N-methyl-2-pyrrolidone → HCID 67026912, compound

Participants

Reaction Conditions

Reaction Steps

5-Chloro-6-methyl-nicotinic acid tert.-butyl ester (3.09 g, 13.5 mmol), Fe(acac)3 (719 mg, 2.04 mmol) and NMP (1.95 mL, 20 mmol) are dissolved in THF (3M, 500 mL) and cooled at −78° C. A solution of isobutylmagnesium bromide in THF (2M, 13.6 mmol) is slowly added at −75° C. The brown solution turns turbid and yellow. Stirring is continued for 1 h at −75° C. before it is slowly warmed to rt. The reaction is incomplete, further Fe(acac)3 (719 mg, 2.04 mmol) is added and the mixture is cooled again at −70° C. Further methylmagnesium bromide in THF (2M, 13.6 mmol) is slowly added at −70° C. The dark green mixture is slowly warmed to rt and stirred for 15 h. The mixture is carefully quenched with 0.7N aq. HCl (150 mL). The mixture is extracted with EA (6×60 mL). The combined org. extracts are dried over Na2SO4, filtered and evaporated. The residue is purified by reversed phase MPLC to give 6-methyl-5-isobutyl-nicotinic acid tert.-butyl ester as black oil (0.50 g); LC-MS: tR=0.84 min, [M+1]+=250.14.

Provenance & Evidence