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CAS 99-50-3

CAS 99-50-3 matches 0 EU annex records across Annex II–VI of Regulation 1223/2009.

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Chemical identity and properties

PubChem 2D chemical structure for CAS 99-50-3
CAS 99-50-3PubChem CID 72

Protocatechuic Acid

3,4-dihydroxybenzoic acid is a dihydroxybenzoic acid in which the hydroxy groups are located at positions 3 and 4. It has a role as an EC 1.14.11.2 (procollagen-proline dioxygenase) inhibitor, an antineoplastic agent, a plant metabolite, a human xenobiotic metabolite and an EC 1.1.1.25 (shikimate dehydrogenase) inhibitor. It is a dihydroxybenzoic acid and a member of catechols. It is functionally related to a benzoic acid. It is a conjugate acid of a 3,4-dihydroxybenzoate. — ChEBI

IUPAC name
3,4-dihydroxybenzoic acid
Molecular formula
C7H6O4
Molecular weight
154.12 g/mol
Exact mass
154.02660867 Da
XLogP3
1.1
Topological polar surface area
77.8 Ų
Hydrogen-bond donors
3
Hydrogen-bond acceptors
4
Covalent units
1
Defined stereocentres
0

Also known as

4-Carboxy-1,2-dihydroxybenzeneProtocatehuic acid4,5-Dihydroxybenzoic acid36R5QJ8L4BNSC-16631FEMA NO. 4430CHEBI:36062RefChem:25857
16 more reported names
202-760-0protocatechuateBenzoic acid, 3,4-dihydroxy-3,4-Dihydroxybenzoicacid3,4-Dihydroxy Benzoic AcidprotocatechuicacidCarbohydroquinonic acidCCRIS 62913,4-dihydroxy-benzoic acidEINECS 202-760-0NSC 16631Catechol-4-carboxylic AcidBRN 14488411ykp3, 4-Dihydroxybenzoic acidUNII-36R5QJ8L4B
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External database identifiers

Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Records for CAS 99-50-3

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How CAS 99-50-3 is used on this site

CAS 99-50-3 is the Chemical Abstracts Service identifier used to pin this page to a specific substance. In the current dataset, 0 EU annex records share 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 99-50-3 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.