5-Amino-1H-pyrazol-3(2H)-one
Also known as: 3-Amino-3-pyrazolin-5-one, 5-Amino-1,2-dihydro-3H-pyrazol-3-one, 3-Amino-1,2-dihydropyrazol-5-one, 5-Amino-3-hydroxy-1H-pyrazole, 3-Amino-1H-pyrazol-5-ol, 5-Aminopyrazol-3-ol, 5-Amino-3-pyrazolone, 3H-Pyrazol-3-one,5-amino-1,2-dihydro-
5-Amino-1H-pyrazol-3(2H)-one (CAS 28491-52-3) is a compound in the Pharma Intermediates category listed in the Jingsj chemical database. It has the molecular formula C3H5N3O and a molecular weight of 99.091 g/mol. Key properties include a melting point of 204°C, a boiling point of 479.5±25.0 °C at 760 mmHg, a density of 1.6±0.1 g/cm3 and a flash point of 243.8±23.2 °C. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.
- CAS No.
- 28491-52-3
- Jingsj CID
- J-1526548-2
- Molecular Formula
- C3H5N3O
- Molecular Weight
- 99.091 g/mol
- Category
- Pharma Intermediates
- Last updated
- 8/21/2026
No offers for this compound yet.
Request a quotePhysicochemical Properties
| Melting Point | 204°C |
|---|---|
| Boiling Point | 479.5±25.0 °C at 760 mmHg |
| Density | 1.6±0.1 g/cm3 |
| Flash Point | 243.8±23.2 °C |
| Exact Mass | 99.043259 |
| PSA | 74.67000 |
| LogP | -0.22 |
| Vapor Pressure | 0.0±1.2 mmHg at 25°C |
| Refractive Index | 1.741 |
| Storage Conditions | 2-8°C |
Customs & Trade Information
| HS Code | 2933199090 |
|---|---|
| Summary | 2933199090. other compounds containing an unfused pyrazole ring (whether or not hydrogenated) in the structure. VAT:17.0%. Tax rebate rate:13.0%. . MFN tariff:6.5%. General tariff:20.0% |
Frequently Asked Questions
What is the CAS number of 5-Amino-1H-pyrazol-3(2H)-one?
The CAS number of 5-Amino-1H-pyrazol-3(2H)-one is 28491-52-3.
What are the molecular formula and molecular weight of 5-Amino-1H-pyrazol-3(2H)-one?
5-Amino-1H-pyrazol-3(2H)-one has molecular formula C3H5N3O and molecular weight 99.091 g/mol.
What are the upstream and downstream products of 5-Amino-1H-pyrazol-3(2H)-one?
For 5-Amino-1H-pyrazol-3(2H)-one, Upstream Products: Cyanoacetohydrazide, Sodium methoxide, Sodium ethoxide; Downstream Products: 5-Methoxy-1H-pyrazol-3-amine, 3H-Pyrazolo[3,4-b]pyridin-3-one, 1,2-dihydro-4,6-dimethyl-, 5,7-Dimethylpyrazolo[1,5-a]pyrimidin-2-ol.
Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.
Last updated:
How to cite: Jingsj. "5-Amino-1H-pyrazol-3(2H)-one (CAS 28491-52-3)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-1526548-2 (accessed 2026-11-09).
Data for reference only; verify product details with suppliers before purchase.