![Molecular structure of 2-Methylthieno[2,3-d]pyrimidin-4(3H)-one (CAS 21582-51-4)](/images/chem_structures_svg/152/21582-51-4.svg)
2-Methylthieno[2,3-d]pyrimidin-4(3H)-one
Also known as: 2-Methyl-3,4-dihydro-4-oxothieno[2,3-d]pyrimidine, 2-Methyl-3H-thieno[2,3-d]pyrimidin-4-one, 2-Methyl-4-oxo-3,4-dihydro-thieno<2,3-d>pyrimidin, 2-Methylthieno[2,3-d]pyrimidin-4-ol, Thieno[2,3-d]pyrimidin-4(3H)-one, 2-methyl-
2-Methylthieno[2,3-d]pyrimidin-4(3H)-one (CAS 21582-51-4) is a compound in the Pharma Intermediates category listed in the Jingsj chemical database. It has the molecular formula C7H6N2OS and a molecular weight of 166.200 g/mol. Key properties include a melting point of 204-206℃, a boiling point of 406.7±33.0 °C at 760 mmHg, a density of 1.5±0.1 g/cm3 and a flash point of 199.8±25.4 °C. It is classified under GHS with signal word Warning and hazard statements H302 — Harmful if swallowed. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.
- CAS No.
- 21582-51-4
- Jingsj CID
- J-1013505-4
- Molecular Formula
- C7H6N2OS
- Molecular Weight
- 166.200 g/mol
- Category
- Pharma Intermediates
- Last updated
- 8/21/2026
No offers for this compound yet.
Request a quotePhysicochemical Properties
| Melting Point | 204-206℃ |
|---|---|
| Boiling Point | 406.7±33.0 °C at 760 mmHg |
| Density | 1.5±0.1 g/cm3 |
| Flash Point | 199.8±25.4 °C |
| Exact Mass | 166.020081 |
| PSA | 73.99000 |
| LogP | 0.38 |
| Vapor Pressure | 0.0±0.9 mmHg at 25°C |
| Refractive Index | 1.753 |
GHS Safety & Compliance
- H302 — Harmful if swallowed
Customs & Trade Information
| HS Code | 2934999090 |
|---|---|
| Summary | 2934999090. other heterocyclic compounds. 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 2-Methylthieno[2,3-d]pyrimidin-4(3H)-one?
The CAS number of 2-Methylthieno[2,3-d]pyrimidin-4(3H)-one is 21582-51-4.
What are the molecular formula and molecular weight of 2-Methylthieno[2,3-d]pyrimidin-4(3H)-one?
2-Methylthieno[2,3-d]pyrimidin-4(3H)-one has molecular formula C7H6N2OS and molecular weight 166.200 g/mol.
Is 2-Methylthieno[2,3-d]pyrimidin-4(3H)-one hazardous?
2-Methylthieno[2,3-d]pyrimidin-4(3H)-one has GHS signal word Warning and hazard statements H302 — Harmful if swallowed.
What are the upstream and downstream products of 2-Methylthieno[2,3-d]pyrimidin-4(3H)-one?
For 2-Methylthieno[2,3-d]pyrimidin-4(3H)-one, Upstream Products: Ethyl 2-aminothiophene-3-carboxylate, Acetonitrile, 2-Aminothiophene-3-carboxamide; Downstream Products: 4-Chloro-2-methylthieno[2,3-d]pyrimidine, 2-Methylthieno[2,3-d]pyrimidine.
Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.
Last updated:
How to cite: Jingsj. "2-Methylthieno[2,3-d]pyrimidin-4(3H)-one (CAS 21582-51-4)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-1013505-4 (accessed 2026-11-09).
Data for reference only; verify product details with suppliers before purchase.