Para Nitrobenzoic Acid
Para nitrobenzoic acid is the short way to para-aminobenzoic acid — one reduction step from a cheap, stable crystalline solid to the amino acid that sits underneath benzocaine, procaine and the folate route. Almost every kilogram sold is bought for what happens to that nitro group next.
Chelora Chemicals supplies para nitrobenzoic acid to pharmaceutical, dye and fine-chemical producers worldwide, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 62-23-7
- IUPAC name
- 4-Nitrobenzoic acid
- Molecular formula
- C₇H₅NO₄
- Molecular weight
- 167.12 g/mol
- EC / EINECS
- 200-526-2
- Transport status
- Generally non-DG*
- SMILES
- OC(=O)c1ccc(cc1)[N+](=O)[O-]
- HS Code
- 2916 39*
* Confirm the exact HS heading and the transport classification with your customs broker and freight forwarder — nitro-substituted aromatic acids can be read differently by mode and by destination tariff schedule.
What Para Nitrobenzoic Acid is used for
Para nitrobenzoic acid is a pale yellow to light buff crystalline powder — benzoic acid carrying a nitro group in the para position. The nitro group pulls hard on the ring, which both makes the carboxylic acid noticeably stronger than benzoic acid itself and sets the molecule up for clean reduction at exactly one site.
Its single largest use is as the feedstock for para-aminobenzoic acid (PABA), produced by catalytic hydrogenation or chemical reduction of the nitro group. PABA in turn feeds ester-type local anaesthetics such as benzocaine and procaine, folate chemistry, and a range of specialty esters. The acid is also chlorinated to p-nitrobenzoyl chloride for acylation work, and used directly as a dye and pigment intermediate.
Where it sits among nitro-aromatic acids
- Para nitrobenzoic acid (this product) the commercially dominant isomer; reduces cleanly to PABA.
- Ortho and meta nitrobenzoic acid minor isomers, present as impurities here and bought separately where specifically needed.
- Para nitrobenzamide the primary amide at the same position. See that page.
- Para nitrophenol the phenolic analogue, serving separate dye and agrochemical routes. See that page.
On a pharmaceutical intermediate, confirm the CAS number and the isomer limit on your purchase order — see the full intermediate range.
Appearance and handling character
The material ships as a stable, free-flowing crystalline powder with a high melting point, practically insoluble in cold water and soluble in hot ethanol, acetone and aqueous alkali as the salt. It is an irritant rather than an acute toxin, and the practical handling question is dust control at charging and sampling points rather than anything more exotic.
| Parameter | Typical value |
|---|---|
| Appearance | Pale yellow to light buff crystalline powder |
| Assay (HPLC / titration) | 99.0% min |
| Melting range | 237 – 240 °C |
| Ortho + meta isomers | 0.5% max |
| Moisture (KF) | 0.5% max |
| Sulphated ash | 0.1% max |
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. Assay and isomer content are the figures that most affect downstream purity — tell us your target and we will quote against it.
| Property | Value |
|---|---|
| Physical state | Crystalline solid at ambient |
| Melting point | 237 – 240 °C |
| Density | ≈ 1.61 g/cm³ |
| Water solubility | Practically insoluble cold; soluble in alkali as the salt |
| Solvent solubility | Soluble in hot ethanol, acetone, acetic acid |
| Incompatibilities | Strong oxidisers, strong bases, strong reducing agents |
Physical constants compiled from public reference data for CAS 62-23-7 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this intermediate to work
This is a building block with one very large downstream and several steady smaller ones.
Para-aminobenzoic acid (PABA)
The dominant downstream step — catalytic hydrogenation of the nitro group to give PABA, the entry point to a long list of actives.
- Low-catalyst-poison specification available
- Sulphur and metals reported per batch
- Ask about hydrogenation-grade material
Local anaesthetic synthesis
Benzocaine, procaine and related ester anaesthetics are built on the PABA skeleton that starts here.
- API intermediate routes
- End-use declaration required
- Full impurity profile on request
p-Nitrobenzoyl chloride
Chlorination gives the acid chloride used for acylation and for preparing p-nitrobenzoate derivatives in synthesis and analysis.
- Low-moisture grade preferred
- Moisture reported per batch
- Technical desk review of your route
Dye & pigment intermediates
Used where an electron-poor aromatic acid is needed in colourant synthesis, and as a precursor to amino-acid coupling components.
- Dye intermediate routes
- Colour-critical grades on request
- See our dye intermediate range
Analytical derivatisation
p-Nitrobenzoate esters are classical crystalline derivatives for characterising alcohols and amines in the laboratory.
- Packs from 500 g
- Reference-grade material on request
- Full analytical documentation available
Contract & scheduled supply
Pharma plants consume this on fixed schedules. We hold inventory and release it against your production calendar.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
How we supply Para Nitrobenzoic Acid
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. On a pharmaceutical intermediate, owning no plant means we are never selling you whatever a captive unit happens to be running — we route your order to the producer whose isomer profile actually matches what your filing can carry.
