Propargyl bromide → 3-(Benzhydrylidene-amino)-1-methyl-3-prop-2-ynyl-pyrrolidin-2-one

Participants

Reaction Steps

Potassium tert-butoxide 1.7M in THF (32.8 mL, 55.76 mmol) was added dropwise over a period of 80 minutes (by syringe pump) to a solution of the 3-(benzhydrylidene-amino)-1-methyl-pyrrolidin-2-one (14.11 g, 50.692 mmol) (which may be prepared as described in Description 1) and propargyl bromide (6.78 mL, 60.83 mmol) in THF (250 mL) at 0° C. under nitrogen. The reaction was stirred for 2 hours. Additional KOtBu (5 ml) was added dropwise and stirring was continued for 15 mins. The reaction was quenched by the addition of satd. aq. NaHCO3 and diluted with EtOAc. The phases were separated, the organic layer was dried (Na2SO4) and the solvent evaporated to afford a crude brown oil which solidified on standing. This waxy-solid was suspended in IPA (approx. 30 ml) and stirred for 1 hr. The solid was filtered off, washed with a little IPA to afford 3-(benzhydrylidene-amino)-1-methyl-3-prop-2-ynyl-pyrrolidin-2-one (D2) as a light brown solid (6.26 g);

Provenance & Evidence