CAS 1 record

CAS 21616-59-1

CAS 21616-59-1 matches 1 EU annex record across Annex II–VI of Regulation 1223/2009.

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Chemical identity and properties

PubChem 2D chemical structure for CAS 21616-59-1

CAS 21616-59-1PubChem CID 13525020

1-Methyl-1H-pyrazole-4,5-diamine dihydrochloride

IUPAC name: 1-methylpyrazole-4,5-diamine;dihydrochloride

Molecular formula: C4H10Cl2N4
Molecular weight: 185.05 g/mol
Exact mass: 184.0282517 Da
Topological polar surface area: 69.9 Å²
Hydrogen-bond donors: 4
Hydrogen-bond acceptors: 3
Covalent units: 3
Defined stereocentres: 0

Also known as

2-methylpyrazole-3,4-diamine;dihydrochloride1-METHYL-1H-PYRAZOLE-4,5-DIAMINE 2HCL03FK8ORW3O4,5-Diamino-1-methylpyrazole hydrochloride4,5-Diamino-1-methylpyrazole dihydrochloride4,5-Diamino-1-methyl-1H-pyrazole dihydrochloride4,5-DIAMINO-1-METHYLPYRAZOLE HCLPyrazole, 4,5-diamino-1-methyl-, dihydrochloride

6 more reported names

1H-Pyrazole-4,5-diamine, 1-methyl-, dihydrochloride1H-Pyrazole-4,5-diamine, 1-methyl-, hydrochloride (1:2)UNII-03FK8ORW3O4,5-Diamino-1-methylpyrazole HCl [INCI]DB-1912071-Methyl-1H-pyrazole-4,5-diaminedihydrochloride

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External database identifiers

EPA DTXSID:DTXSID201371781

Retrieved from NIH PubChem on 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Records for CAS 21616-59-1

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How CAS 21616-59-1 is used on this site

CAS 21616-59-1 is the Chemical Abstracts Service identifier used to pin this page to a specific substance. In the current dataset, 1 EU annex record shares this identifier, which helps you cross-check whether the same substance appears under one regulatory context or several.

Use this page when a supplier specification, SDS or raw-material dossier gives you CAS 21616-59-1 and you need to see every linked Annex II–VI record in one place. The entry cards above are the quickest route to concentration limits, warnings, annex placement and product-type conditions.