Synthesis
General procedure for the synthesis of tert-butyl 4-aminopiperazine-1-carboxylate from tert-butyl 4-nitroso piperazine-1-carboxylate: At room temperature, the compound (730 mg) obtained in step (1) was dissolved in methanol (10 mL) and zinc powder (1.1 g) was added. Acetic acid (10 mL) was added slowly and dropwise under cooling in an ice bath. The reaction mixture was stirred at room temperature for 2 hours. Upon completion of the reaction, the mixture was filtered and the filtrate was alkalized by adding aqueous sodium bicarbonate to the filtrate. After alkalinization, the mixture was extracted with chloroform. The organic layers were combined, dried with anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure to give tert-butyl 4-aminopiperazine-1-carboxylate (730 mg, yield: 100%) as a light yellow oil.
References
[1] Patent: WO2007/46550, 2007, A1. Location in patent: Page/Page column 120
[2] Patent: WO2006/20561, 2006, A2. Location in patent: Page/Page column 61
[3] European Journal of Medicinal Chemistry, 2018, vol. 158, p. 247 - 258
