Cesium carbonate → rac-(4R,5R)-4-[(4-iodo-1H-pyrazol-1-yl)methyl]-1-(4-methoxybenzyl)-5-methylpyrrolidin-2-one

Participants

Reaction Conditions

Reaction Steps

4-Iodo-1H-pyrazole (0.93 g, 4.77 mmol) and cesium carbonate (2.59 g, 7.95 mmol) were added to a solution of [(2R,3S)-1-(4-methoxybenzyl)-2-methyl-5-oxopyrrolidin-3-yl]methyl rac-methanesulfonate (1.3 g, 3.98 mmol) in DMF (26 mL). The mixture was stirred at 90° C. under a nitrogen atmosphere for 3 hours. After cooling to room temperature, the mixture was diluted with water (50 mL) and extracted with ethyl acetate (100 mL×3). The combined organic layers were dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by chromatography on silica gel (ethyl acetate/petroleum ether) to afford rac-(4R,5R)-4-[(4-iodo-1H-pyrazol-1-yl)methyl]-1-(4-methoxybenzyl)-5-methylpyrrolidin-2-one. MS ESI calc'd. for C17H21IN3O2 [M+H]+ 426. found 426. 1H NMR (400 MHz, CDCl3): δ 7.47 (s, 1H), 7.17 (d, J=8.5 Hz, 2H), 6.95 (s, 1H), 6.90 (d, J=8.5 Hz, 2H), 4.99-4.94 (m, 1H), 4.02-3.99 (m, 1H), 3.90-3.85 (m, 1H), 3.85 (s, 3H), 3.82-3.79 (m, 1H), 3.15-3.06 (m, 1H), 2.69-2.63 (m, 1H), 2.58-2.48 (m, 1H), 2.18-2.09 (m, 1H), 1.06 (d, J=6.5 Hz, 3H).

Provenance & Evidence