We place your order with whichever qualified producer best matches your assay, your isomer limit, your price point and your delivery window.
We keep a second qualified source on this line. When a plant goes down for maintenance, your order switches source rather than stalling.
- Assay and isomer content confirmed before we quote. On this product the isomer figure is the one that matters, and we state it on the COA rather than leaving it to inference.
- We ask what it feeds before we quote. A regulated starting material and a laboratory derivatising reagent need different documentation.
- Catalyst-poison figures available. If the next step is a hydrogenation to PABA, we will get you sulphur and heavy-metal data rather than a bare assay.
- Batch COA shared before dispatch. You approve assay and isomer content against your own spec while the material is still in our warehouse.
- Pre-shipment samples for qualification. New account or new source, your laboratory runs a trial before the full quantity ever moves.
- Export machinery handled in-house. Classification, packing, labelling, freight booking and customs paperwork are ours to manage.
Packed the way your plant receives it
Pack format drives your landed cost and your handling effort. Tell us how the material will be charged at your end and we will quote the format that suits your operation.
Fibre / HDPE drums
Drums with an inner LDPE liner — the standard commercial format and the easiest to handle into a charging port.
Multiwall paper bags
Lined kraft bags on shrink-wrapped pallets, the lowest-cost format where your store is dry and turnover is quick.
Jumbo bags (FIBC)
Lined, discharge-spout FIBCs for high-volume consumers with bulk-bag handling already installed.
Trial / sample quantities
Small packs dispatched so your R&D team can qualify the grade before committing to larger volumes.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with export documentation filed before the booking is made.
Campaign despatch
We hold contracted tonnage and release it against your production calendar instead of landing it all at once.
A stable solid where dust is the issue
Para nitrobenzoic acid is classified for irritation rather than acute toxicity and is stable under ordinary warehouse conditions. That makes dust control and routine hygiene practice the whole of the handling story. The summary below is orientation only — the safety data sheet supplied with your consignment is the authoritative document.
Classified hazards
H302Harmful if swallowed.H315Causes skin irritation.H319Causes serious eye irritation.H335May cause respiratory irritation.
Hazard statements reflect classifications commonly published for CAS 62-23-7. Suppliers differ on this product and some SDS carry additional precautionary statements. Always read the SDS issued with your specific batch rather than assuming the classification above applies to the material in your drum.
Spill & emergency orientation
Plan your response before the pallet arrives. Sections 4, 5 and 6 of the SDS are the authoritative instructions and should be posted at the point of use.
- Avoid raising dust. Collect spilled powder with a vacuum or damp method rather than dry sweeping, which turns a floor spill into an airborne irritant.
- Flush eyes thoroughly and promptly. Eye irritation is the most likely real-world incident on this material — have an eyewash station at the charging point.
- Wash skin with soap and water. Remove contaminated clothing and launder it before re-use.
- Keep it out of the drain. Collect the material and dispose of it as chemical waste in line with local rules.
- Keep away from strong oxidisers and bases. It is an acid as well as a nitro-aromatic; segregate accordingly.
Storage
- Cool, dry, well-ventilated store. Away from direct sunlight and heat sources; ordinary warehouse conditions are sufficient.
- Keep containers tightly closed. Moisture pick-up shows up in your Karl Fischer result and on your charge weight, and matters a great deal if the next step is a chlorination.
- Segregate from strong bases and oxidising agents. Standard practice for a nitro-aromatic acid.
- Keep the liner sealed between charges. Partial drums left open are the usual source of off-spec moisture results.
- Shelf life typically 36 months. In sealed original packing. Re-assay before use after extended storage.
Handling & PPE
- Control dust at the source. Local exhaust ventilation at charging and sampling points does most of the work here.
- Gloves, safety glasses and a dust mask. Chemical-resistant gloves and sealed goggles where the operation can generate airborne powder.
- Normal hygiene practice. No eating or drinking in the handling area; wash hands before breaks.
- Sample under extraction. Drum sampling is where most exposure happens on a powder like this.
- Dispose of as chemical waste. Do not discharge washings to an uncontrolled drain.
Transport
Para nitrobenzoic acid is commonly shipped as non-regulated general cargo, but transport classification is mode and destination specific. We confirm the classification for each consignment and issue the declaration where one is required — ask us for the current shipping 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, melting range, isomer content, moisture and ash — checked against your purchase specification before release.
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.
Analytical method & chromatogram
HPLC method and the batch chromatogram supplied on request, so your QC can reproduce the isomer figure rather than take it on trust.
Certificate of Origin
Chamber-attested where required, plus preferential-origin forms where a trade agreement gives your import duty relief.
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.
An acid on one end, a nitro group on the other
The value of this molecule is that the nitro group can be reduced without disturbing the acid, giving an amino acid in one clean step. The routes below are the general industrial pattern, not a process disclosure.
Start from para-nitrotoluene
The para isomer is separated from the toluene nitration mixture and taken forward as the feedstock.
Oxidise the methyl group
Controlled oxidation converts the methyl to a carboxylic acid, giving crude para nitrobenzoic acid.
