Dye, pigment & agrochemical intermediate
Ortho Nitro Chloro Benzene (ONCB) Supplier & Distributor in India & Worldwide
Chelora Agrochem is a trusted Ortho Nitro Chloro Benzene (ONCB) supplier and distributor in India, connecting buyers with high-purity material sourced from leading, quality-approved manufacturers. Our 1-chloro-2-nitrobenzene meets 99% min purity with low para-isomer content, full documentation and reliable bulk supply across India and to buyers worldwide.
As a specialised distributor of chemical products, we do not manufacture in-house — instead we source only from reliable, audited manufacturers, giving you dependable material, competitive pricing and a single point of contact for all your ONCB requirements, backed by COA, MSDS and TDS on every order.
- CAS number
- 88-73-3
- Formula
- C6H4ClNO2
- Molecular weight
- 157.55 g/mol
- Purity
- 99% min
Quick product specifications
Ortho Nitro Chloro Benzene at a glance
Identifiers, physical data and trade codes for ONCB. Batch-specific figures are confirmed on the Certificate of Analysis supplied with each consignment, in India and on export shipments alike.
- Chemical name
- Ortho Nitro Chloro Benzene
- CAS number
- 88-73-3
- Molecular formula
- C6H4ClNO2
- Molecular weight
- 157.55 g/mol
- IUPAC name
- 1-Chloro-2-nitrobenzene
- EC number
- 201-854-9
- HS code
- 2904 99National subheading as per destination
- UN number
- UN 1578Chloronitrobenzenes, solid or molten · Class 6.1, PG II
- Appearance
- Yellow crystalline solidAlso supplied molten in heated tankers on request
- Melting point
- 32–34 °C
- Boiling point
- 245–246 °C
- Density
- About 1.37 g/cm³Solid, 20 °C
- Flash point
- About 127 °CClosed cup, combustible solid
- Solubility
- Practically insoluble in waterSoluble in ethanol, ether, benzene and aromatic solvents
- Purity
- 99% min
- Synonyms
- ONCBo-Nitrochlorobenzene · 2-Nitrochlorobenzene · 2-Chloronitrobenzene
- Product form
- Flakes, crystals or molten
- Documentation
- COA, MSDS & TDSSupplied with every order
Product overview
What is Ortho Nitro Chloro Benzene?
Ortho Nitro Chloro Benzene (ONCB) is a chlorinated nitroaromatic used as a base intermediate for dyes, pigments, pharmaceuticals and agrochemicals. The chlorine atom sits next to the nitro group, which activates it for substitution by ammonia, amines, alkoxides and hydroxide.
With the formula C6H4ClNO2 (CAS 88-73-3), ONCB is a yellow crystalline solid that melts at about 33 °C and is practically insoluble in water. Because it melts just above room temperature, it is often handled and shipped molten in heated, closed systems. It is made by nitrating chlorobenzene, which gives a mixture of the ortho and para isomers that are then separated.
The ortho-nitro group activates the neighbouring chlorine, so ONCB converts readily to o-nitroaniline, o-nitrophenol, o-nitroanisole and o-nitrophenetole — which is why buyers specify it by para- and meta-isomer content as closely as by assay.
How it is made
Chlorobenzene is nitrated with mixed nitric and sulfuric acid, giving roughly two parts para- to one part ortho-nitrochlorobenzene with a little meta isomer. The isomers are separated by a combination of crystallisation and fractional distillation, and the ortho cut is refined to specification.
What that means for your process
- Activated chlorine for clean nucleophilic substitution
- Low para- and meta-isomer content, checked by GC
- Low moisture and acidity for stable storage
- Flaked or molten form to suit your charging system
Applications
What is Ortho Nitro Chloro Benzene used for?
ONCB is used almost entirely as a chemical intermediate. Its main applications, industry by industry, include:
Dyes & pigments
A starting point for o-nitroaniline, o-anisidine and o-phenetidine, key azo dye and pigment intermediates.
- Ammonolysis to o-nitroaniline
- Methoxylation to o-nitroanisole, then o-anisidine
- Azo, sulfur and pigment intermediates
Pharmaceuticals & fine chemicals
Reduced to o-phenylenediamine and o-chloroaniline, building blocks for benzimidazole chemistry.
- o-Nitroaniline hydrogenated to o-phenylenediamine
- Benzimidazole and benzotriazole derivatives
- o-Chloroaniline for fine chemical synthesis
Agrochemicals
Feeds carbendazim-type benzimidazole fungicides and other crop-protection intermediates.
- o-Phenylenediamine route to benzimidazole fungicides
- o-Nitrophenol and o-aminophenol derivatives
- Custom ortho-substituted anilines
Process route
How is ONCB used to make benzimidazole intermediates?
