Benzoyl chloride → 5-benzoyl-N-methyl-N-phenyl-2,3-dihydro-1H-pyrrolizine-1-carboxamide

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Reaction Steps

N-Methyl-N-phenyl-2,3-dihydro-1H-pyrrolizine-1-carboxamide (52 g, 216 mmol), lithium carbonate (24 g, 325 mmol, 1.5 equivalents), and toluene (155 mL) were heated to a reflux temperature of 100° C. to 105° C. Benzoyl chloride (37.5 g, 267 mmol, 1.25 equivalents) was added, and the entire reaction mixture was allowed to reflux for an additional 6 hours to 8 hours. Once the reaction was complete, the mixture was cooled to 70° C. to 80° C., lithium carbonate was filtered off and the filter cake washed with 100 mL warm toluene, and the combined filtrate and washings were seeded with a few crystals of 5-benzoyl-N-methyl-N-phenyl-2,3-dihydro-1H-pyrrolizine-1-carboxamide. Hexane (100 mL) was added to the warm toluene solution to effect crystallization, and the mixture was stirred for 30 minutes; then another 80 mL of hexane was added. The mixture was stirred for 1 hour to 2 hours at room temperature, cooled to 0° C. to 5° C., filtered, washed with hexane (150 mL) and dried under vacuum at 60° C. to 70° C. to yield 5-benzoyl-N-methyl-N-phenyl-2,3-dihydro-1H-pyrrolizine-1-carboxamide (61.7 g, 82.8% yield).

Provenance & Evidence