Para Anisidine
Para Anisidine — p-anisidine or 4-methoxyaniline — is a solid, electron-rich aniline used across azo and triphenylmethane dye, pigment and pharmaceutical intermediate chemistry, and is the reagent behind the Anisidine Value (AV) test, the standard method for measuring secondary oxidation products in fats and oils.
Chelora Chemicals supplies p-anisidine to dye and pigment manufacturers, pharmaceutical intermediate producers and analytical laboratories worldwide, in bags, drums and container quantities, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 104-94-9
- IUPAC name
- 4-Methoxyaniline
- Molecular formula
- C7H9NO
- Molecular weight
- 123.15 g/mol
- EC / EINECS
- 203-254-2
- UN Number
- 2431
- SMILES
- COc1ccc(N)cc1
- HS Code
- 2922 29*
* Confirm the exact HS heading with your customs broker — classification of amino-ether compounds varies between destination tariffs.
What Para Anisidine is used for
Para Anisidine is aniline carrying a methoxy group para to the amino group. Like the ortho isomer, the methoxy substituent is a strong electron donor, which activates the ring for diazotisation and coupling and gives brighter, deeper azo chromophores than the equivalent methyl- or chloro-substituted anilines. It also condenses readily with aldehydes to form Schiff bases — the reaction basis of the Anisidine Value (AV) test, a globally used method for quantifying secondary lipid oxidation products (unsaturated aldehydes) in edible oils and fats.
In practice p-anisidine is a captive intermediate across dye, pigment and pharmaceutical chemistry, and a standing reagent in oxidative-stability testing laboratories worldwide.
Why the isomer matters
The three anisidine isomers behave differently, and their hazard profiles are not interchangeable:
- 4-Methoxyaniline / para anisidine (CAS 104-94-9) — this product. Methoxy para to the amine. A solid, and the most acutely toxic of the three anisidines by GHS classification.
- 2-Methoxyaniline / ortho anisidine (CAS 90-04-0) — the ortho isomer, a liquid, IARC Group 2B, and the dominant isomer in high-performance pigment manufacture. See our ortho anisidine page.
- 3-Methoxyaniline / meta anisidine (CAS 536-90-3) — the meta isomer, a liquid used across a narrower set of dye and fine-chemical routes.
If your purchase order simply says "anisidine", quote us the CAS number and we will confirm the correct material before the order is placed. We supply related toluidines, chloroanilines and phenylenediamines across our full product catalogue.
Appearance and handling character
p-Anisidine ships as a light tan to reddish-brown crystalline solid melting around 57 °C. It is sparingly soluble in water and dissolves readily in ethanol, ether and benzene. It is sensitive to heat, light and moisture, and darkens progressively in storage. Read the safety section carefully before planning any handling: p-anisidine is classified as fatal by all three exposure routes — a materially more severe acute toxicity category than most other anilines on our range — and that should shape your controls from the outset.
| Parameter | Typical value |
|---|---|
| Appearance | Light tan to reddish-brown crystals |
| Assay (GC) | 99.0% min |
| Moisture (KF) | 0.3% max |
| Melting range | 55 – 59 °C |
| Isomeric & related impurities | 1.0% max |
| Colour (molten, APHA) | Reported per batch |
Important: the figures above are indicative of commercial grade material and are offered for planning only. The batch certificate of analysis is the governing document. If your process demands a tighter assay or a specific colour ceiling, send us the specification and we will quote against it rather than against a generic grade.
| Property | Value |
|---|---|
| Physical state | Crystalline solid at ambient |
| Melting point | ≈ 56 – 59 °C |
| Boiling point | ≈ 243 °C @ 760 mmHg |
| Flash point | ≈ 122 °C |
| Relative density | ≈ 1.07 (molten) |
| Water solubility | Sparingly soluble |
| Organic solubility | Freely soluble in ethanol, ether & benzene |
| Odour | Amine-like |
Physical constants compiled from public reference data for CAS 104-94-9 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
p-Anisidine's volume is spread across colour chemistry, pharma synthesis and a distinctive analytical-testing outlet.
Azo & triphenylmethane dyes
Diazotised p-anisidine couples onto naphthol and pyrazolone components to build azo dyes and pigments, and serves as an intermediate in triphenylmethane dye chemistry — the electron-rich ring gives clean, deep shades.
