N,N-Diethyl-M-Toluidine
N,N-Diethyl-3-methylaniline (DEMT) · CAS 91-67-8
N,N-Diethyl-M-Toluidine is a coupling component with a methyl group next to its coupling site, which shifts the dyes made from it to deeper, bluer shades. Coupled with diazotised nitroanilines it gives orange-red to violet azo dyes; nitrosated and reduced, it becomes CD-2, the colour developing agent for photographic film. Chelora Dyes supplies it lot-tested with batch data and a Safety Data Sheet on every shipment, so your coupling starts from a consistent, characterised material.
Also sold as: N,N-Diethyl-3-methylaniline · N,N-Diethyl-m-toluidine · DEMT · 3-(Diethylamino)toluene
- CAS number
- 91-67-8
- Molecular formula
- C11H17N
- Molecular weight
- 163.26 g/mol
- Appearance
- Pale yellow liquid
Structure of N,N-Diethyl-M-Toluidine
Benzene ring with N(C2H5)2 and a meta CH3What N,N-Diethyl-M-Toluidine is
A colourless to pale yellow liquid tertiary amine: N,N-diethylaniline with a methyl group meta to the nitrogen. The methyl group sits beside the reactive para carbon, so everything built there — azo dyes, developers, aldehydes — carries it alongside.
Identification
Use these details when you match N,N-Diethyl-M-Toluidine against your own purchase specification.
- Product name
- N,N-Diethyl-M-Toluidine
- Chemical name
- N,N-Diethyl-3-methylaniline (N,N-Diethyl-m-toluidine)
- CAS number
- 91-67-8
- EC / EINECS
- 202-089-3
- Molecular formula
- C11H17N
- Molecular weight
- 163.26 g/mol
- Product family
- Aromatic amine intermediates
- Common end use
- Azo coupling component for dyes, CD-2 colour developer, dye intermediates
Physical and chemical behaviour
The points that decide how the material handles on your plant and in your reactions.
- Appearance
- Colourless to pale yellow liquid with an amine odour. Darkens on exposure to air and light.
- Boiling point
- About 231 °C at atmospheric pressure. Density about 0.92–0.93 g/mL at 20 °C.
- Solubility
- Practically insoluble in water. Miscible with ethanol, diethyl ether, acetone and aromatic solvents; dissolves in dilute mineral acids.
- Reactivity
- The para carbon (position 4) is strongly activated. It couples with diazonium salts to give azo dyes, and nitrosation there followed by reduction gives 4-amino-N,N-diethyl-3-methylaniline, the CD-2 developer. Vilsmeier formylation gives the corresponding benzaldehyde.
- Stability
- Stable in closed containers. 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, nitrosating agents except under controlled conditions. Combustible liquid (flash point about 104 °C).
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, which carries into dye shade and developer purity. |
| Purity | 99.0% minby GC | Sets the coupler equivalent. Lower purity means weaker dye and more unreacted diazonium salt. |
| N-Ethyl-m-toluidine | 0.5% maxmono-ethyl amine | The secondary amine couples and nitrosates differently, giving by-product dyes and N-nitroso impurities. |
| m-Toluidine | 0.1% maxfree primary amine | Diazotises in its own right and forms mixed azo by-products. |
| Isomer content | Controlledo- and p-toluidine derived | Isomeric diethyltoluidines couple at different rates and to different shades. |
| Moisture | 0.1% maxby Karl Fischer | Water interferes with Vilsmeier formylation and weighing accuracy. |
| Colour | 100 maxHazen (APHA) | A quick check on freshness; oxidised coupler gives duller dyes and darker developer. |
| Density | 0.920–0.930 g/mLat 20 °C | Confirms identity, flags gross contamination and converts volume to weight on the plant. |
Coupling to a shade standard or making CD-2? Send us your purchase specification, including purity, mono-ethyl and m-toluidine limits, isomers 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-Diethyl-M-Toluidine sits on the synthesis route
DEMT is made by ethylating m-toluidine, passing through N-ethyl-m-toluidine on the way. It is the last isolated step before coupling, nitrosation or formylation.
