485841-52-9

General procedure for the synthesis of (S)-1,2-dimethylpiperazine from the compound (CAS:1152110-42-3): tert-butyl (S)-3,4-dimethylpiperazine-1-carboxylate (intermediate R27; 3.9335 g, 18.354 mmol) was dissolved in dichloromethane (DCM; 2.0 mL) and trifluoroacetic acid (TFA; 1.5 mL , 19.5 mmol). The reaction mixture was stirred at room temperature overnight. Upon completion of the reaction, the mixture was concentrated under vacuum to remove the solvent. The residue was diluted with a 4:1 solvent mixture of DCM:isopropanol (iPrOH) and extracted with saturated aqueous sodium bicarbonate (NaHCO3). The aqueous phase was back-extracted with a 4:1 solvent mixture of DCM:iPrOH. All organic phases were combined, dried over anhydrous sodium sulfate (Na2SO4), filtered and concentrated under vacuum to afford the target product (S)-1,2-dimethylpiperazine (2.0 g, 95% yield). Mass spectrum (APCI) m/z = 115.3 (M + H).

[1] Patent: WO2018/71454, 2018, A1. Location in patent: Paragraph 001423; 001424; 001425
[2] Journal of Medicinal Chemistry, 2012, vol. 55, # 20, p. 8721 - 8734,14
[3] Journal of Medicinal Chemistry, 2012, vol. 55, # 20, p. 8721 - 8734