N-Methyl Aniline octane booster technology is one of the most cost-effective ways to raise the octane rating of gasoline. Refiners and fuel blenders use N-Methyl Aniline (NMA), an ashless, metal-free octane improver, to increase the Research Octane Number (RON) of base gasoline at low treat rates. Outside the fuel sector, the same molecule is a key intermediate for dyes, agrochemicals, pharmaceuticals and rubber chemicals.
PETRONAX supplies high-purity N-Methyl Aniline to customers in North America, Latin America, Europe, the Middle East, Africa, Central Asia and Asia-Pacific. It is the active chemistry behind our octane booster range and part of our wider refinery chemicals portfolio. This guide explains how NMA works as an octane booster, what to check before blending, and what its other industrial uses are.
What Is N-Methyl Aniline?
N-Methyl Aniline, also written N-methylaniline, monomethylaniline (MMA), methylphenylamine or N-methylaminobenzene, is a secondary aromatic amine. A single methyl group is attached to the nitrogen atom of aniline. That small change alters the electron density around the amine and its reactivity, which is why NMA works both as a fuel octane improver and as a synthesis intermediate.
| Parameter | Typical value |
|---|---|
| Chemical name | N-Methyl Aniline |
| Synonyms | NMA, MMA, monomethylaniline, N-methylaminobenzene, methylphenylamine |
| CAS number | 100-61-8 |
| Molecular formula | C₇H₉N |
| Molecular weight | 107.15 g/mol |
| Appearance | Clear liquid, colourless to light yellow (darkens on air exposure) |
| Odour | Characteristic amine |
| Boiling point | ≈ 196–197 °C |
| Melting point | ≈ −57 °C |
| Density (20 °C) | ≈ 0.986–0.989 g/cm³ |
| Flash point | ≈ 79–80 °C (closed cup) |
| Solubility | Poorly soluble in water; miscible with alcohols, ethers and most organic solvents |
Values are indicative. Batch-specific figures are stated on the PETRONAX Certificate of Analysis (COA) issued with every consignment; see our technical datasheets and safety documentation. Independent data for CAS 100-61-8 are published in the PubChem compound database.
N-Methyl Aniline as an Octane Booster for Gasoline
The largest-volume use of N-Methyl Aniline worldwide is as a non-metallic, ashless octane booster for motor gasoline. Refiners and blenders add NMA to raise the RON of base gasoline streams, improve knock resistance and meet octane specifications without changing the refinery configuration. RON is measured with the standard laboratory engine method ASTM D2699, and blend economics are calculated against that figure.
How an octane improver works
Knock (pre-ignition) occurs when the fuel-air mixture in a high-compression engine ignites before the spark. An octane improver raises the fuel’s resistance to this auto-ignition, so the engine can run at higher compression and better efficiency without knocking. Aromatic amines such as NMA are among the most efficient additives for this job on a per-volume basis.
Key advantages of NMA as an octane booster
- High octane efficiency per unit volume. NMA delivers a significant RON uplift at low treat rates, which means less additive volume, less tankage and lower logistics cost per octane point gained.
- Metal-free and ashless. Unlike metal-based antiknock agents (lead, manganese and iron compounds), NMA leaves no metallic residue that can foul spark plugs, damage catalytic converters or disturb oxygen sensors.
- Blending flexibility. NMA is compatible with conventional gasoline hydrocarbons and can be co-blended with oxygenates and other performance additives.
- Cost efficiency. For many refiners, an NMA octane booster is a more economical route to specification octane than deeper reforming or high-severity isomerisation.
NMA compared with other octane improvers
| Octane improver type | Examples | Main consideration |
|---|---|---|
| Aromatic amines | N-Methyl Aniline | High efficiency at low treat rate; regulatory status varies by market |
| Oxygenates | Ethanol, MTBE, ETBE | Needed in large volumes; affect vapour pressure and energy content |
| Metal-based antiknock agents | Lead, manganese and iron compounds | Metallic deposits; restricted or banned in many markets |
| Refinery processes | Reforming, isomerisation, alkylation | Very high capital and operating cost |
Dosage and compliance: what to check before blending
Treat rates are always set by the blender in line with the finished-fuel specification and the rules of the destination market. The permitted content of N-Methyl Aniline in motor gasoline varies significantly by jurisdiction, and in some markets it is restricted or not permitted at all. European users should check the substance record and any restrictions on the European Chemicals Agency (ECHA) website as well as national fuel-quality rules. PETRONAX supports customers with documentation, but responsibility for meeting local fuel legislation rests with the blender or importer.
Our technical team can help with blend design, compatibility testing and regional requirements. Get in touch before contracting.
Other Industrial Uses of N-Methyl Aniline
Dyes and pigments
NMA is a classical intermediate in the colour industry. It is used to make azo dyes, triphenylmethane dyes, cationic dyes (such as cationic brilliant red and pink grades), reactive dyes for cellulosic fibres, and colourants for textiles, printing inks, leather, paper and coatings. Shade reproducibility depends directly on amine purity, since trace aniline, water or oxidation products cause off-shade batches. The same purity discipline applies to our own petroleum dyes and markers.
Agrochemicals and crop protection
NMA is an intermediate in routes to insect growth regulators and selective herbicides, including buprofezin (insecticide) and mefenacet (herbicide). Multi-step agrochemical synthesis is sensitive to impurities, so low residual aniline and low moisture matter.
