N,N-Dimethylaniline
N,N-Dimethylaniline (DMA, Dimethylaminobenzene) · CAS 121-69-7
N,N-Dimethylaniline is the tertiary aromatic amine at the heart of the triarylmethane dye family. Its strongly activated para position condenses and couples readily, giving crystal violet, methyl violet and malachite green, as well as Michler's ketone and 4-dimethylaminobenzaldehyde. It is also a cure promoter for polyester resins and an acid-binding base in pharmaceutical synthesis. Chelora Dyes supplies it lot-tested with batch data and a Safety Data Sheet on every shipment, so your synthesis starts from a consistent, characterised material.
Also sold as: N,N-Dimethylbenzenamine · DMA · Dimethylaniline · (Dimethylamino)benzene
- CAS number
- 121-69-7
- Molecular formula
- C8H11N
- Molecular weight
- 121.18 g/mol
- Appearance
- Pale yellow liquid
Structure of N,N-Dimethylaniline
Benzene ring with a dimethylamino N(CH3)2 groupWhat N,N-Dimethylaniline is
A colourless to pale yellow liquid tertiary amine with two methyl groups on the nitrogen. The dimethylamino group makes the para position of the ring strongly nucleophilic, which is what dye, pharmaceutical and resin chemists exploit.
Identification
Use these details when you match N,N-Dimethylaniline against your own purchase specification.
- Product name
- N,N-Dimethylaniline
- Chemical name
- N,N-Dimethylaniline (N,N-Dimethylbenzenamine)
- CAS number
- 121-69-7
- EC / EINECS
- 204-493-5
- Molecular formula
- C8H11N
- Molecular weight
- 121.18 g/mol
- Product family
- Aromatic amine intermediates
- Common end use
- Triarylmethane dyes, dye and pharmaceutical intermediates, resin cure promoter
Physical and chemical behaviour
The points that decide how the material handles on your plant and in your reactions.
- Appearance
- Colourless to pale yellow oily liquid with an amine odour. Darkens to yellow-brown on exposure to air and light.
- Boiling and freezing point
- Boils at 193–194 °C. Freezes at about 2 °C, so it can solidify in cold storage or winter transport. Density about 0.956 g/mL at 25 °C.
- Solubility
- Slightly soluble in water. Miscible with ethanol, diethyl ether, acetone, chloroform and aromatic solvents; dissolves in dilute mineral acids as its salt.
- Reactivity
- A weak base. Electrophiles attack the para position: nitrosation gives 4-nitroso-N,N-dimethylaniline, azo coupling gives dimethylaminoazo dyes, phosgene gives Michler's ketone, and Vilsmeier formylation gives 4-dimethylaminobenzaldehyde. With benzoyl peroxide it forms radicals, which is how it promotes resin cure.
- Stability
- Stable in closed containers. Oxidises and darkens slowly in air and light; keep it covered, ideally under nitrogen once opened.
- Incompatibilities
- Strong oxidising agents and peroxides, strong acids, acid chlorides and anhydrides, halogens and nitrosating agents. Combustible liquid (flash point about 63 °C); decomposition releases nitrogen oxides.
Typical specification
Every lot is tested in-house against its specification before dispatch, and the results travel with the shipment. If you work to a tighter window on any line below, send it to us and we will confirm whether we can supply to it.
| Parameter | Indicative value | Why it matters to you |
|---|---|---|
| Appearance | Clear, colourless to pale yellow liquid | A darker colour points to oxidation in storage or production, and it carries into dye shade and clear resins. |
| Purity | 99.5% minby GC | Sets the active content for condensations and couplings. Lower purity means lower dye strength and yield. |
| N-Methylaniline | 0.2% maxunder-methylated amine | The secondary amine forms N-nitroso and N-acyl by-products, consumes reagents and gives off-shade dyes. |
| Aniline | 0.05% maxfree primary amine | Diazotises and couples in its own right, adding impurities to dye and pharmaceutical products. |
| Moisture | 0.1% maxby Karl Fischer | Water destroys phosgene, acid chlorides and Vilsmeier reagent, and upsets resin cure. |
| Colour | 50 maxHazen (APHA) | A quick check on freshness; colour carries into pale dyes and clear castings. |
| Density | 0.954–0.958 g/mLat 20 °C | Confirms identity, flags gross contamination and converts volume to weight on the plant. |
| Distillation range | 192–195 °C95% distilled | A narrow range confirms low levels of lighter and heavier impurities. |
Working to a dye-house or pharmaceutical specification? Send us your purchase specification, including purity, N-methylaniline and aniline limits, moisture and colour, through the contact page. We will confirm what we can supply, and send a sample with its test data so you can run it beside your current material.
