Indole-5-Carboxylic Acid CAS#1670-81-1 Product Description
Indole-5-Carboxylic Acid (CAS No. 1670-81-1) is an important indole derivative and versatile organic synthesis building block. It features an indole ring structure with a carboxylic acid functional group at the 5-position, making it a useful starting material for the preparation of various heterocyclic compounds and functionalized indole derivatives.
With its reactive carboxylic acid group and indole-based structure, Indole-5-Carboxylic Acid is widely used in organic synthesis, medicinal chemistry research, pharmaceutical intermediate development, and the preparation of biologically active compounds.
It can be utilized in the synthesis of indole derivatives, amide compounds, indirubin derivatives, and other nitrogen-containing heterocyclic molecules. It is also used in fluorescence spectroscopy research and the electrochemical preparation of poly(indole-5-carboxylic acid) films.
Indole-5-Carboxylic Acid is suitable for laboratory research, chemical synthesis, and professional industrial applications where high-quality indole building blocks are required.

Indole-5-Carboxylic Acid CAS#1670-81-1 Chemical Properties
| Melting point | 211-213 °C (lit.) |
| Boiling point | 287.44°C (rough estimate) |
| density | 1.2480 (rough estimate) |
| refractive index | 1.5050 (estimate) |
| storage temp. | Keep in dark place,Sealed in dry,Room Temperature |
| solubility | Soluble in ethanol (50 mg/ml), dimethyl sulfoxide and methanol. |
| pka | 4.40±0.30(Predicted) |
| form | Powder |
| color | Light beige to yellow |
| BRN | 124391 |
| InChIKey | IENZCGNHSIMFJE-UHFFFAOYSA-N |
| CAS DataBase Reference | 1670-81-1(CAS DataBase Reference) |
Indole-5-Carboxylic Acid CAS#1670-81-1 Safety Information
| Hazard Codes | Xn,Xi |
| Risk Statements | 36/37/38-21/22 |
| Safety Statements | 22-24/25-36/37/39-26 |
| WGK Germany | 3 |
| HazardClass | IRRITANT |
| HS Code | 29339990 |
Indole-5-Carboxylic Acid CAS#1670-81-1 Product Application
1. Pharmaceutical Intermediates
Used as an important building block in pharmaceutical intermediate synthesis.
Applied in the development of indole-based pharmaceutical compounds.
Used in medicinal chemistry research and drug discovery.
Serves as a starting material for the synthesis of biologically active molecules.
2. Indole Derivatives Synthesis
Used in the synthesis of various indole derivatives.
Applied in the preparation of functionalized indole compounds.
Used to develop structurally modified indole-based molecules.
Serves as a building block for indole-containing heterocyclic compounds.
3. Medicinal Chemistry Research
Used in the synthesis and structural modification of potential bioactive compounds.
Applied in the research of enzyme inhibitors and receptor-targeting molecules.
Used in the development of novel compounds for pharmaceutical research.
Supports research into indole-based compounds with potential biological activities.
4. Organic Synthesis
Used as a versatile building block in organic synthesis.
Applied in the preparation of amides and other carboxylic acid derivatives.
Used in the synthesis of nitrogen-containing heterocyclic compounds.
Applied in the development of complex organic molecules.
5. Heterocyclic Compound Synthesis
Used in the synthesis of nitrogen-containing heterocyclic compounds.
Serves as a precursor for various functionalized heterocyclic structures.
Applied in the preparation of indolyl-quinoline derivatives.
Used in heterocyclic chemistry research and molecular design.
6. Indirubin Derivatives Research
Used as a synthetic building block in research involving indirubin-related compounds.
Applied in the development of structurally modified indole-based molecules.
Supports research into biologically active heterocyclic compounds.
7. Fluorescence Spectroscopy Research
Used in studies of the photophysical properties of indole carboxylic acid compounds.
Applied in fluorescence spectroscopy and excited-state proton transfer research.
Used to investigate solvent-dependent fluorescence behavior.
8. Conductive Polymer Materials Research
Used as a monomer precursor for the preparation of poly(indole-5-carboxylic acid).
Applied in electrochemical polymerization research.
Used in the development and characterization of functional polymer films.
Supports research into electroactive polymer materials.
9. Fine Chemical Development
Used as a specialized intermediate in fine chemical synthesis.
Applied in the development of functional organic compounds.
Used in research involving novel molecular structures and chemical derivatives.
