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Antibiotics and anti-infectives

Trimethoprim

Also known as Proloprim, Trimpex, 2,4-Diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine

CAS 738-70-5Formula C14H18N4O3Molar mass 290.32 g/molEC 212-006-2
GHS signal word: Danger. Pictograms: Harmful or irritant, Serious health hazard, Hazardous to the environment 121 suppliers listed Drug substance
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Trimethoprim chemical structure, C14H18N4O3, CAS 738-70-5
2D chemical structure

Key facts

What buyers check first

All properties
Appearance
White to cream, crystalline powder
Melting point
198.9 to 202.8
Solubility
Very slightly soluble in water and slightly soluble in alcohol.
HS code
293359
Category
Antibiotics and anti-infectives
UN number
UN 2811
Illustrative photo, off-white crystalline powder with an amber glass bottle on a laboratory bench
Typical packagingIllustrative packaging image, not the actual product

What is Trimethoprim?

Plain description, key identifiers and synonyms

Trimethoprim is an aminopyrimidine antibiotic whose structure consists of pyrimidine 2,4-diamine and 1,2,3-trimethoxybenzene moieties linked by a methylene bridge. It has a role as a diuretic, a xenobiotic, an antibacterial drug, an EC 1.5.1.3 (dihydrofolate reductase) inhibitor, an environmental contaminant and a drug allergen. It is an aminopyrimidine and a member of methoxybenzenes.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
5-[(3,4,5-trimethoxyphenyl)methyl]pyrimidine-2,4-diamine
CAS number
738-70-5 CAS number cross-checked
EC number
212-006-2
Molecular formula
C14H18N4O3
UNII
AN164J8Y0X
MDL number
MFCD00036761
InChIKey
IEDVJHCEMCRBQM-UHFFFAOYSA-N
InChI
InChI=1S/C14H18N4O3/c1-19-10-5-8(6-11(20-2)12(10)21-3)4-9-7-17-14(16)18-13(9)15/h5-7H,4H2,1-3H3,(H4,15,16,17,18)
SMILES (canonical and isomeric)
COC1=CC(=CC(=C1OC)OC)CC2=CN=C(N=C2N)N

Synonyms

  • Proloprim
  • Trimpex
  • 2,4-Diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine
  • Trimetoprim
  • Monotrim
  • Trimopan
  • Wellcoprim
  • Syraprim
  • Monoprim
  • Uretrim
  • Trimethoprime
  • Trimethoprimum
  • 5-[(3,4,5-trimethoxyphenyl)methyl]pyrimidine-2,4-diamine
  • Trimetoprima
  • Tiempe
  • Trimpex 200
  • BW 56-72
  • NIH 204
  • Trimogal
  • Infectotrimet
  • 2,4-Pyrimidinediamine, 5-[(3,4,5-trimethoxyphenyl)methyl]-
  • 5-(3,4,5-Trimethoxybenzyl)-2,4-diaminopyrimidine
  • 5-[(3,4,5-Trimethoxyphenyl)methyl]-2,4-pyrimidinediamine
  • 2,4-Pyrimidinediamine, 5-((3,4,5-trimethoxyphenyl)methyl)-
  • Pyrimidine, 2,4-diamino-5-(3,4,5-trimethoxybenzyl)-
Show all 38 synonyms
  • 5-((3,4,5-Trimethoxyphenyl)methyl)-2,4-pyrimidinediamine
  • 5-((3,4,5-trimethoxyphenyl)methyl)pyrimidine-2,4-diamine
  • Ledatrim
  • Proloprin
  • Triprimix 200
  • Monotrimin
  • 5-(3,4,5-trimethoxybenzyl)pyrimidine-2,4-diamine
  • Triprim
  • Streptoplus
  • Anitrim
  • Bactoprim
  • Espectrin
  • Resprim

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

Appearance
White to cream, crystalline powderexp.
Odour
Odorlessexp.
Taste
Bitterexp.
Melting point
198.9 to 202.8exp.
Solubility
Very slightly soluble in water and slightly soluble in alcohol.exp.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
290.32 g/molcalc.
Exact mass
290.1379 Dacalc.
LogP (octanol/water)
1.26calc.
Topological polar surface area
105.5 Ųcalc.
Hydrogen bond donors
2calc.
Hydrogen bond acceptors
7calc.
Rotatable bonds
5calc.
Heavy atoms
21calc.
Rings
2calc.
Aromatic rings
2calc.
Fraction sp3 carbons
0.29calc.
Formal charge
0calc.
Stereocentres
0calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Murcko scaffold

The ring system that remains when every side chain is removed

Murcko scaffold of this chemical, c1ccc(Cc2cncnc2)cc1

c1ccc(Cc2cncnc2)cc1

2 rings, 13 atoms, the 5-Benzylpyrimidine ring system.

