroxy-2-pyridylmethyl)-thyronine
(a) 2-Amino-5-methoxypyridine (14.8 g, prepared by the method of J.G. Lombardino, J. Med. Chem., 1981, 24, 39) was dissolved in 60% hydrobromic acid (150 ml) and to the cooled (-10°) stirred solution bromine (47.47 g) was added dropwise. To the resulting yellow suspension was added, dropwise, sodium nitrite (20.53 g) in water (40 ml), keeping the temperature below -5°. The mixture was stirred to room temperature, and after 0.5 hour cooled to 0°, and a solution of sodium hydroxide (120 g) in water (100 ml) was slowly added. The mixture was thoroughly extracted with ether, the combined ether extracts dried with anhydrous sodium sulphate, and evaporated. The residue was chromatographed on silica gel (150 g). Elution with dichloromethane gave a yellow oil (14.1 g, 63%) which was combined with a smaller batch (3.4 g) and distilled under reduced pressure to give 2-bromo-5-methoxypyridine (16.4 g). b.p. 76°-78°/0.6 torr.

References:

Smith Kline & French Laboratories Ltd. US4766121, 1988, A

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55717-45-8 Synthesis