Water → HCID 87209263, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 6-chloro-4-methyl-2-vinyl-pyridine (1.24 g, 8.06 mmol) in water (50 mL) and acetone (50 mL), KMnO4 (6.53 g, 41.3 mmol) is added. The dark mixture becomes warm (40° C.) and is stirred at rt for 3 h before it is filtered over a sintered glass filter. The solvent of the colourless filtrate is evaporated to give crude 6-chloro-4-methyl-pyridine-2-carboxylic acid potassium salt (3.2 g) as a colourless solid; LC-MS: tR=67 min, [M+1]+=171.99. This material is suspended in ethanol (150 mL) and H2SO4 (2 mL) is added until a clear solution forms. The mixture is heated to 70° C. for 18 h. The mixture is carefully diluted with sat. aq. NaHCO3 solution until a pH of 9 is reached. The mixture is extracted three times with EA. The combined org. extracts are dried over MgSO4, filtered and concentrated. The crude product is purified by CC on silica gel eluting with heptane:EA 3:2 to give ethyl 6-chloro-4-methyl-pyridine-2-carboxylate (500 mg) as a pale yellow oil; LC-MS: tR=0.87 min; [M+1]+=200.04; 1H NMR (CDCl3): δ 1.45 (t, J=7.3 Hz, 3H), 2.45 (s, 3H), 4.48 (q, J=6.8 Hz, 2H), 7.35 (s, 1H), 7.89 (s, 1H).

Provenance & Evidence