375 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Danger
GHS07: Harmful or irritant
Harmful or irritant
GHS08: Serious health hazard
Serious health hazard
GHS09: Hazardous to the environment
Hazardous to the environment

Hazard statements

  • H302Harmful if swallowed.
  • H361Suspected of damaging fertility or the unborn child.
  • H372Causes damage to organs through prolonged or repeated exposure.
  • H411Toxic to aquatic life with long lasting effects.
Precautionary statements (13)
  • P203Obtain, read and follow all safety instructions before use.
  • P260Do not breathe dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P270Do not eat, drink or smoke when using this product.
  • P273Avoid release to the environment.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P301 + P317If swallowed: Get medical help.
  • P318If exposed or concerned, get medical advice.
  • P319Get medical help if you feel unwell.
  • P330Rinse mouth.
  • P391Collect spillage.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.
UN number
UN 2811

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Full safety data and first aid

Trimethoprim suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 121 suppliers
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Where suppliers are based

121 suppliers in 17 countries

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Trimethoprim price

Indicative price range per kg from live supplier offers

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Uses and applications

What the substance is used for, by industry and function

Veterinary antimicrobial agent.

Has a broad spectrum of antimicrobial activity and extends the spectrum of sulfamethoxazole to include many urinary and systemic pathogens untreatable by this sulfa drug alone.

Veterinary medication:.

Use classes: Pharmaceuticals, Animal Drugs.

Pharmacological actions

  • Anti-Dyskinesia Agents
  • Anti-Infective Agents, Urinary
  • Antimalarials
  • Cytochrome P-450 CYP2C8 Inhibitors
  • Folic Acid Antagonists

Roles

  • anti-HIV agent
  • anti-anaemic agent
  • antibacterial agent
  • antibacterial drug
  • antifibrotic agent
  • antifungal agent
  • antiinfective agent
  • antimalarial
  • antimicrobial agent
  • antimicrobial drug
  • antimycobacterial drug
  • antineoplastic agent
  • antiprotozoal drug
  • antitubercular agent
  • dermatologic drug
  • diuretic
  • drug allergen
  • environmental contaminant
  • hypoglycemic agent
  • ophthalmology drug
  • pharmaceutical
  • protective agent
  • renoprotective agent
  • xenobiotic

Functional uses

  • Pharmaceutical

Pharmacology

Trimethoprim is a Dihydrofolate Reductase Inhibitor Antibacterial. The mechanism of action of trimethoprim is as a Dihydrofolate Reductase Inhibitor, and Cytochrome P450 2C8 Inhibitor, and Organic Cation Transporter 2 Inhibitor.

How it is made

Prepn from guanidine and beta-ethoxy-3,4,5-trimethoxybenzylbenzalnitrile

Trimethoprim (is a) drug that (is) made from vanillin.

Regulatory status

Inventories, regulations and trade controls that list this substance

Health and food

  • Active ingredient in FDA approved drug labels

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Trimethoprim is traded under.

HS 2933.59Indicative HS code

Compounds containing a pyrimidine ring (whether or not hydrogenated) or piperazine ring, other

World exports in 2024
$18.4B
+10.5% vs 2023, imports $24.8B
2019 to 2024
Top exporters
  1. Ireland43.6%
  2. Switzerland * partner reported26.3%
  3. China7.9%
Top importers
  1. Slovenia30.3%
  2. United States30.1%
  3. Germany15.3%

* Partner reported figures, a lower bound.

Reported customs values in USD, not prices.Full trade data

The HS code shown for Trimethoprim is indicative (it was assigned by structure rules). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about Trimethoprim, based on the data on this page

What is Trimethoprim?

Trimethoprim is an aminopyrimidine antibiotic whose structure consists of pyrimidine 2,4-diamine and 1,2,3-trimethoxybenzene moieties linked by a methylene bridge.

What is the CAS number of Trimethoprim?

The CAS registry number of Trimethoprim is 738-70-5.

What is the molecular formula and weight of Trimethoprim?

The molecular formula of Trimethoprim is C14H18N4O3 and its molar mass is 290.32 g/mol.

What is Trimethoprim used for?

Veterinary antimicrobial agent. Has a broad spectrum of antimicrobial activity and extends the spectrum of sulfamethoxazole to include many urinary and systemic pathogens untreatable by this sulfa drug alone. Veterinary medication:. Use classes: Pharmaceuticals, Animal Drugs.

Is Trimethoprim hazardous?

Trimethoprim carries the GHS signal word "Danger". Main hazards: harmful if swallowed, suspected of damaging fertility or the unborn child, causes damage to organs through prolonged or repeated exposure. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Trimethoprim?

Trimethoprim is usually classified under HS code 293359 (Compounds containing a pyrimidine ring (whether or not hydrogenated) or piperazine ring…). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Trimethoprim?

CompoundList lists 121 suppliers of Trimethoprim in United States, China, India, Germany and 13 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy Trimethoprim in India?

9 suppliers in India list Trimethoprim on CompoundList. Filter the suppliers list by country and send a request to compare prices, grades and delivery times.

What is the price of Trimethoprim?

Suppliers quote Trimethoprim on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Trimethoprim

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Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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