- Diazo component in azo dye/pigment synthesis
- Shade depends directly on purity and colour ceiling
- See our full aniline intermediate range
Anisidine Value (AV) testing
p-Anisidine reacts with the aldehyde products of lipid oxidation to give a coloured complex, the basis of the AV test used across the edible oil, food and cosmetics industries to track secondary oxidation.
- Reagent-grade purity available
- Widely used in QC and R&D laboratories
- Small-pack quantities in stock
Pharmaceutical intermediates
p-Anisidine is used in the synthesis of several pharmaceutical actives and precursors, including guaiacol-related expectorant chemistry, through amide formation and N-arylation reactions.
- Amide and ether-linked API intermediate chemistry
- Heterocyclic ring construction
- See also ortho anisidine
Corrosion inhibitors & antioxidants
p-Anisidine and its derivatives are used as corrosion inhibitors for steel and as antioxidants for polymercaptan resins, taking advantage of the electron-rich amine's reactivity.
- Steel corrosion inhibitor chemistry
- Polymercaptan resin stabilisation
- See our specialty intermediate range
Fine & specialty synthesis
A well-characterised amino-ether building block for custom amides, Schiff bases and ligand work where the electron-rich para-methoxyaniline pattern is required.
- Custom amide and Schiff base formation
- Ligand and coordination chemistry
- Available in trial and laboratory quantities
Contract & scheduled supply
Dye, pigment and pharma-intermediate plants run to campaign, not to a calendar month. Most p-anisidine buyers want tonnage released against a production plan rather than in one shipment. We hold inventory and release it to your schedule.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
How we supply Para Anisidine
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. We own no anisidine plant — and for a highly acutely toxic, specification-sensitive intermediate like this one, that independence works in your favour. We are never obliged to push you whatever a captive unit happens to be running that month.
Instead we place your order with whichever qualified producer best matches your assay, your colour ceiling, your price point and your delivery window.
We keep a second qualified source on this line. When a plant goes down for maintenance, your campaign switches source rather than stalling.
- Specification read against the CAS first. We confirm you need 104-94-9 and not the ortho or meta isomer before we quote a price.
- Batch COA shared before dispatch. You approve the assay, moisture and colour profile against your own spec while the material is still in our warehouse.
- Hazard status stated up front. This material is classified fatal by ingestion, skin contact and inhalation, and we say so at enquiry stage — not in the small print of a document pack that arrives with the goods.
- Pre-shipment samples for qualification. New account or new source, your R&D or QC lab runs a trial before the full quantity ever moves.
- Packing chosen to control dust and light exposure. As a heat-, light- and moisture-sensitive solid, we plan pack format and liner choice accordingly.
- Export machinery handled in-house. Hazard classification, UN-approved packing, labelling, freight booking and customs paperwork are ours to manage.
- Consolidation onto one bill of lading. Ship p-anisidine alongside other intermediates from our range — one invoice, one shipment, one counterparty.
Packed the way your plant receives it
Pack format drives your landed cost and your handling effort — and for a material classified fatal by all three exposure routes, it drives operator exposure directly. Tell us how it will be charged at your end and we will quote the format that suits your operation.
Multi-wall paper & PE bags
Laminated multi-wall bags with an inner liner, palletised and shrink-wrapped. The default for LCL movements and for plants charging batch-wise by hand.
Fibre & HDPE drums
UN-certified drums with liner for longer sea transits and humid destinations. Better protection against moisture and light exposure than bagged material.
Jumbo / FIBC bags
Bulk bags with liner for high-volume users with closed mechanical charging. Fewer handling movements and materially lower operator contact.
Samples & trial packs
Laboratory samples and pilot quantities dispatched by courier so your R&D or QC lab can qualify the grade before committing to campaign volume.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to. Ocean, air and road freight arranged end-to-end with documentation filed before booking.
Campaign despatch
Dye and pharma-intermediate production runs to campaign. We hold contracted tonnage and release it against your production calendar instead of landing it all at once.