-
Toluene
The feedstock. Nitration with mixed acid (HNO3/H2SO4) gives nitrotoluene isomers, from which the minor meta isomer is separated.
-
m-Toluidine
Reduction of m-nitrotoluene gives m-toluidine, the primary amine with a methyl group meta to nitrogen.
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N-Ethyl-m-toluidine
The first ethyl group goes on to give N-ethyl-m-toluidine, the secondary amine.
-
N,N-Diethyl-m-toluidine
A second ethyl group completes the tertiary amine, which is distilled — the intermediate you buy.
This product -
Downstream products
Azo coupling gives disperse and specialty dyes; nitrosation and reduction give CD-2; Vilsmeier formylation gives 4-diethylamino-2-methylbenzaldehyde.
Key derivatives of N,N-Diethyl-M-Toluidine
DEMT is valued for its para carbon. Each derivative builds a new bond there, with the neighbouring methyl group carried along into the product.
CD-2 colour developer
Nitrosation para to the amine and reduction give CD-2, whose oxidised form reacts with couplers to form the image dyes in colour film processing.
- Class
- Colour developer
- Route
- Nitrosation, reduction
- Use
- Photographic
Azo disperse dyes
Coupled with diazotised nitroanilines such as para-nitroaniline or 2,6-dichloro-4-nitroaniline, it gives orange-red to rubine and violet shades depending on the diazo component.
- Class
- Monoazo disperse
- Role
- Coupler
- Use
- Polyester, acetate
4-Diethylamino-2-methylbenzaldehyde
Formylation at the para carbon gives an aldehyde used to build methine and styryl dyes and other fine chemicals.
- Class
- Aromatic aldehyde
- Route
- Vilsmeier–Haack
- Use
- Methine dyes
4-Nitroso intermediate
The 4-nitroso compound formed on nitrosation is the reactive intermediate on the way to CD-2, and a starting point for further condensation chemistry.
- Class
- C-Nitroso amine
- Route
- Nitrosation
- Use
- Intermediate
Need a related amine? N-Ethyl-M-Toluidine is its mono-ethyl precursor, used to build functionalised couplers, and N,N-Diethylaniline is the version without the methyl group. If you run several lines, they can come on the same order.
Where the chemistry leads
N,N-Diethyl-M-Toluidine is a specialist coupling component. It feeds disperse and specialty dyes and photographic chemistry, and its purity shows up in shade and developer quality.
Azo disperse dyes
As a coupler, DEMT gives deeper, bluer shades than N,N-diethylaniline with the same diazo component. Dye makers need low mono-ethyl and free m-toluidine, because each couples to its own by-product dye.
Photographic chemicals
DEMT is the precursor to CD-2, the colour developing agent whose oxidised form combines with couplers to build the dye image in colour film processing.
Methine and specialty dyes
Formylated DEMT gives 4-diethylamino-2-methylbenzaldehyde, which condenses with active methylene and heterocyclic compounds to give methine and styryl dyes.
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-Diethyl-M-Toluidine.
Purity and mono-ethyl content
N-Ethyl-m-toluidine couples and nitrosates differently, giving by-product dyes and N-nitroso impurities.
Free m-toluidine
The primary amine diazotises and couples on its own, forming mixed azo by-products.
Isomer content
Isomeric diethyltoluidines from impure toluidine feed couple at different positions and shift the shade.
Colour and moisture
Oxidised coupler gives duller dyes and darker developer; water interferes with formylation.
