3-Methyl-2-pyrrolidinone

Also known as: (R,S)-3-Methyl-pyrrolidin-2-one, 2-Pyrrolidinone, 3-methyl-, 3-Methyl-2-pyrrolidone, 3-methylpyrrolidin-2-one, alpha-Methylbutyrolactam, alpha-Methylbutyrolactame

3-Methyl-2-pyrrolidinone (CAS 2555-05-7) is a compound in the Ketones category listed in the Jingsj chemical database. It has the molecular formula C5H9NO and a molecular weight of 99.131 g/mol. Key properties include a melting point of 55ºC, a boiling point of 240.5±9.0 °C at 760 mmHg, a density of 1.0±0.1 g/cm3 and a flash point of 127.5±3.7 °C. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.

CAS No.: 2555-05-7
Jingsj CID: J-1408337-5
Molecular Formula: C₅H₉NO
Molecular Weight: 99.131 g/mol
Category: Ketones
Last updated: 8/21/2026

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Physicochemical Properties

Melting Point	55ºC
Boiling Point	240.5±9.0 °C at 760 mmHg
Density	1.0±0.1 g/cm3
Flash Point	127.5±3.7 °C
Exact Mass	99.068413
PSA	29.10000
LogP	-0.96
Vapor Pressure	0.0±0.5 mmHg at 25°C
Refractive Index	1.439

Customs & Trade Information

HS Code	2933790090
Summary	2933790090. other lactams. VAT:17.0%. Tax rebate rate:9.0%. . MFN tariff:9.0%. General tariff:20.0%

Frequently Asked Questions

What is the CAS number of 3-Methyl-2-pyrrolidinone?

The CAS number of 3-Methyl-2-pyrrolidinone is 2555-05-7.

What are the molecular formula and molecular weight of 3-Methyl-2-pyrrolidinone?

3-Methyl-2-pyrrolidinone has molecular formula C5H9NO and molecular weight 99.131 g/mol.

What are the upstream and downstream products of 3-Methyl-2-pyrrolidinone?

For 3-Methyl-2-pyrrolidinone, Upstream Products: 1-(Trimethylsilyl)pyrrolidin-2-one, iodomethane, Itaconic acid; Downstream Products: 3-Methylpyrrolidine, 1-[tert-butyl(dimethyl)silyl]-3-methylpyrrolidin-2-one, 4-amino-2-methylbutanoic acid.

Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.

Last updated: 8/21/2026

How to cite: Jingsj. "3-Methyl-2-pyrrolidinone (CAS 2555-05-7)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-1408337-5 (accessed 2026-11-09).

Data for reference only; verify product details with suppliers before purchase.