Pyrazolidine
Names
Preferred IUPAC name
Pyrazolidine[1]
Other names
1,2-Diazolidine
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
UNII
• InChI=1S/C3H8N2/c1-2-4-5-3-1/h4-5H,1-3H2
Key: USPWKWBDZOARPV-UHFFFAOYSA-N
• InChI=1/C3H8N2/c1-2-4-5-3-1/h4-5H,1-3H2
Key: USPWKWBDZOARPV-UHFFFAOYAM
• C1CNNC1
Properties
C3H8N2
Molar mass 72.10902
Density 1.00 g/cm3 (20 °C)[2]
Melting point 10 to 12[2] °C (50 to 54 °F; 283 to 285 K)
Boiling point 138[2] °C (280 °F; 411 K)
1.477[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Pyrazolidine is a heterocyclic compound. It is a liquid that is stable in air, but it is hygroscopic.[2]

## Preparation

Pyrazolidine can be produced by cyclization of 1,3-dichloropropane or 1,3-dibromopropane with hydrazine:[2]

${\displaystyle \mathrm {Cl{-}(CH_{2})_{3}{-}Cl\ +\ N_{2}H_{4}\ \xrightarrow {\Delta T} \ C_{3}H_{8}N_{2}\ +\ 2HCl} }$
${\displaystyle \mathrm {Br{-}(CH_{2})_{3}{-}Br\ +\ N_{2}H_{4}\ {\xrightarrow {\Delta T))\ C_{3}H_{8}N_{2}\ +\ 2HBr} }$