Potassium Carbonate → Tert-butyl 4-(5-isopentyl-[1,2,4]triazolo[4,3-a]pyrazin-8-yl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A 50 mL round bottom flask was charged with tert-butyl 4-(5-bromo-[1,2,4]triazolo[4,3-a]pyrazin-8-yl)piperazine-1-carboxylate (1.0 g, 2.61 mmol), isopentylboronic acid (484 mg, 4.18 mmol), Pd(PPh3)4 (300 mg, 0.261 mmol), 2 M aqueous K2CO3 (2.6 mL, 5.2 mmol) and toluene (15 mL) under N2. The resulting mixture was heated under N2 at 100° C. overnight. Work-up: the reaction mixture was filtered. The filter cake was washed with EtOAc (10 mL) and the filtrate was extracted with more EtOAc (10 mL×3). The combined organic solutions were washed with brine, dried over anhydrous Na2SO4, and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel with 2% methanol in dichloromethane, to afford 0.43 g (44%) of tert-butyl 4-(5-isopentyl-[1,2,4]triazolo[4,3-a]pyrazin-8-yl)piperazine-1-carboxylate as a yellow solid. MS m/z: 375 (M+H+).

Provenance & Evidence