20327-23-5

1-cyclopropylpiperazine is a piperazine derivative known in the literature by synonyms such as N-cyclopropylpiperazine and 4-cyclopropylpiperazine. It has been used in the preparation of some tri- and tetrasubstituted ureas with histamine H3 antagonist receptor activity, 3-amido-4- anilinoquinolines series as CSF-1R kinase inhibitors, for the synthesis of cyclopropyl amines as modulators of the histamine H3 receptor, sulfonamide compounds as cysteine protease inhibitors, N-oxides as antibacterial agents and in the treatment of the disease caused by helicobacter infection[1].

Tert-butyl 4-cyclopropylpiperazine-1-carboxylate (0.792 g, 3.50 mmol) was used as a raw material, which was dissolved in a 1,4-dioxane solution (4.37 mL, 17.50 mmol) in 4 M HCl. The reaction mixture was stirred at room temperature for 3 hours under nitrogen protection. Upon completion of the reaction, the mixture was filtered and washed with ether to afford the crude product 1-cyclopropylpiperazine (0.659 g) as a white solid. Subsequently, the crude product was purified by ion exchange chromatography through SCX column. The target compound 1-cyclopropylpiperazine was eluted from the column using 3.5 M NH3/MeOH solution, and the pure grades were collected and evaporated to dryness to give the final 1-cyclopropylpiperazine (0.264 g, 59.7% yield) as a yellow oil. The structure of the product was confirmed by 1H NMR (399.9 MHz, DMSO-d6) with chemical shifts δ 0.25-0.30 (2H, m), 0.35-0.40 (2H, m), 1.54-1.60 (1H, m), 2.43 (4H, t), 2.60-2.65 (4H, t), 3.30 (1H, s).

[1] G. Ke?an. “DFT, FT-Raman, and FT-IR investigations of 1-cyclopropylpiperazine.” Journal of Structural Chemistry 54 6 (2014): 1044–1054.