Potassium Carbonate → 2-(2-Methylpropenyl)-6-vinylisonicotinic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

To a solution of 2,6-dichloro-isonicotinic acid tert.-butyl ester (500 mg, 2.02 mmol), and 2,4,6-trivinylcyclotriboroxane pyridine complex (170 mg, 0.706 mmol) in DME (12 mL), a solution of 2 M aq. K2CO3 (3 mL) followed by Pd(PPh3)4 (30 mg, 0.041 mmol) and triphenylphosphine (50 mg, 0.187 mmol) is added. The mixture is stirred at 45° C. for 15 h. 2,4,6-Tri-(2-methyl-propenyl)-cycloboroxane pyridine complex (594 mg, 1.83 mmol) is then added to the mixture and stirring is continued at 100° C. for 15 h. The mixture is cooled to rt, diluted with 1 N aq. NaOH solution and extracted twice with diethyl ether. The org. extracts are washed with 1 N aq. NaOH solution (2×30 mL), and brine, dried over Na2SO4, filtered and evaporated. The remaining residue is purified by CC on silica gel eluting with heptane:EA 5:1 to give 2-(2-methyl-propenyl)-6-vinyl-isonicotinic acid tert-butyl ester (780 mg) as a colourless oil containing 2,6-di-(2-methyl-propenyl)-isonicotinic acid tert.-butyl ester as impurity; LC-MS: tR=1.01 min, [M+1]+=260.14.

Provenance & Evidence