Hydrochloric Acid → 8-(piperazin-1-yl)-5-(thiophen-2-yl)tetrazolo[1,5-a]pyrazine HCl salt

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Reaction Steps

A 1 L round bottom flask was charged with tert-butyl 4-(5-(thiophen-2-yl)tetrazolo[1,5-a]pyrazin-8-yl)piperazine-1-carboxylate (210 g, 0.54 mol) and THF (400 mL). To this solution was added concentrated HCl (40 mL) dropwise in an ice-water bath. The resulting solution was stirred at reflux for 0.5 h. Reaction progress was monitored by TLC (MeOH/CH2Cl2=1:10). Work-up: the resulting crystalline solid was collected by filtration, washed with EtOH (200 mL), and dried to afford 139 g (79%) of the product as a yellow solid. MS m/z: 288 (M+H+).

Provenance & Evidence