Trimethoprim
Also known as: 5-[(3,4,5-trimethoxyphenyl)methyl]pyrimidine-2,4-diamine, 5-(3,4,5-Trimethoxybenzyl)-2,4-pyrimidinediamine, 2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine, TMP, Proloprim, Trimpex, Monotrim, Triprim, Syraprim, Bactramin
Trimethoprim (CAS 738-70-5) is a compound in the Organic Compounds category listed in the Jingsj chemical database. It has the molecular formula C14H18N4O3 and a molecular weight of 290.318 g/mol. Key properties include a melting point of 199-203 °C, a boiling point of 405.2±55.0 °C at 760 mmHg, a density of 1.3±0.1 g/cm3 and a flash point of 198.8±31.5 °C. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.
- CAS No.
- 738-70-5
- Jingsj CID
- J-37853-0
- Molecular Formula
- C14H18N4O3
- Molecular Weight
- 290.318 g/mol
- Category
- Organic Compounds
- Last updated
- 8/21/2026
No offers for this compound yet.
Request a quotePhysicochemical Properties
| Melting Point | 199-203 °C |
|---|---|
| Boiling Point | 405.2±55.0 °C at 760 mmHg |
| Density | 1.3±0.1 g/cm3 |
| Flash Point | 198.8±31.5 °C |
| Exact Mass | 290.137878 |
| PSA | 105.51000 |
| LogP | 0.38 |
| Vapor Pressure | 0.0±0.9 mmHg at 25°C |
| Refractive Index | 1.600 |
| Stability | Stable. Incompatible with strong oxidizing agents, acids. |
| Additional Property | DMSO: soluble | <0.1 g/100 mL at 24 ºC |
Activity & Biological Data
| Additional Information | [1]. Laskowska, E., et al., Trimethoprim induces heat shock proteins and protein aggregation in E. coli cells. Curr Microbiol, 2003. 47(4): p. 286-9. [2]. Brogden, R.N., et al., Trimethoprim: a review of its antibacterial activity, pharmacokinetics and therapeutic use in urinary tract infections. Drugs, 1982. 23(6): p. 405-30. |
|---|
Customs & Trade Information
| HS Code | 2933599090 |
|---|---|
| Summary | 2933599090. other compounds containing a pyrimidine ring (whether or not hydrogenated) or piperazine ring in the structure. VAT:17.0%. Tax rebate rate:13.0%. . MFN tariff:6.5%. General tariff:20.0% |
Frequently Asked Questions
What is the CAS number of Trimethoprim?
The CAS number of Trimethoprim is 738-70-5.
What are the molecular formula and molecular weight of Trimethoprim?
Trimethoprim has molecular formula C14H18N4O3 and molecular weight 290.318 g/mol.
What are the upstream and downstream products of Trimethoprim?
For Trimethoprim, Upstream Products: iodomethane, 3-Anilino-2-(3,4,5-trimethoxybenzyl)acrylonitrile (mixture of cis/trans isomers), 3,4,5-Trimethoxybenzaldehyde; Downstream Products: Triethylamine hydrochloride, Talmetoprim.
Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.
Last updated:
How to cite: Jingsj. "Trimethoprim (CAS 738-70-5)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-37853-0 (accessed 2026-11-09).
Data for reference only; verify product details with suppliers before purchase.