Handle this as acutely fatal on exposure
This is the point on the page that matters most. Para anisidine is classified fatal if swallowed, fatal in contact with skin, and fatal if inhaled — a materially more severe acute toxicity category than most other anilines we supply — and it also carries a carcinogenicity classification and a specific target organ toxicity entry. The summary below is orientation only — the safety data sheet supplied with your consignment is the authoritative document and should govern your risk assessment, PPE selection, exposure monitoring and emergency planning.
Classified hazards
H300Fatal if swallowed.H310Fatal in contact with skin.H330Fatal if inhaled.H350May cause cancer.H373May cause damage to organs through prolonged or repeated exposure.H400Very toxic to aquatic life.
Hazard statements reflect the harmonised GHS classification commonly published for CAS 104-94-9 (GHS06 Toxic, GHS08 Health hazard, GHS09 Environmental hazard). The acute toxicity categories (H300/H310/H330) are notably more severe than the "toxic" classification carried by most other anilines on our range — treat this product with correspondingly stricter controls. Supplier classifications may differ in detail; always read the SDS issued with your specific batch.
Spill & emergency orientation
Plan your response before the pallet arrives, not after a bag splits. The points below are orientation for your emergency planners — sections 4, 5 and 6 of the SDS are the authoritative instructions and should be posted at the point of use.
- Sweep, do not hose. The material is very toxic to aquatic life. Collect spilled solid mechanically into a labelled container; never wash it to a drain.
- Suppress dust and avoid all skin contact. Given the fatal-on-exposure classification, treat any visible dust or spill as a serious incident requiring immediate, disciplined response.
- Full-body protection for spill response. Do not attempt a clean-up in standard PPE — consult the SDS for the specific protective equipment required for this hazard category.
- Have the SDS with the casualty immediately. Given the severity of the acute toxicity classification, emergency medical response should begin without delay, with the product identity and CAS number in hand.
- Record every exposure. For a material with this combined acute-toxicity and carcinogenicity profile, exposure records should be created and retained as a matter of course. That is a decision for your EHS function, made before an incident rather than after one.
Storage
- Cool, dry, dark, well-ventilated store, away from heat and any light source — this material is explicitly sensitive to heat, light and moisture. The melting point is only about 57 °C, so an uncooled store in a hot climate can soften or fuse the contents.
- Keep containers tightly closed at all times outside of active transfer.
- Segregate from oxidising agents, strong acids and acid chlorides. As a primary aromatic amine it reacts exothermically with acylating and oxidising reagents.
- Strictly access-controlled, bunded storage. Given the fatal-on-exposure classification, this is not optional — restrict access to trained, authorised personnel only.
- Shelf life is typically 12–18 months in sealed original packing under these conditions, shorter than most other anilines given its sensitivity to light and moisture. Re-assay before use after long storage.
Handling & PPE
- Design exposure out — this is not optional here. Fully closed transfer and mechanical charging, with no manual handling of open material, given the acute toxicity category.
- Full chemical-resistant PPE at all times. Gloves, coveralls and eye/face protection rated for this hazard category — consult the SDS for the specific equipment required, not generic chemical-handling gloves.
- Respiratory protection is mandatory wherever dust may be present, not merely recommended per exposure assessment.
- Health surveillance and exposure records should be treated as a baseline requirement for any regular handler, given the combined acute toxicity and carcinogenicity profile. We flag the classification; the programme is yours to run with your occupational health provider.
- Never discharge to drain or watercourse. H400 applies — collect spills as solid waste and dispose of them as regulated chemical waste.
Transport
p-Anisidine moves as regulated cargo under UN 2431. We classify each consignment, apply UN-approved packaging and labelling, and file the dangerous-goods declaration before the booking is made. The applicable class and packing group are stated on your shipping documents and SDS — ask us for the current DG paperwork when you plan the shipment.
What travels with every consignment
A chemical shipment is only as good as the file that travels with it. Verifying what the source plant sends is precisely the work you are buying from a supplier.
Certificate of Analysis
Batch-specific assay by GC, moisture by Karl Fischer, appearance, melting range and impurity profile — checked against your purchase specification before we release the goods.
GHS Safety Data Sheet
Full 16-section SDS in GHS format covering hazards, exposure controls, handling, storage, spill response, toxicology and disposal — issued in the language your destination requires.
