2024-05-06by admin0

2-methylindole structural formula

Structural formula

Physical competition number 028R
Molecular formula C9H9N
Molecular weight 131.17






Numbering system

CAS number:95-20-5

MDL number:MFCD00005616

EINECS number:202-398-3

RTECS number:NM0345000

BRN number:109781

PubChem number:24896980

Physical property data

1. Properties: White needle-like or flaky crystalline powder.

2. Density (g/mL, 20℃): 1.07

3. Relative vapor density (g/mL, air=1): Undetermined

4. Melting point (ºC): 61

5. Boiling point (ºC, normal pressure): Undetermined

6. Boiling point (ºC, 0.67KPa): 272

7. Refractive index: Undetermined

8. Flash point (ºC): 141

9. Specific rotation (º): Undetermined

10. Autoignition point or ignition temperature (ºC): Undetermined

11. Vapor pressure (mmHg,ºC): Undetermined

12. Saturated vapor pressure (kPa,ºC ): Undetermined

13. Heat of combustion (KJ/mol): Undetermined

14. Critical temperature (ºC): Undetermined

15. Critical Pressure (KPa): Undetermined

16. Log value of oil-water (octanol/water) distribution coefficient: Undetermined

17. Explosion upper limit (%, V/V): Undetermined

18. Lower explosion limit (%, V/V): Undetermined

19. Solubility: Easily soluble in ethanol, ether, soluble in acetone, benzene, chloroform and Sulfuric acid is slightly soluble in hot water and insoluble in cold water.

Toxicological data

1. Acute toxicity: mouse intraperitoneal LD50: >262mg/kg;

Ecological data

Slightly harmful to water.

Molecular structure data

1. Molar refractive index: 43.35

2. Molar volume (cm3/mol): 106.2

3. Isotonic specific volume (90.2K ): 308.3

4. Surface tension (dyne/cm): 46.4

5. Polarizability (10-24cm3): 17.18

Compute chemical data

1. Reference value for hydrophobic parameter calculation (XlogP): None

2. Number of hydrogen bond donors: 1

3. Number of hydrogen bond acceptors: 0

4. Number of rotatable chemical bonds: 0

5. Number of tautomers: none

6. Topological molecule polar surface area 15.8

7. Number of heavy atoms: 10

8. Surface charge: 0

9. Complexity: 122

10. Number of isotope atoms: 0

11. Determine the number of atomic stereocenters: 0

12. The number of uncertain stereocenters of atoms: 0

13. The number of determined stereocenters of chemical bonds: 0

14. The number of uncertain stereocenters of chemical bonds: 0

15. Number of covalent bond units: 1

Properties and stability

Can evaporate with water vapor. Its ethanol, ether, benzene and chloroform solutions emit purple to blue-green fluorescence under daylight. Decomposes when heated with concentrated hydrochloric acid. Has a special smell. Avoid contact with oxides and acids.

Storage method

Stored sealed in a cool, dry place. Make sure the workspace has good ventilation. Keep sealed. Keep away from fire sources and store away from oxidants and acidic substances.

Synthesis method

It is prepared from N-acetyl o-toluidine through the following steps. Add N-acetyl o-toluidine to the mixture of anhydrous ether and sodium amide, heat to 240-260°C under the protection of nitrogen flow, and keep it for 10 minutes. The reaction will produce a large amount of gas. When the gas stops escaping, the reaction is completed and cooled. Add ethanol and warm water, and heat to decompose the generated sodium derivative of 2-methylindole and excess sodium amide. After cooling, extract with diethyl ether. The extract is concentrated and then distilled, and the 119-126°C (0.4-0.53kPa) fraction is collected to obtain 2-methylindole with a yield of 80%-83%. This product can be purified by recrystallization from methanol.


It is used in organic synthesis and can be used as a fixative in the fragrance industry.


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