Potassium Carbonate → 4-Methyl-5-(2-methyl-propenyl)-pyridine-2-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-bromo-4-methyl-pyridine-2-carboxylic acid ethyl ester (4.03 g, 16.5 mmol) in DME (43 mL), 2,4,6-tri-(2-methyl-propenyl)-cycloboroxane pyridine complex (5.36 g, 16.5 mmol) followed by 2 N aq. K2CO3-solution (16 mL) is added. The mixture is degassed and put under argon before Pd(PPh3)4 (343 mg, 0.297 mmol) is added. The mixture is stirred at 80° C. for 6 h before it is cooled to rt, diluted with diethyl ether (50 mL), washed with sat. aq. NaHCO3-solution (3×30 mL), dried over MgSO4, filtered and concentrated. The crude product is purified by CC on silica gel eluting with heptane:EA 7:3 to give 4-methyl-5-(2-methyl-propenyl)-pyridine-2-carboxylic acid ethyl ester (1.33 g) as a yellow oil; LC-MS: tR=0.87 min, [M+1]+=220.08.

Provenance & Evidence