Tested in-house, documented in full
Consistent downstream chemistry starts with a consistent intermediate. Each lot of N,N-Diethyl-M-Toluidine 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 azo coupling, nitrosation and developer 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-Diethyl-M-Toluidine is a stable liquid in closed containers, but it is harmful 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
- Rotate stock so older lots are used first
Read the Safety Data Sheet before first use. N,N-Diethyl-M-Toluidine is classified as harmful if swallowed, in contact with skin or if inhaled, causes skin and eye irritation, and is harmful to aquatic life with long-lasting effects. It is a combustible liquid. The SDS sets out the required PPE, exposure controls, storage conditions, first-aid measures and spill response. If anything on it is unclear, ask our technical team.
How to order N,N-Diethyl-M-Toluidine
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 coupling, nitrosation or formylation process beside your current material.
Confirm supply
Once the trial clears, we schedule repeat supply to the same specification, lot after lot.
N,N-Diethyl-M-Toluidine: 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-Diethyl-M-Toluidine?
N,N-Diethyl-M-Toluidine (N,N-diethyl-3-methylaniline, DEMT, CAS 91-67-8) is a colourless to pale yellow liquid tertiary aromatic amine. It is a coupling component for azo dyes and the precursor to the photographic colour developer CD-2.
What is the CAS number and molecular formula?
The CAS number is 91-67-8. The EC (EINECS) number is 202-089-3. The molecular formula is C11H17N and the molecular weight is 163.26 g/mol.
How is N,N-Diethyl-M-Toluidine manufactured?
m-Toluidine is ethylated, with ethanol over an acid catalyst or with an ethyl halide. The reaction passes through N-ethyl-m-toluidine to the tertiary amine, which is purified by distillation.
What does the meta methyl group do?
In DEMT the methyl group sits next to the para carbon where coupling happens. In the finished azo dye it ends up beside the azo bond, which shifts absorption to longer wavelengths and gives deeper, bluer shades than N,N-diethylaniline.
What is CD-2, and how is it made from DEMT?
CD-2 is 4-amino-N,N-diethyl-3-methylaniline, usually supplied as its hydrochloride. DEMT is nitrosated at the para position and the nitroso compound is reduced to the amine. CD-2 is a colour developing agent used in colour film processing.
Which dyes are made with DEMT?
It is used as the coupling component in azo disperse and specialty dyes; paired with nitroaniline diazo components it gives orange-red, rubine and violet shades. Formylated, it gives an aldehyde for methine and styryl dyes.
Is N,N-Diethyl-M-Toluidine soluble in water?
It is practically insoluble in water. It mixes freely with ethanol, diethyl ether, acetone and aromatic solvents, and dissolves in dilute mineral acids.
How does it differ from N-Ethyl-M-Toluidine?
N-Ethyl-m-toluidine has one ethyl group and a free N–H, so it can take a second, functional substituent such as cyanoethyl or hydroxyethyl. DEMT has two ethyl groups and is used directly as a coupler or developer precursor.
Which impurities matter most?
Residual N-ethyl-m-toluidine and m-toluidine, which couple or nitrosate into by-products, and isomeric diethyltoluidines from impure toluidine feed, which shift the shade.
What purity do you supply?
Standard commercial material is supplied at a minimum purity of 99% by GC, with the actual figure for your lot on the batch test report. If you work to tighter impurity or colour limits, send your specification and we will confirm what we can supply.
What is the boiling point?
N,N-Diethyl-M-Toluidine boils at about 231 °C at atmospheric pressure, with a density of about 0.92–0.93 g/mL at 20 °C and a flash point of about 104 °C.
Is N,N-Diethyl-M-Toluidine hazardous?
Yes. It is harmful by ingestion, skin contact and inhalation, irritates skin and eyes, and is harmful 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 oxidisers, strong acids and nitrosating agents.
Why should opened drums be blanketed with nitrogen?
Like other aromatic amines, N,N-Diethyl-M-Toluidine oxidises slowly in air and light, forming coloured by-products. Blanketing part-used drums with nitrogen and keeping them closed holds the colour down, which matters for pale dyes and developer quality.
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-Diethyl-M-Toluidine 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-Ethyl-M-Toluidine or a diazo component such as 2,6-Dichloro-4-Nitroaniline, put them on the same enquiry.