Acetic Acid → 2-(2,5-Dimethyl-1H-pyrrol-1-yl)-4,5-dimethyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine

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Reaction Steps

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer was charged with 287g (1.54 g, 1.0 eq., 6.70 mmol), formaldehyde (37% in water) (1.09 g, 2.0 eq., 13.4 mmol), NaBH3CN (2.11 g, 5.0 eq., 33.5 mmol), HOAc (3 mL), and methanol (30 mL). The mixture was stirred at room temperature for 1 h and concentrated under reduced pressure. The residue was partitioned between water (50 mL) and dichloromethane (50 mL). The water phase was extracted with dichloromethane (3×50 mL). The combined organic layer was concentrated under reduced pressure to afford crude 287h, which was used in the next step without further purification. MS-ESI: [M+H]+ 245.0

Provenance & Evidence