3,4-Dihydroxybenzaldehyde
3,4-Dihydroxybenzaldehyde (CAS: 139-85-5), also known as Protocatechualdehyde, is a key organic building block with the molecular formula (HO)2C6H3CHO and a molecular weight of 138.12 g/mol. This aromatic aldehyde, featuring two hydroxyl groups and one aldehyde group on a benzene ring, serves as a versatile intermediate in the synthesis of pharmaceuticals, agrochemicals, and flavour and fragrance compounds. Its specific substitution pattern makes it valuable for targeted chemical transformations.
- IUPAC
- Protocatechualdehyde
- Synonyms
- (HO)2C6H3CHOProtocatechualdehyde

Pharmaceutical Intermediates
3,4-Dihydroxybenzaldehyde is utilised as a starting material or intermediate in the synthesis of various active pharmaceutical ingredients (APIs). Its structure allows for diverse derivatisation to create complex drug molecules.
Agrochemical Synthesis
This compound finds application in the development and production of pesticides, herbicides, and other agrochemicals. Its functional groups enable its incorporation into molecules designed for crop protection.
Flavour and Fragrance Industry
As a precursor to certain flavour and fragrance compounds, 3,4-Dihydroxybenzaldehyde can be chemically modified to produce desirable aroma profiles.
Research and Development
It is widely employed in academic and industrial research labs as a building block for exploring novel organic compounds and synthetic methodologies.
| Molecular weight | 138.12 |
|---|---|
| Linear formula | (HO)2C6H3CHO |
| Grade | purum |
| Melting point | 150-157 °C(lit.) |

Hazard statements
- H315Causes skin irritation
- H319Causes serious eye irritation
- H335May cause respiratory irritation
Precautionary statements
- P261Avoid breathing dust, fume, gas or vapours
- P305IF IN EYES
| Protective equipment | dust mask type N95 (US), Eyeshields, Gloves |
|---|---|
| Water hazard class (WGK, DE) | 3 |
| Hazard codes (EU) | Xi |
| Risk statements (R) | 36/37/38 |
| Safety statements (S) | 26 |
Hazard information is provided for guidance. Always consult the product Safety Data Sheet (SDS), available on request, before handling.
Documentation
Every batch ships with a Certificate of Analysis covering assay, identity and purity; the grade is confirmed against your enquiry. Safety Data Sheets and technical data sheets are available on request.
Supply & logistics
Samples for technical evaluation; bulk MOQ by grade and packaging. In-stock material ships in 7–10 working days, worldwide, with full export documentation.
What is 3,4-Dihydroxybenzaldehyde used for?
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3,4-Dihydroxybenzaldehyde is primarily used as an intermediate in the synthesis of pharmaceuticals, agrochemicals, and flavour and fragrance compounds, as well as in general organic synthesis and research.
What is the CAS number and molecular formula for 3,4-Dihydroxybenzaldehyde?
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The CAS number is 139-85-5 and the molecular formula is (HO)2C6H3CHO.
What grade and purity does Tech Serve Solutions supply?
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Tech Serve Solutions supplies 3,4-Dihydroxybenzaldehyde in 'purum' grade. TSS does not represent this product as USP, BP, EP, or any other pharmacopoeia grade unless explicitly stated.
How should 3,4-Dihydroxybenzaldehyde be handled?
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Handle 3,4-Dihydroxybenzaldehyde with appropriate personal protective equipment including a dust mask type N95 (US), eyeshields, and gloves. Ensure adequate ventilation to avoid inhaling dust. It is classified as causing skin irritation (H315), serious eye irritation (H319), and respiratory irritation (H335).
Is 3,4-Dihydroxybenzaldehyde a controlled substance?
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The provided data does not indicate that 3,4-Dihydroxybenzaldehyde is a controlled substance.
How is 3,4-Dihydroxybenzaldehyde typically packed and shipped?
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Products are packed according to industry standards to ensure safe transport. As a global supplier, Tech Serve Solutions exports chemicals worldwide, adhering to all relevant shipping regulations.
How can I request a sample or quote for 3,4-Dihydroxybenzaldehyde?
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To request a sample or a formal quotation, please contact the Tech Serve Solutions sales team via our website or by telephone, providing your specific requirements.
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