Dangerous Goods Declaration
UN 2431, hazard class, packing group and IMDG or IATA declaration prepared and filed before the container is booked, with correctly marked and labelled packaging.
Certificate of Origin
Chamber-attested where required, plus preferential-origin forms where a trade agreement gives your import duty relief at the destination.
Third-party inspection
SGS, Intertek or Bureau Veritas sampling and inspection arranged on request before loading, giving you independent verification of what actually ships.
Retained & pre-shipment samples
Pre-shipment samples carry the same COA as the commercial lot, so what your laboratory qualifies is exactly what arrives. Retention samples held against the batch.
Two reactions that define this amine
p-Anisidine's value rests on two very different reactions: diazotisation for colour, and Schiff-base condensation with aldehydes for analytical chemistry. The routes below are the general industrial pattern, not a process disclosure.
Start with the amino-ether
p-Anisidine provides a primary aromatic amine with an electron-donating methoxy group locked para to the nitrogen, giving a more reactive, electron-rich ring than a toluidine.
Diazotise for colour
Sodium nitrite in acid at low temperature gives the diazonium salt, coupled onto naphthol or pyrazolone components to build deep, bright azo dyes and pigments.
Condense for analysis
The amine reacts readily with aldehydes to form coloured Schiff bases — the basis of the Anisidine Value test used to quantify secondary lipid oxidation products.
Finish to grade
The crude product is crystallised and standardised to whatever the end market demands — colour target for pigment work, or high purity for analytical reagent grade.
Why feed quality carries through the whole route
Both reactions depend on a clean, unreacted nitrogen. Anything in the feed that competes for that chemistry follows the material down the line:
- Isomeric anisidines diazotise or condense in parallel and give structurally similar but off-target products — an off-shade chromophore in colour work, a skewed reading in AV testing.
- Residual water can complicate diazotisation control at the low temperatures this reaction typically runs at.
- Oxidation products — the coloured species responsible for the reddish-brown drift in storage — introduce baseline colour that can bias an AV test result if the reagent itself is not fresh and pure.
- Heavy residues concentrate in mother liquors and can affect the purity needed for reagent-grade use.
That chain of consequences is the reason we quote against your written specification rather than a generic "99% technical" grade, and the reason the batch COA is shared for approval before dispatch rather than sent with the invoice.
| Intermediate | Principal outlet |
|---|---|
| Para Anisidine CAS 104-94-9 — this product | Azo & triphenylmethane dyes AV testing reagent Pharma intermediates |
| Ortho Anisidine CAS 90-04-0 | High-performance pigments Agrochemical intermediates |
| Para Toluidine CAS 106-49-0 | Azo pigments & dyes Rubber & pharma intermediates |
If your route calls for one of the others, we supply those as well — see our full product catalogue. Send the CAS number and we will confirm the correct material before quoting.
What actually moves the price of this intermediate
p-Anisidine is not a commodity with a screen price. Knowing what drives the quote helps you time a purchase and read whether an offer is realistic.
Dye, pharma and analytical demand
Colour chemistry, pharma intermediate synthesis and analytical reagent demand pull on the same material through the year, keeping it a steady, if lower-volume, product.
- Quote early for campaign tonnage
- Spot buying at peak costs materially more
- Contracted call-off smooths the exposure
Upstream feedstock
The route back to p-anisidine runs through 4-nitroanisole and selective reduction. Movements in benzene, methanol and catalyst metals feed through to the aniline within a quarter or so.
- Benzene and methanol prices set the floor
- Catalyst and energy costs weigh on the reduction step
- We flag feedstock-driven moves in the quote
Regulatory pressure
The severe acute toxicity and carcinogenicity classifications raise the compliance cost of producing, storing and moving this material meaningfully. That cost sits inside the price.
- Handling obligations are strict in most jurisdictions
- Some markets restrict certain end uses
- We check destination rules before quoting
Pack format
Cost per kilo falls from 25 kg bags to drums to jumbo bags — and given the acute toxicity classification, bulk bags also cut the number of times an operator opens a pack.
- Small bags carry the highest packing cost
- FIBC is cheapest per kilo at volume
- Less manual handling means less exposure
Freight & DG surcharges
This is regulated cargo, so ocean freight carries a hazardous surcharge and space is tighter than for general cargo. Destination and Incoterm move landed cost as much as the ex-works price does.
