Triethylamine → 1-(2-Nitro-6,7-dihydropyrazolo[1,5-a]pyrazin-5(4H)-yl)propan-1-one

Participants

Reaction Steps

To a solution of 2-nitro-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine 209a (200 mg, 1.19 mmol) in dichloromethane (8 mL) was added Et3N (240 mg, 2.38 mmol). After stirring for 5 minutes, a solution of propionyl chloride (121 mg, 1.31 mmol) in dichloromethane (2 mL) was added and the reaction mixture was stirred at room temperature for 1 h. Analysis of the reaction mixture by LCMS showed complete conversion to the desired product. The mixture was washed with water and brine, dried over Na2SO4, and filtered. The filtrate was concentrated under reduced pressure to afford 265a (260 mg, 98%) as white solid, which was used in the next step without further purification. MS-ESI: [M+H]+ 225.0

Provenance & Evidence