Product Overview

4-Amino-2,3-dichlorophenol is a regioisomerically defined dichloroaminophenol building block supplied as an off-white to light brown crystalline powder. It carries an amino group para to a phenolic hydroxyl group, with two adjacent chlorine atoms ortho to the hydroxyl, a substitution pattern that gives the molecule two orthogonally reactive sites and enhanced metabolic and oxidative stability. The 2,3-dichloro arrangement is the specific isomer required for hydroxyanilide fungicide chemistry and cannot be substituted by the 2,4-, 2,5- or 2,6-dichloro isomers.

Key Attributes

Key Highlights

• ISOMER-SPECIFIC: Supplied as the defined 2,3-dichloro regioisomer, the substitution pattern required by hydroxyanilide fungicide routes. Isomeric purity is confirmed by HPLC and NMR on every batch.
• HIGH ASSAY: Not less than 98.0% by HPLC, matching the purity threshold used in the dedicated EU customs tariff line for this substance.
• DUAL REACTIVE SITES: The amino group and the phenolic hydroxyl group react independently, allowing selective derivatization without protecting-group gymnastics in many sequences.
• HALOGEN-DIRECTED CHEMISTRY: Two adjacent chlorine atoms direct regioselective transformation and improve the oxidative and metabolic stability of downstream scaffolds.
• FLEXIBLE ORDER SIZE: Minimum order quantity of 1 kg, with packaging available from 1 kg up to 25 kg to suit process development and pilot-scale campaigns.
• FULL DOCUMENTATION: Each shipment is accompanied by a batch Certificate of Analysis, and Technical Data Sheet and Safety Data Sheet are provided on request.
• PROMPT LEAD TIME: Orders are normally dispatched within 2 weeks of order confirmation.

Product Description

4-Amino-2,3-dichlorophenol (CAS 39183-17-0) is a chlorinated aromatic aminophenol with the molecular formula C6H5Cl2NO and a molecular weight of 178.02 g/mol. Dideu Group supplies this material as a crystalline powder at not less than 98.0% assay by HPLC, intended for use as a synthetic intermediate in agrochemical and pharmaceutical process chemistry.

The value of this compound lies in its substitution pattern rather than in its functional groups alone. The hydroxyl and amino groups occupy para positions to each other, while the two chlorine atoms sit adjacent to one another ortho to the hydroxyl group. This 2,3-dichloro arrangement is what distinguishes it from the more widely catalogued 2,6-dichloro isomer, and routes designed around it are isomer-specific: the wrong regioisomer will not carry the target molecule through subsequent cyclization or acylation steps. For process chemists working on hydroxyanilide-type actives and on chlorinated heteroaromatic scaffolds, isomer identity is therefore the primary specification, ahead of assay.

Aminophenols of this class are prone to oxidative darkening on exposure to air and light, which is why the material is packed in light-blocking packaging and stored refrigerated. Buyers should expect some batch-to-batch variation in colour from off-white through light brown; colour within this range does not by itself indicate a specification failure, and assay by HPLC remains the controlling test.

The minimum order quantity is 1 kg, and standard lead time is within 2 weeks of order confirmation. Shipments move by air or by sea depending on quantity and destination. Payment terms are T/T and L/C. Dideu Group serves customers in global markets.

Applications

Agrochemical Intermediates

This is the principal commercial use of the compound. 4-Amino-2,3-dichlorophenol is the key aromatic starting material for hydroxyanilide fungicides, most notably fenhexamid, which is used against grey mould in grape, berry and stone-fruit production. The amino group is acylated to form the anilide linkage that defines this fungicide class.

Pharmaceutical Intermediates

The compound serves as a building block for chlorinated aromatic scaffolds in active pharmaceutical ingredient development. It is used in the preparation of process impurity reference materials for kinase inhibitor programs, where a structurally exact chlorinated aminophenol is required to qualify the impurity profile of the finished drug substance.

Research and Analytical Chemistry

As a well-characterised, isomerically pure aminophenol, it is used as a reference compound in analytical method development, including chromatographic and mass spectrometric methods for aminophenol residues and transformation products.

Fine Chemical Synthesis

The orthogonal reactivity of the amino and phenolic hydroxyl groups allows selective O-alkylation, N-acylation, diazotization and halogen-directed cross-coupling, making the compound a versatile entry point to functionalised chlorophenols, benzoxazoles and related heterocycles.

Potential Applications

• May be used as an intermediate in the synthesis of halogenated benzoxazole and benzothiazole scaffolds explored in medicinal chemistry programs.
• May serve as a monomer or chain terminator in specialty polycondensation chemistry where chlorine substitution is required for flame performance or oxidative stability.
• Is a candidate starting material for chlorinated azo and oxidation-base colourant chemistry, subject to the applicable product registration and safety assessment in the destination market.

The three items under Potential Applications are inferred from the molecular structure and from the behaviour of closely related chlorinated aminophenols. They are not established commercial uses of this specific isomer and should be validated by the buyer before development work begins.

Specifications

Batch-specific results are reported on the Certificate of Analysis supplied with each shipment. Additional tests, tighter isomer limits and custom specifications can be discussed on request.

Packaging and Shipping

• Store at 2-8 C after receipt; the material darkens more quickly at ambient temperature.
• Keep the container tightly closed and protected from light.
• Keep in a dry, well-ventilated place, in the original packaging until use.
• Reseal opened packages promptly and record the opening date.

Transport: by air or by sea, according to order quantity and destination. Lead time: within 2 weeks of order confirmation. Minimum order quantity: 1 kg.

Company Profile

Dideu Group is a professional supplier of fine chemicals and specialty chemicals, serving customers in global markets with a full range of products from lab-scale reagents to industrial quantities. Our focus is on aromatic intermediates, halogenated building blocks and custom-directed materials for agrochemical, pharmaceutical and advanced materials development. We work to documented specifications, support every batch with analytical data, and align our quality paperwork with the registration requirements of our customers' destination markets. Dideu Group positions itself as a reliable secondary and alternative source, helping buyers reduce single-supplier dependency without compromising on documentation or consistency.

FAQ

1. What is the minimum order quantity?

The minimum order quantity is 1 kg. Larger quantities up to 25 kg per drum and multi-drum shipments can be arranged as required.

2. What is the lead time?

Dideu Group normally dispatches orders within 2 weeks of order confirmation.

3. What packaging options do you offer?

Standard packaging is a light-blocking foil bag with desiccant in 1 kg and 5 kg sizes, and a fibre drum with an inner foil liner in 25 kg. Custom packaging can be discussed for specific handling or logistics requirements.

4. What payment terms do you accept?

We accept T/T and L/C.

5. Do you provide a COA and technical documents?

Yes. Every batch is shipped with a Certificate of Analysis reporting assay and the other released specification items. The Technical Data Sheet and Safety Data Sheet are provided on request.

6. How do you ship the goods?

Shipments move by air or by sea depending on the order quantity and the destination. Cold-chain packing is used where required to keep the material within its recommended storage range in transit.

7. Why does the isomer matter for this product?

Routes built on this compound depend on the chlorine atoms being adjacent at the 2- and 3-positions. The 2,4-, 2,5- and 2,6-dichloro isomers share the same molecular formula and molecular weight, so they cannot be distinguished by mass alone and will not perform the same way in the target synthesis. Dideu Group confirms isomer identity by HPLC and NMR.