3-Mercaptoisobutyric acid

Also known as: 3-Mercapto-2-methylpropanoic acid, 3-Mercapto-2-methylpropionic acid, Captopril EP Impurity C, Captopril impurity C, 2-Methyl-3-sulfanylpropanoic acid, 2-(Mercaptomethyl)propanoic acid, Propanoic acid, 3-mercapto-2-methyl-, (2RS)-2-Methyl-3-sulphanylpropanoic acid

3-Mercaptoisobutyric acid (CAS 26473-47-2) is a compound in the Organic Acids category listed in the Jingsj chemical database. It has the molecular formula C4H8O2S and a molecular weight of 120.170 g/mol. Key properties include a boiling point of 232.5±23.0 °C at 760 mmHg, a density of 1.2±0.1 g/cm3 and a flash point of 94.4±22.6 °C. It is classified under GHS with signal word Warning and hazard statements H315 — Causes skin irritation and H319 — Causes serious eye irritation. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.

CAS No.: 26473-47-2
Jingsj CID: J-3947-4
Molecular Formula: C₄H₈O₂S
Molecular Weight: 120.170 g/mol
Category: Organic Acids
Last updated: 8/21/2026

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Physicochemical Properties

Boiling Point	232.5±23.0 °C at 760 mmHg
Density	1.2±0.1 g/cm3
Flash Point	94.4±22.6 °C
Exact Mass	120.024498
PSA	76.10000
LogP	0.78
Vapor Pressure	0.0±1.0 mmHg at 25°C
Refractive Index	1.491

GHS Safety & Compliance

IrritantSignal word: Warning

H315 — Causes skin irritation
H319 — Causes serious eye irritation

Activity & Biological Data

Additional Information	[1]. ANCA GABRIELA CÂRJE, et al. HPLC-UV METHOD APPROACH FOR THE ANALYSIS AND IMPURITY PROFILING OF CAPTOPRIL. [2]. Afrin S, et al. Eritadenine from Edible Mushrooms Inhibits Activity of Angiotensin Converting Enzyme in Vitro. J Agric Food Chem. 2016;64(11):2263-2268. [3]. Esmaeili S, et al. Captopril/enalapril inhibit promiscuous esterase activity of carbonic anhydrase at micromolar concentrations: An in vitro study. Chem Biol Interact. 2017;265:24-35.

Additional Information

[1]. ANCA GABRIELA CÂRJE, et al. HPLC-UV METHOD APPROACH FOR THE ANALYSIS AND IMPURITY PROFILING OF CAPTOPRIL. [2]. Afrin S, et al. Eritadenine from Edible Mushrooms Inhibits Activity of Angiotensin Converting Enzyme in Vitro. J Agric Food Chem. 2016;64(11):2263-2268. [3]. Esmaeili S, et al. Captopril/enalapril inhibit promiscuous esterase activity of carbonic anhydrase at micromolar concentrations: An in vitro study. Chem Biol Interact. 2017;265:24-35.

Customs & Trade Information

HS Code	2930909090
Summary	2930909090. other organo-sulphur compounds. VAT:17.0%. Tax rebate rate:13.0%. . MFN tariff:6.5%. General tariff:30.0%

Frequently Asked Questions

What is the CAS number of 3-Mercaptoisobutyric acid?

The CAS number of 3-Mercaptoisobutyric acid is 26473-47-2.

What are the molecular formula and molecular weight of 3-Mercaptoisobutyric acid?

3-Mercaptoisobutyric acid has molecular formula C4H8O2S and molecular weight 120.170 g/mol.

Is 3-Mercaptoisobutyric acid hazardous?

3-Mercaptoisobutyric acid has GHS signal word Warning and hazard statements H315 — Causes skin irritation; H319 — Causes serious eye irritation.

What are the upstream and downstream products of 3-Mercaptoisobutyric acid?

For 3-Mercaptoisobutyric acid, Upstream Products: Methacrylic acid, 3-chloro-2-methylpropanoic acid, Water; Downstream Products: (S)-(-)-3-(Acetylthio)-2-methylpropionic acid, 2-methyl-3-(methylthio)propanoic 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-Mercaptoisobutyric acid (CAS 26473-47-2)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-3947-4 (accessed 2026-11-09).

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