1,2,2-trimethylpyrrolidin-3-one

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,2,2-Trimethylpyrrolidin-3-one (1.00 g) was dissolved in cyclohexane (5 mL). Pyrrolidine (1.31 mL) and p-toluenesulfonic acid monohydrate (7.48 mg) were sequentially added thereto, and the mixture was heated under reflux for 3 days, and allowed to cool to room temperature. The resultant mixture was concentrated under reduced pressure to thereby give a crude product of 1,2,2-trimethyl-3-(pyrrolidine-1-yl)-2,5-dihydro-1H-pyrrole (972 mg). To the product dissolved in dimethylformamide (10 mL), formamidine disulfide hydrochloride (1.20 g) was added, followed by stirring at room temperature for 4 days. The resultant mixture was concentrated under reduced pressure. Methanol (50 mL) and sodium carbonate anhydrate (20 g) were added to the residue, and the resultant mixture was stirred at room temperature for 1 hour. The insoluble material was removed through filtration, followed by washing with methanol. The filtrate was concentrated under reduced pressure. The residue was purified by silica gel chromatography (methanol methylene chloride=1:99→1:9), to thereby give the title compound (580 mg). the mixture was heated under reflux for 3 days The resultant mixture was concentrated under reduced pressure