Where N,N-Dimethylaniline sits on the synthesis route
DMA is made by exhaustive methylation of aniline with methanol over an acid catalyst. It is the last isolated step before condensation, coupling or formylation.
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Benzene
The feedstock. Nitration with mixed acid (HNO3/H2SO4) gives nitrobenzene.
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Aniline
Catalytic hydrogenation of nitrobenzene gives aniline, the parent primary amine.
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N,N-Dimethylaniline
Aniline is alkylated with methanol (or dimethyl ether) over an acid catalyst. N-Methylaniline forms along the way and is driven on to the tertiary amine, which is distilled — the intermediate you buy.
This product -
Para-substitution
The activated para position reacts with carbonyl compounds, diazonium salts, nitrosating agents and Vilsmeier reagent.
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Downstream products
Crystal violet and methyl violet, malachite green (with benzaldehyde), Michler's ketone, 4-dimethylaminobenzaldehyde and dimethylaminoazo dyes.
Key derivatives of N,N-Dimethylaniline
DMA reaches its customers through the para position. Each derivative adds a carbon or nitrogen electrophile opposite the dimethylamino group.
Crystal violet
A deep violet triarylmethane dye built from three DMA units around one central carbon. Used as a biological stain, in inks and as the basis of methyl violet grades.
- Class
- Cationic triarylmethane
- Route
- Condensation, oxidation
- Use
- Stains, inks
Malachite green
Two molecules of DMA condense with benzaldehyde to the leuco base, which is oxidised to the green dye used for paper, leather and silk.
- Class
- Cationic triarylmethane
- Partner
- Benzaldehyde
- Use
- Paper, leather
Michler's ketone
Made from DMA and phosgene. An intermediate for triarylmethane dyes such as crystal violet, and a photosensitiser.
- CAS No.
- 90-94-8
- Route
- Phosgene acylation
- Use
- Dye intermediate
4-Dimethylaminobenzaldehyde
DMA formylated with DMF and phosphorus oxychloride gives Ehrlich's reagent, used in analytical tests and as a dye and pharmaceutical intermediate.
- CAS No.
- 100-10-7
- Route
- Vilsmeier–Haack
- Use
- Reagents, dyes
Need a related amine? N,N-Diethylaniline is the ethyl analogue behind brilliant green and the patent blues, and N,N,4-Trimethylaniline (N,N-dimethyl-p-toluidine) is the para-methyl analogue used as a faster peroxide accelerator. If you run several lines, they can come on the same order.
Where the chemistry leads
N,N-Dimethylaniline is a workhorse tertiary amine. It feeds dye, pharmaceutical and resin production, and its purity shows up in the shade, yield and cure behaviour of every downstream product.
Triarylmethane and azo dyes
DMA is the classic building block of crystal violet, methyl violet and malachite green, and a coupler for dimethylaminoazo dyes. Dye makers look for low N-methylaniline and aniline, because both give by-products that dull the shade.
Pharmaceutical synthesis
DMA is used as an acid-binding base in acylation steps, including some processes for semi-synthetic beta-lactam antibiotics, and as a source of dimethylamino-substituted aromatic intermediates.
Resins and composites
With benzoyl peroxide, DMA promotes the room-temperature cure of unsaturated polyester and vinyl ester resins used in composites, putties and castings.
