29709-35-1

50-00-0

71257-38-0

General procedure for the synthesis of 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine from 2-(1H-pyrrol-1-yl)ethylamine and formaldehyde: 2-(1H-pyrrol-1-yl)ethylamine (2 g, 18 mmol) was dissolved in 40 mL of ethanol, followed by the addition of 40% aqueous formaldehyde (1.5 mL, 18 mmol) and the slow dropwise addition of 1 mL trifluoroacetic acid. The reaction mixture was heated to 50 °C and maintained for 15 minutes, then cooled to room temperature and stirred continuously for 12 hours. Upon completion of the reaction, the solvent was removed by concentration under reduced pressure, diluted by adding 50 mL of ethyl acetate, and the organic phase was washed with 50 mL of saturated sodium bicarbonate solution, followed by drying with anhydrous sodium sulfate and filtration. Finally, the filtrate was concentrated by decompression to afford 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine (1.60 g, 72.7% yield) as a light yellow oil.