Formaldehyde → 1,2,3,4-Tetrahydropyrrolo(1,2-a)pyrazine

Participants

Reaction Conditions

Reaction Steps

2-Pyrrol-1-yl-ethanamine 2b (2 g, 18 mmol) was dissolved in 40 mL of ethanol, followed by addition of formaldehyde solution (40%, 1.5 mL, 18 mmol) and a slow dropwise addition of 1 mL of trifluoroacetic acid. The reaction mixture was heated to 50° C. for 15 minutes, then cooled to room temperature and stirred for 12 hours. The reaction mixture was concentrated under reduced pressure, added with 50 mL of ethyl acetate, washed with saturated sodium bicarbonate solution (50 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure to obtain 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine 2c (1.60 g, yield 72.7%) as a light yellow oil.

Provenance & Evidence