isatin

Also known as: 2,3-Diketoindoline, 2,3-Diketoindoline Indole-2,3-dione 2,3-Indolinedione, 2,3-Dioxo-2,3-dihydroindole, 2,3-Dioxoindoline, 2,3-INDOLEDIONE, 2,3-Indolinedione, 2,3-KETOINDOLINE, 2,3-dihydro-1H-indol-2,3-dione, 2-methopropan-1-ol, 2H-Indol-2-one, 3-hydroxy-, 3-Hydroxy-2H-indol-2-one, 3-hydroxy-2-oxoindole, 5-21-10-00221 (Beilstein Handbook Reference), EINECS 202-077-8, IRSOGLADINEMALEATE, ISATIC ANHYDRIDE, ISATIN / 2,3-INDOLINEDIONE, ISATIN, PHARMACEUTICAL GRADE, ISATIN, TECHNICAL GRADE, Indolequinone

isatin (CAS 91-56-5) is a compound in the Organic Compounds category listed in the Jingsj chemical database. It has the molecular formula C8H5NO2 and a molecular weight of 147.131 g/mol. Key properties include a melting point of 193-195 °C (dec.)(lit.), a boiling point of 360.3±52.0 °C at 760 mmHg, a density of 1.4±0.1 g/cm3 and a flash point of 171.7±30.7 °C. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.

CAS No.: 91-56-5
Jingsj CID: J-35300-1
Molecular Formula: C₈H₅NO₂
Molecular Weight: 147.131 g/mol
Category: Organic Compounds
Last updated: 8/21/2026

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Physicochemical Properties

Melting Point	193-195 °C (dec.)(lit.)
Boiling Point	360.3±52.0 °C at 760 mmHg
Density	1.4±0.1 g/cm3
Flash Point	171.7±30.7 °C
Exact Mass	147.032028
PSA	46.17000
LogP	-0.17
Vapor Pressure	0.0±1.8 mmHg at 25°C
Refractive Index	1.679

Activity & Biological Data

Target	IC50: 3 μM (MAO B)[1]
Additional Information	[1]. Glover V, et al. Isatin: Identity with the Purified Endogenous Monoamine Oxidase Inhibitor Tribulin. Journal of Neurochemistry, 51(2), 656–659. [2]. Igosheva N, et al. Isatin, an endogenous monoamine oxidase inhibitor, triggers a dose- and time-dependent switch from apoptosis to necrosis in human neuroblastoma cells. Neurochem Int. 2005 Aug;47(3):216-24. [3]. McIntyre IM, et al. Serotonergic effects of isatin: an endogenous MAO inhibitor related to tribulin. J Neural Transm Gen Sect. 1990;79(1-2):35-40.

Target

IC50: 3 μM (MAO B)[1]

Additional Information

[1]. Glover V, et al. Isatin: Identity with the Purified Endogenous Monoamine Oxidase Inhibitor Tribulin. Journal of Neurochemistry, 51(2), 656–659. [2]. Igosheva N, et al. Isatin, an endogenous monoamine oxidase inhibitor, triggers a dose- and time-dependent switch from apoptosis to necrosis in human neuroblastoma cells. Neurochem Int. 2005 Aug;47(3):216-24. [3]. McIntyre IM, et al. Serotonergic effects of isatin: an endogenous MAO inhibitor related to tribulin. J Neural Transm Gen Sect. 1990;79(1-2):35-40.

Customs & Trade Information

HS Code	2933990090
Summary	2933990090. heterocyclic compounds with nitrogen hetero-atom(s) only. 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 isatin?

The CAS number of isatin is 91-56-5.

What are the molecular formula and molecular weight of isatin?

isatin has molecular formula C8H5NO2 and molecular weight 147.131 g/mol.

What are the upstream and downstream products of isatin?

For isatin, Upstream Products: Chloral hydrate, Indole, Indole-3-carboxaldehyde; Downstream Products: 2-Amino-N-butylbenzamide, 5-(Trifluoromethyl)isatin, 2-(thiophen-2-yl)quinoline-4-carboxylic 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. "isatin (CAS 91-56-5)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-35300-1 (accessed 2026-11-07).

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