What buyers check before they switch supplier
Four parameters explain most of the yield, shade and purity complaints when a manufacturer changes its source of N,N-Dimethylaniline.
Purity and N-methylaniline
The secondary amine reacts where DMA does not, giving N-nitroso and N-acyl by-products and consuming reagents.
Free aniline
Aniline diazotises and couples on its own, adding coloured impurities to dyes and unwanted amines to pharmaceutical products.
Moisture
Water destroys phosgene, acid chlorides and Vilsmeier reagent, and changes gel time in resin systems.
Colour and storage history
Oxidised, darkened material carries colour into pale dyes and clear resins. Hazen colour is the quick check.
Tested in-house, documented in full
Consistent downstream chemistry starts with a consistent intermediate. Each lot of N,N-Dimethylaniline is checked against its specification before it leaves, and the result goes out with the material so your goods-in team can release it without a second test.
- Each lot tested against the product specification before dispatch
- Batch test report supplied with every shipment
- Safety Data Sheet supplied with the first order and on request
- Technical and specification sheets available before you order
- Samples sent with their own test data, so a trial compares like with like
- Chemists familiar with tertiary amine condensation, coupling and cure chemistry, available to discuss results
What arrives with the material
Enough paperwork for your goods-in and quality teams to release the lot without retesting it.
- Batch test report
- The tested figures for the lot you have received, set against the specification.
- Safety Data Sheet
- Classification, protective equipment, storage conditions, first aid and spill response.
- Specification sheet
- The parameters and limits we supply against, available before you place the order.
- Sample test data
- Sent with every trial sample, so a comparison against your current material starts from the same numbers.
Packing, storage and handling
N,N-Dimethylaniline is a stable liquid in closed containers, but it is toxic, combustible and absorbed through the skin. Follow all guidance in the Safety Data Sheet for protective equipment and exposure control.
How it ships
- Supplied in sealed HDPE or lined steel drums, filled to leave headspace for expansion
- IBCs and bulk loads can be discussed where your process suits larger volumes
- Every container carries the product name, lot number and hazard labelling
- Pack size can be matched to your batch charge to minimise part-opened containers
- Shipped with its batch test report and Safety Data Sheet
Storing and handling on site
- Store in a cool, dry, well-ventilated area, away from direct sunlight and sources of ignition
- Keep containers tightly closed; once opened, blanket with nitrogen to slow darkening by air oxidation
- Store on bunded floors or in drip trays and transfer through closed lines or with local exhaust ventilation
- Wear the protective equipment specified in the SDS — the liquid is absorbed through intact skin
- Keep apart from peroxides, oxidising agents, strong acids and nitrosating agents; it freezes at about 2 °C, so thaw gently if it solidifies
- Rotate stock so older lots are used first
Read the Safety Data Sheet before first use. N,N-Dimethylaniline is classified as toxic if swallowed, in contact with skin or if inhaled, is suspected of causing cancer, and is toxic to aquatic life with long-lasting effects. It is readily absorbed through the skin and can cause methaemoglobinaemia. It is a combustible liquid. The SDS sets out the required PPE, exposure limits, storage conditions, first-aid measures and spill response. If anything on it is unclear, ask our technical team.
How to order N,N-Dimethylaniline
Start with a sample, move to scheduled supply. Four steps from first enquiry to a delivery pattern that matches your production plan.
Send your requirement
Product name, grade or specification, quantity, packing and delivery location, through the contact page.
Get the paperwork
We come back with the specification sheet, the Safety Data Sheet and a quote against your quantity and packing.
Run a sample
A sample with its test data, so you can run it through your condensation, coupling or curing process beside your current material.
Confirm supply
Once the trial clears, we schedule repeat supply to the same specification, lot after lot.
N,N-Dimethylaniline: frequently asked questions
What buyers, chemists and plant teams ask us most about this product. For anything else, get in touch.
What is N,N-Dimethylaniline?
