First the treatment of dichloroethane with ammonia. Second the nickel, cobalt or platinum catalyzed reaction of EDA. Third, the ZnCl, H3PO4 or Al2O3 catalyzed reaction of ethanolamine.

DOI: 10.1021/ja02242a010

Nitration (NaNO2/HCl) followed by reduction (Zn/HCl) of priperzine gives 1-amino piperzine.

Look at Scheme 1 in the attachment PDF.

Ref. Journal of Medicinal Chemistry, 2010, 53, 2882

Procedure:

Step 1. Preparation of N-nitrosopiperazine: Piperazine 0.86 g (10 mmol) in 6N HCl (6 mL) was cooled to -10
C and a solution of NaNO2 (0.69 g, 10 mmol) in H2O (12 mL) was added slowly over 1 h. At a temperature below 0 oC, the pH was adjusted to 10 using NaOH, and then the mixture was extracted using chloroform, dried over Na2SO4, and the solvent removed by evaporation. The crude product was purified by column chromatography using silica gel and 8% MeOH/CH2Cl2 as the mobile phase. The product was a yellow oil, and the yield was 72%.

Step 2. Preparation of N-aminopiperazine:

N-Nitrosopiperazine 230 mg (2 mmol) was dissolved in 2 mL of THF and was then added slowly to a suspension of LiAlH4 (216 mg, 6 mmol) in 10 mL of THF under N2 at 0 oC. The mixture was stirred for 5 min and then heated to reflux for 3 h. The cooled reaction mixture was quenched by MeOH until no further gas evolved, concentrated in vacuo, and filtered. The resulting filter cake was washed with MeOH, and the combined filtrate was evaporated to dryness, yielding crude N-aminopiperazine as a solid. The crude product obtained can be purified by column chromatography.

Synthesis of 1-amino piperazine by reacting (NaNO2/HCl) and followed by reduction Fe or Sn / HCl to give the product .

Dear Sir, the following paper will help you.

https://link.springer.com/content/pdf/10.1007/s10593-005-0097-4.pdf