L-Methionine → 3-(2,5-Dimethyl-pyrrol-1-yl)-5-isopropyl-1-methyl-1H-pyrazole

Participants

Reaction Steps

To a solution of 3-(2,5-dimethyl-pyrrol-1-yl)-5-isopropyl-1H-pyrazole (7.7 g, 37.9 mmol) in THF (400 mL) that is purged with nitrogen is added NaH (2.272 g, 56.8 mmol) at 0° C. The mixture is stirred for 10 min in the ice bath then for 10 min at room temperature. Met (4.74 mL, 76 mmol) is added and the mixture is stirred at room temperature for 1 h. At that point the reaction is diluted with DCM and treated with saturated solution of ammonium chloride (10 mL). The mixture is concentrated to dryness and the residue is partitioned in water and DCM. The organic layer is combined, dried over sodium sulfate, concentrated and absorbed onto silica to purify by FCC (0-30% EtOAC/Heptane) to give 5-(2,5-Dimethyl-pyrrol-1-yl)-3-isopropyl-1-methyl-1H-pyrazole (2.4 g, 29%) as the first peak and 3-(2,5-Dimethyl-pyrrol-1-yl)-5-isopropyl-1-methyl-1H-pyrazole (5.24 g, 63%) as the second peak. MS (ESI) m/z 218.3 (m+1).

Provenance & Evidence