Tetrahydrofuran → Tert-butyl 4-(5-isobutyl-[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 (0.5 g, 1.3 mmol), Pd(PPh3)2Cl2 (140.3 mg, 0.20 mmol) and toluene (8 mL) under N2. To the above was injected a 2 M solution of isobutylzinc(II) bromide in THF (10.4 mL, 5.2 mmol). The resulting mixture was stirred under N2 at 20° C. for 0.5 h then 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 0.30 g (64%) of tert-butyl 4-(5-isobutyl-[1,2,4]triazolo[4,3-a]pyrazin-8-yl)piperazine-1-carboxylate as a yellow solid. MS m/z: 361 (M+H+).

Provenance & Evidence