Triethylamine → Tert-butyl 4-(tetrazolo[1,5-a]pyrazin-8-yl)piperazine-1-carboxylate

Participants

Reaction Steps

A 3 L round bottom flask was charged with 8-chlorotetrazolo[1,5-a]pyrazine (350 g, 2.3 mol), tert-butyl piperazine-1-carboxylate (420 g, 2.3 mol), triethylamine (460 g, 4.5 mol), and EtOH (2 L). The mixture was heated at reflux for 1 h. Work-up: the reaction mixture was concentrated in vacuo. The residue was mixed with saturated aqueous NaHCO3 (1 L) and then extracted with CH2Cl2 (1 L×3). The combined organic layers were dried over anhydrous Na2SO4 and concentrated in vacuo. The residue was further purified by flash column chromatography on silica gel with 8% EtOAc in CH2Cl2 (containing 2% Et3N), to afford 630 g (91%) of the product as a white solid. MS m/z: 306 (M+H+).

Provenance & Evidence