One of the largest outlets for ONCB is the o-phenylenediamine (OPDA) route. ONCB is aminated with ammonia to o-nitroaniline, which is hydrogenated to o-phenylenediamine and then cyclised to the benzimidazole derivatives used in fungicides, corrosion inhibitors and pharmaceuticals.
Ortho Nitro Chloro Benzene
Charged as the activated aryl chloride. Assay and para-isomer content decide downstream yield.
C6H4ClNO2Ammonolysis
Reacted with aqueous or liquid ammonia under pressure to displace the chlorine.
NH3, pressureo-Nitroaniline
Hydrogenated over a catalyst to o-phenylenediamine (OPDA).
OPDABenzimidazole derivative
Cyclised with a carbon source to carbendazim-type actives and specialty chemicals.
BenzimidazolesIn depth
Ortho Nitro Chloro Benzene applications by industry
Below is a detailed breakdown of where ONCB is used and the role it plays in each downstream product.
| Industry | Typical downstream products | Role of ONCB |
|---|---|---|
| Dyes & pigments | o-Nitroaniline, o-anisidine, o-phenetidine | Starting material |
| Agrochemicals | Benzimidazole fungicides via o-phenylenediamine | Intermediate |
| Pharmaceuticals | o-Phenylenediamine, o-aminophenol derivatives | Intermediate |
| Rubber & polymer additives | Benzotriazole and benzimidazole additives | Building block |
| Fine chemicals | Custom nitro- and amino-aromatics | Building block |
Safety
Is Ortho Nitro Chloro Benzene hazardous?
Yes. ONCB is toxic if swallowed, in contact with skin or if inhaled, is suspected of causing genetic defects and cancer, and can damage the blood through repeated exposure by causing methaemoglobinaemia. It is also toxic to aquatic life with long-lasting effects.
ONCB should be stored in sealed containers in a cool, dry, ventilated place away from heat, strong bases, reducing agents and oxidisers, and handled with chemical-resistant gloves, goggles, protective clothing and dust or vapour respiratory protection. Because it melts at about 33 °C, molten product must be handled in closed, heated and properly vented systems. Prevent release to drains and waterways. A full MSDS is supplied with every order.
Signal word: Danger
Toxic by ingestion, skin contact and inhalation · suspected mutagen and carcinogen · toxic to aquatic life
Safe-handling essentials
- Chemical-resistant gloves, goggles and protective clothing at all times
- Dust or vapour respirator; use local exhaust ventilation
- Avoid all skin contact — ONCB is absorbed through the skin
- Keep bags and drums sealed, cool and dry
- Handle molten material only in closed, heated, vented systems
- Store away from strong bases, reducing agents and oxidisers
- Never allow release to drains, soil or waterways
- Transport as UN 1578, class 6.1, packing group II
Grades
Ortho Nitro Chloro Benzene grades & technical specifications
We supply ONCB in standard industrial grade and in low-para grades for dye and pharmaceutical work.
| Parameter | Specification |
|---|---|
| Assay (purity) | 99% min |
| Appearance | Yellow flakes or crystals |
| Para-nitrochlorobenzene | 0.5% max |
| Meta-nitrochlorobenzene | 0.3% max |
| Setting point | 32.0 °C min |
| Moisture | 0.1% max |
| Acidity (as HNO3) | 0.01% max |
| Product form | Flakes, crystals or molten |
Note: Values are representative. Batch-specific figures are provided on the Certificate of Analysis (COA) supplied with each consignment.
Supply
Packaging, MOQ & supply
From trial quantities for process validation to repeat container loads on contract — packed, documented and dispatched to your plant in India or overseas.
Packaging
50 kg HDPE-lined bags, fibre or HDPE drums, jumbo bags, or molten in heated tankers as per quantity.
Minimum order quantity
Flexible — single drums or bags for trials through to full-container loads.
Shelf life
Long shelf life in sealed, unopened packs stored cool, dry and away from heat sources.
Dispatch
Pan-India dispatch and worldwide export with complete dangerous-goods documentation and logistics support.
Why buy from us
Why choose Chelora as your ONCB supplier?
As an established Ortho Nitro Chloro Benzene supplier and distributor based in India and shipping worldwide, we work with a wide network of trusted manufacturers to combine consistent quality with dependable service. More about Chelora Agrochem.
High purity, every batch
99% min assay, sourced only from quality-approved manufacturers we have worked with and audited.
Full documentation
COA, MSDS and TDS travel with every order, so your QA and EHS teams are never chasing paperwork.
Reliable bulk supply, flexible MOQ
Single packs for process trials through to repeat container loads on schedule.
Worldwide supply
Export-grade packing, dangerous-goods documentation and on-time dispatch to plants across Asia, the Middle East, Europe, Africa and the Americas.
Technical & safe-handling support
Guidance on storage, PPE and process fit from a team that knows nitroaromatic intermediates.