N,N-Dimethylaniline (DMA, CAS 121-69-7) is a colourless to pale yellow liquid tertiary aromatic amine: aniline with two methyl groups on the nitrogen. It is a building block for triarylmethane dyes, a coupling component, a resin cure promoter and an acid-binding base.
What is the CAS number and molecular formula?
The CAS number is 121-69-7. The EC (EINECS) number is 204-493-5. The molecular formula is C8H11N and the molecular weight is 121.18 g/mol.
How is N,N-Dimethylaniline manufactured?
Aniline is alkylated with methanol, or dimethyl ether, over an acid catalyst in the liquid or vapour phase. The reaction passes through N-methylaniline to the tertiary amine, which is purified by distillation.
Why is the para position so reactive?
The nitrogen's lone pair feeds electron density into the ring, especially at the ortho and para carbons. The two methyl groups crowd the ortho positions, so electrophiles such as diazonium salts, nitrosating agents and carbonyl compounds attack the para carbon.
Which dyes are made from DMA?
Crystal violet, methyl violet and malachite green are the best-known triarylmethane dyes made from it. DMA is also a coupling component for dimethylaminoazo dyes and the starting point for Michler's ketone and 4-dimethylaminobenzaldehyde.
How is crystal violet made from DMA?
One route condenses Michler's ketone, itself made from DMA and phosgene, with a third molecule of DMA in the presence of phosphorus oxychloride. Another builds the central carbon from formaldehyde and oxidises the resulting leuco base to the dye.
What is Michler's ketone?
Michler's ketone, 4,4'-bis(dimethylamino)benzophenone (CAS 90-94-8), is made by reacting DMA with phosgene. It is an intermediate for triarylmethane dyes and is also used as a photosensitiser.
Is N,N-Dimethylaniline soluble in water?
Only slightly. It mixes freely with ethanol, diethyl ether, acetone, chloroform and aromatic solvents, and dissolves in dilute mineral acids as its salt.
How is DMA used in resin curing?
DMA reacts with benzoyl peroxide at room temperature to generate radicals, which start the cure of unsaturated polyester and vinyl ester resins. It is added to the resin as a promoter, with the peroxide added just before use.
How is DMA used in pharmaceutical manufacturing?
It serves as an acid-binding base in acylation reactions, including some processes for semi-synthetic beta-lactam antibiotics, and as a source of dimethylamino-substituted aromatic intermediates.
How does it differ from N,N-Diethylaniline?
N,N-Diethylaniline carries ethyl rather than methyl groups on the nitrogen. It gives brighter, bluer triarylmethane dyes such as brilliant green and the patent blues, and is less volatile, with a boiling point of about 217 °C.
What purity do you supply?
Standard commercial material is supplied at a minimum purity of 99.5% by GC, with the actual figure for your lot on the batch test report. If you work to tighter limits on N-methylaniline, aniline or colour, send your specification and we will confirm what we can supply.
What are the boiling and freezing points, and why do they matter?
DMA boils at 193–194 °C and freezes at about 2 °C. The low freezing point means drums can solidify in cold weather; they should be thawed gently in a warm room, never with direct heat.
Is N,N-Dimethylaniline hazardous?
Yes. It is toxic by ingestion, skin contact and inhalation, is suspected of causing cancer, can cause methaemoglobinaemia and is toxic to aquatic life. It is also a combustible liquid. Handle it with the controls and protective equipment set out in the Safety Data Sheet.
How is it packed and stored?
It ships in sealed HDPE or lined steel drums, labelled with the product name, lot number and hazard information. Store it cool, ventilated, away from light and ignition sources, and apart from peroxides, oxidisers and strong acids.
Can I get a sample, and is there a minimum order?
Yes to samples, sent with their test data so a trial compares like with like. Order quantities depend on the packing, so tell us the volume you expect through the contact page and we will confirm what is practical.
Tell us the grade and quantity of N,N-Dimethylaniline you need
Send your specification, the quantity and where it ships to, and our technical team will come back with the specification sheet, a quote and a sample plan. If you also buy N,N-Diethylaniline or N,N,4-Trimethylaniline, put them on the same enquiry.