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 (3 M, 500 mL) and cooled at −78° C. A solution of isobutylmagnesium bromide in THF (2 M, 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 (2 M, 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 0.7 N 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