- Compare on landed cost, not ex-works
- DG space books out ahead of peak season
- We quote FOB, CIF, CFR or DDP as you prefer
Source availability
A plant turnaround or an environmental inspection can take capacity offline at short notice on this line. Single-sourced buyers feel this hardest.
- We hold a second qualified source on this line
- Qualify the alternate before you need it
- Ask us about dual-source contracts
| If your end use is… | Specify |
|---|---|
| Azo & triphenylmethane dyes | Colour ceiling, tight isomer limit |
| Anisidine Value (AV) testing | Analytical/reagent grade, batch-certified purity |
| Pharmaceutical chain | Tight isomer limit; metals and residues reported |
| Corrosion inhibitor / antioxidant use | High assay technical grade |
| Laboratory / R&D | Small pack, high purity, full analytical pack |
Not sure which column you are in? Describe the reaction or test you are running and our technical desk will recommend the grade — including telling you when a cheaper specification would do the job just as well.
Support that goes beyond shipping the bag
What our technical desk will do
- Match a grade to your reaction or test. Tell us the step you are running — synthesis or AV testing — and we will recommend the specification.
- Be straight about the hazard profile. We state the severe acute toxicity classification at enquiry stage so your EHS team can price the controls into the decision, rather than meeting it for the first time on the label.
- Advise on handling and storage for your site conditions — given the sensitivity to heat, light and moisture, packing and stowage need particular attention on this product.
- Review your specification before it goes into a contract, so you are not locked into a limit that no plant can consistently hit.
Regulatory & compliance notes
- Severe acute toxicant obligations are typically strict. Several regimes impose tight exposure limits, mandatory health surveillance and record retention for chemicals in this hazard category. Confirm what applies at your site before the first delivery.
- Import controls vary by destination. Some jurisdictions apply registration, licensing or end-use declaration requirements to this material. We check the destination rules before quoting, not after you have raised the PO.
- Chemical inventory listings differ between regions. Confirm your obligations under the applicable inventory regime for your import volume — we will supply the identity data you need for that filing.
- Downstream article restrictions can apply to certain colourant and consumer applications. Your regulatory team should confirm the finished-article position for the end use you have in mind.
None of the above is legal advice — your own regulatory affairs team owns the final compliance position for your import and your workplace. What we commit to is giving you accurate product identity data, an honest statement of the hazard classification and complete documentation to work from.
From enquiry to delivered pallet
Send the specification
Product name or CAS 104-94-9, the assay and colour limits you work to, quantity, pack preference and destination port.
Receive a firm quote
Pricing, lead time, packing and Incoterm confirmed in writing within 24 hours — our sourcing desk is staffed around the clock.
Qualify and approve
Sample dispatched if you are qualifying a new source. Batch COA shared for your approval before the material is released.
Ship and track
DG classification filed, freight booked, export documents issued, and the consignment tracked through transit and clearance to your plant.
Often bought alongside this grade
Consolidate several intermediates onto one shipment and one invoice. These are the anilines and aromatics our dye, pharma and analytical customers most often order in the same programme. Each of the following is part of our wider aniline intermediate range — browse the full product catalogue for current availability and specification sheets.
What buyers ask us about Para Anisidine
Why is this material more heavily classified than other anilines you supply?
Can I use the ortho or meta isomer instead?
What purity do you normally supply?
What is the minimum order quantity?
How long does delivery take?
Why does the solid darken so quickly?
How should we store it, and what is the shelf life?
Is this a dangerous good? What paperwork comes with it?
- Batch certificate of analysis
- GHS-format safety data sheet
- Dangerous-goods declaration with UN number, class and packing group
- Commercial invoice, packing list and bill of lading or airway bill
- Certificate of origin and any destination-specific forms
Do you supply to my country?
Do you manufacture this yourself?
Can you hold stock against a production plan?
Request pricing on Para Anisidine
Send your required assay, quantity, pack format and destination port. Our sourcing desk is available 24 hours a day, 7 days a week, and comes back with pricing, lead time and packing options — whether that is a single trial bag or a contracted container programme for the year.