Purify and recrystallise
Crystallisation removes residual isomers and oxidation by-products, lifting assay and tightening the melting range.
Reduce to PABA in use
Downstream, catalytic hydrogenation converts the nitro group to the amine, leaving the carboxylic acid intact.
Why isomer content carries through the whole route
On this intermediate, the isomer figure matters more than the headline assay, because the impurities behave exactly like the product:
- Ortho and meta isomers reduce too. They become ortho- and meta-aminobenzoic acid and follow your product through the next step, where separation is much harder.
- A low melting point signals isomeric contamination. It is the quickest practical read on batch quality before the HPLC result returns.
- Catalyst poisons decide your hydrogenation cost. Sulphur and certain metals at ppm level cost far more in catalyst than a cheaper grade saves on material.
- Moisture governs any chlorination step. If the acid is going to the acid chloride, water in the drum is a direct yield loss and an HCl problem.
That is why we quote against your written isomer and assay limits rather than a generic "technical grade", and why the batch COA is shared for approval before dispatch rather than sent with the invoice.
| Material | Downstream / use |
|---|---|
| Para nitrobenzoic acid CAS 62-23-7 — this product | Route to PABA and acid chloride |
| Para aminobenzoic acid CAS 150-13-0 | Anaesthetics, folate chemistry |
| Para nitrobenzamide CAS 619-80-7 | Route to 4-aminobenzamide |
| Para nitrotoluene CAS 99-99-0 | Upstream feedstock to this product |
We supply across this intermediate family — see the full intermediate range. Send the CAS number and we will confirm the correct material before quoting.
What actually moves the price of this product
Knowing what drives the quote helps you time a purchase and read whether an offer is realistic.
Para-nitrotoluene supply
The route starts from the para isomer of nitrotoluene, and isomer separation economics feed straight through to price.
- Toluene tracks the aromatics market
- Para/ortho isomer split drives availability
- We flag feedstock-driven moves in the quote
Isomer specification
A 0.5% isomer limit and a 0.1% limit are different products from the same plant, at different prices and different yields.
- Tell us the real limit, not a wish list
- We will say when a wider limit will do
- Over-specification is the commonest cost leak
Freight and packaging
Non-DG status keeps freight simple, so pack format and container utilisation matter proportionally more here than on regulated lines.
- Compare on landed cost, not ex-works
- Bag vs drum vs FIBC changes per-kilo freight
- We quote FOB, CIF, CFR or DDP as you prefer
Oxidation route economics
The oxidation step is energy and reagent intensive, so utility costs at the source plant show up in the quote more than on simpler chemistry.
- Ask us how the source plant is running
- Contracted call-off smooths the exposure
- We hold a second qualified source
Source availability
A plant turnaround, environmental inspection or feedstock disruption can take capacity offline at short notice.
- We hold a second qualified source on this line
- Qualify the alternate before you need it
- Ask us about dual-source contracts
PABA and anaesthetic demand
Volumes track the PABA chain. Demand swings in local anaesthetics and folate production show up here within a quarter.
- Ask us what downstream demand is doing
- Long-term contracts lock in supply
- Qualify a second source early
| If your end use is… | Specify |
|---|---|
| PABA / API route | Tight isomer limit, catalyst-poison data |
| p-Nitrobenzoyl chloride | Low moisture, standard isomer limit |
| Dye & pigment intermediate | Standard 99% commercial grade |
| Laboratory derivatisation | Small pack, full COA and chromatogram |
Not sure which column you are in? Describe what you make from it 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 drum
What our technical desk will do
- Confirm assay and isomer limits before anything else. On this intermediate the isomer figure decides downstream purity, and we settle it in the first reply.
- Ask what the next step is. A hydrogenation needs catalyst-poison data; a chlorination needs a moisture figure. We would rather ask than guess.
- Get you the analytical package. Method, chromatogram and retained sample, so your QC can verify rather than accept.
- Review your specification before it goes into a contract. So you are not locked into a purity no plant can consistently hit.
Regulatory & compliance notes
- Regulated starting material status is yours to declare. If this is filed as an RSM, tell us — the documentation package and the change-control expectations are different.
- Import controls vary by destination. We check destination rules before quoting, not after you have raised the PO.
- Chemical inventory listings differ between regions. We will supply the identity data you need for that filing.
- Effluent and waste rules matter. Check your discharge consent against the material before introducing it to site.
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 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 62-23-7, your assay and isomer requirement, 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
Freight booked, export documents issued, and the consignment tracked through transit and clearance to your plant.
What buyers ask us about Para Nitrobenzoic Acid
What is para nitrobenzoic acid used for?
Is it a dangerous good for transport?
What purity do you normally supply?
Why does isomer content matter so much on this product?
Can you supply it as a regulated starting material?
What is the minimum order quantity?
How should we store it?
What paperwork comes with the shipment?
Do you manufacture this yourself?
Request pricing on Para Nitrobenzoic Acid
Send your required assay, isomer limit, 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 pack or a contracted programme for the year.