5-BroMo-6-Methoxypyridine-3-carboxylic acid synthesis

Yield:-

Reaction Conditions:

Stage #1: methyl 5-bromo-6-methoxy-pyridine-3-carboxylatewith water;lithium hydroxide in 1,4-dioxane;methanol at 60; for 2 h;Inert atmosphere;
Stage #2: with hydrogenchloride in water;Inert atmosphere;

Steps:

92.1

Step 1 : 5-Bromo-6-methoxy-nicotinic acid5-Bromo-6-methoxy-nicotinic acid methyl ester (W. J. Thompson et al., J. Org. Chem 49 (1984), 5237-5243; 2.00 g, 8.13 mmol) was dissolved in dioxane (40 ml), lithium hydroxide (40 ml of a 1 M solution in water) was added and subsequently sufficient methanol to achieve complete dissolution. The mixture was stirred at 60 °C for 2 h. The methanol was evaporated in vacuo and the remaining mixture was acidified with 2 N hydrochloric acid and extracted with EA. The combined extracts were dried over sodium sulfate, filtered and evaporated to dryness to yield the title compound.1H-NMR: δ = 13.3 (s, 1 H); 8.68 (d, 1 H); 8.35 (d, 1 H); 4.01 (s, 3H)

References:

WO2011/53948,2011,A1 Location in patent:Page/Page column 158