One point of contact
Source ONCB alongside your other intermediates — one enquiry, one team, one invoice.
Ordering
How to order Ortho Nitro Chloro Benzene from Chelora
Ordering is simple and fast — most enquiries are answered with pricing and availability within 24 hours.
- 1
Send your enquiry
Tell us the grade, quantity and application you are buying for.
- 2
Receive a quotation
We send pricing along with the COA and MSDS for your review.
- 3
Request a sample
Test suitability for your process before you commit to a bulk order.
- 4
Confirm the order
Lock in quantity, packaging and delivery preference.
- 5
Dispatch & tracking
We dispatch with full documentation and keep you updated until delivery.
Documentation
Ortho Nitro Chloro Benzene MSDS & COA
A summary of key safety information and a representative Certificate of Analysis. The complete 16-section Safety Data Sheet and the actual batch COA are supplied with each shipment — and both are sent with your quotation when you ask for a quote.
Safety data summary (MSDS)
| Section | Details |
|---|---|
| Hazard classification | Acute toxicity cat. 3 (oral / dermal / inhalation); germ cell mutagenicity cat. 2; carcinogenicity cat. 2; STOT RE cat. 2 (blood); aquatic chronic cat. 2 |
| Signal word | Danger |
| First aid — inhalation | Move to fresh air; seek medical help. Watch for signs of methaemoglobinaemia (blue lips or nails) |
| First aid — skin | Remove contaminated clothing; wash thoroughly with soap & water |
| First aid — eyes | Rinse with water for several minutes; get medical advice |
| Handling | Use PPE; avoid dust, vapour and skin contact; ventilate |
| Storage | Cool, dry, sealed; away from heat, bases, reducing agents & oxidisers |
| Environment | Toxic to aquatic life; prevent release to drains / waterways |
| Transport | UN 1578; class 6.1; packing group II |
Certificate of Analysis (representative)
| Test parameter | Specification | Method |
|---|---|---|
| Assay (purity) | 99% min | GC |
| Appearance | Yellow flakes | Visual |
| Para isomer | 0.5% max | GC |
| Meta isomer | 0.3% max | GC |
| Setting point | 32.0 °C min | Capillary |
| Moisture | 0.1% max | Karl Fischer |
The actual batch COA is supplied with each shipment.
FAQ
Frequently asked questions
Common questions from buyers specifying ONCB for dye, pigment, pharmaceutical and agrochemical production.
What is Ortho Nitro Chloro Benzene used for?
ONCB is used mainly to make o-nitroaniline and o-phenylenediamine for benzimidazole fungicides and fine chemicals, o-anisidine and o-phenetidine for azo dyes and pigments, and o-chloroaniline and o-aminophenol for pharmaceutical and agrochemical intermediates.
What is the CAS number of ONCB?
The CAS number is 88-73-3 and the molecular formula is C6H4ClNO2. It is also known as 1-chloro-2-nitrobenzene, o-nitrochlorobenzene or 2-chloronitrobenzene.
How is ONCB made?
Chlorobenzene is nitrated with mixed acid, giving mainly para- and ortho-nitrochlorobenzene with a little meta isomer. The ortho isomer is separated by crystallisation and fractional distillation.
Is Ortho Nitro Chloro Benzene hazardous?
Yes. It is toxic if swallowed, in contact with skin or if inhaled, is suspected of causing genetic defects and cancer, can cause methaemoglobinaemia, and is toxic to aquatic life. Handle it with full PPE, ventilation and containment; we supply a full MSDS with every order.
What is the difference between ONCB and PNCB?
Both come from the nitration of chlorobenzene. ONCB has the nitro group next to the chlorine (ortho) and melts at about 33 °C, so it is often shipped molten; PNCB has it opposite the chlorine (para) and melts at about 83 °C. They lead to different downstream products, so the isomer content of each is controlled tightly.
How should ONCB be stored?
In sealed bags or drums in a cool, dry, well-ventilated store, away from heat, strong bases, reducing agents and oxidisers. Because it melts just above room temperature, molten ONCB must be kept in closed, heated and properly vented systems.
Do you provide COA and MSDS for ONCB?
Yes, we provide a batch-specific COA and MSDS with every order, plus technical support on request.
Do you supply and export Ortho Nitro Chloro Benzene?
Yes, we supply ONCB across India and export internationally with complete dangerous-goods documentation, sourced from reliable manufacturers.
Request a quote or sample
Need a reliable ONCB supplier?
Looking for a dependable Ortho Nitro Chloro Benzene (ONCB) supplier and distributor — in India or anywhere we export to? Tell us the grade and quantity you need — our team responds with competitive bulk pricing, samples and complete documentation (COA, MSDS, TDS) within 24 hours.
Or email source@cheloraagrochem.com