Pharmaceutical intermediates
The N-methyl group is often used to tune lipophilicity, metabolic stability, basicity and receptor binding. N-Methyl Aniline and its derivatives therefore appear as building blocks in the synthesis of active pharmaceutical ingredients and drug candidates.
Rubber chemicals, polymers and resins
NMA contributes to rubber accelerators and antidegradants, polymer and resin intermediates, antioxidants and stabilisers for elastomers and plastics, and curing agent components for epoxy and specialty resin systems.
Solvents, corrosion inhibitors and specialty chemicals
NMA is also used as a latent and coupling solvent, in corrosion inhibitor formulations for oilfield and metalworking applications, in photographic and imaging chemicals, and as a reagent in organic synthesis and R&D.
Why Source Your N-Methyl Aniline Octane Booster from PETRONAX
- Consistent high purity. Tight control of residual aniline, dimethylaniline, water content and colour. Every batch is analysed before release in our chemical research and QC facilities.
- Full documentation. Each shipment includes a Certificate of Analysis, Safety Data Sheet and the transport and regulatory documents needed for the destination market, with batch traceability from production to delivery.
- Grade flexibility. Grades and concentrations for fuel blenders, dye houses, agrochemical producers and fine-chemical customers, including custom specifications on request.
- Global logistics. Drums, IBCs, ISO tanks and bulk parcels, with experience in export documentation, labelling and dangerous-goods requirements.
- Technical partnership. Support with specification alignment, compatibility questions and blend design, not just order fulfilment.
- Supply security. Long-term contracts, buffer inventory and multi-route logistics planning.
Packaging, Storage and Handling
Packaging. Typically 200 L / 220 kg steel drums, 1,000 L IBCs, ISO tanks and bulk. Alternative packaging is available on request.
Storage. Keep in a cool, dry, well-ventilated area away from heat, sparks and open flame. Keep containers tightly closed, because air exposure causes gradual darkening. Segregate from strong oxidising agents, strong acids and foodstuffs.
Safety. N-Methyl Aniline is a toxic substance. It is harmful by inhalation, ingestion and skin absorption, can cause methaemoglobinaemia, and may damage the liver, kidneys and central nervous system on repeated or significant exposure. It is also hazardous to aquatic life. Handling requires:
- Chemical-resistant gloves, eye protection, protective clothing and, where required, respiratory protection
- Local exhaust ventilation and engineering controls
- Compliance with occupational exposure limits
- Trained personnel and established spill and emergency procedures
- Compliance with national and regional chemical, transport and environmental regulations
Always read the current Safety Data Sheet in full before handling. This summary does not replace the SDS, applicable regulations or your own risk assessment. Exposure limits and recommended controls are published in the NIOSH Pocket Guide to Chemical Hazards. The current PETRONAX SDS is in our downloads section.
Frequently Asked Questions
What is N-Methyl Aniline used for? Its largest use is as an octane booster for gasoline. It is also an intermediate for dyes, agrochemicals, pharmaceuticals, rubber chemicals and resins, and is used as a specialty solvent.
What is the CAS number of N-Methyl Aniline? CAS 100-61-8. Synonyms include monomethylaniline (MMA), N-methylaminobenzene and methylphenylamine.
Is N-Methyl Aniline an octane booster or an octane improver? Both terms describe the same function. An octane booster or octane improver is an additive that raises the RON of gasoline to improve knock resistance. NMA is an ashless, metal-free additive of this type.
How much does an N-Methyl Aniline octane booster raise gasoline octane? The RON uplift depends on the base gasoline composition and the treat rate. NMA is known for a substantial gain at comparatively low blend ratios, but the result should always be confirmed by blend testing on your own streams.
Is N-Methyl Aniline permitted as a gasoline additive? It depends on the destination market. Some jurisdictions permit NMA within defined limits, while others restrict or prohibit it in motor fuels. Verify current fuel-quality regulations before blending or importing.
Is NMA safe for catalytic converters and oxygen sensors? NMA contains no metals and produces no metallic ash, so it avoids the deposit problems associated with metal-based antiknock agents. Compatibility should still be confirmed for your fuel specification and market.
Why does NMA turn yellow or brown? Aromatic amines oxidise slowly in contact with air and light. Colour development is normal over time and is minimised by storing in sealed containers, protected from heat and light.
What purity does PETRONAX supply? High-purity commercial grade, with batch-specific values on the Certificate of Analysis. Custom specifications can be discussed for demanding synthesis applications.
What order sizes are available? From drum quantities for R&D and small-scale production up to ISO tanks and bulk parcels for refinery-scale users. Smaller volumes can be ordered through the PETRONAX shop.
Order N-Methyl Aniline Octane Booster from PETRONAX
Whether you are a refiner looking to optimise your octane pool, a dye manufacturer protecting shade consistency, or a chemist qualifying a new intermediate supplier, PETRONAX can supply high-quality N-Methyl Aniline with dependable global delivery.
Request a quotation, download a technical datasheet, or contact the PETRONAX team for a technical consultation. We reply within 24 hours, provide technical information within 2 hours and can dispatch samples within 3 days.
Disclaimer: This article is for general information only. Product specifications, permitted applications and regulatory status vary by market and may change. Nothing here is a warranty of fitness for a particular purpose or a guarantee of regulatory compliance. Customers are responsible for verifying that their intended use complies with all applicable laws and for handling the product in accordance with the current Safety Data Sheet.