Indole

Base Information

• Chemical Name: Indole
• CAS No.: 120-72-9
• Molecular Formula: C8H7N
• Molecular Weight: 117.15
• Hs Code.: 2933 99 20
• European Community (EC) Number: 204-420-7
• NSC Number: 1964
• UNII: 8724FJW4M5
• DSSTox Substance ID: DTXSID0020737
• Nikkaji Number: J2.920C
• Wikipedia: Indole
• Wikidata: Q319541
• NCI Thesaurus Code: C68534
• Metabolomics Workbench ID: 37398
• ChEMBL ID: CHEMBL15844
• Mol file: 120-72-9.mol

Synonyms:indole;indole hydrochloride;indole, 14C-labeled

Chemical Property of Indole

Chemical Property:

• Appearance/Colour: white crystals with an unpleasant odour
• Vapor Pressure: 0.0298mmHg at 25°C
• Melting Point: 51-54 °C(lit.)
• Refractive Index: 1.68
• Boiling Point: 253 °C at 760 mmHg
• PKA: 3.17 (quoted, Sangster, 1989)
• Flash Point: 107.839 °C
• PSA: 15.79000
• Density: 1.22 g/cm³
• LogP: 2.16790
• Storage Temp.: 2-8°C
• Sensitive.: Light Sensitive
• Solubility.: methanol: 0.1 g/mL, clear
• Water Solubility.: 2.80 g/L (25 ºC)
• XLogP3: 2.1
• Hydrogen Bond Donor Count: 1
• Hydrogen Bond Acceptor Count: 0
• Rotatable Bond Count: 0
• Exact Mass: 117.057849228
• Heavy Atom Count: 9
• Complexity: 101

Purity/Quality:

99% ^*data from raw suppliers

Indole ^*data from reagent suppliers

Safty Information:

• Pictogram(s): Xn,N,T
• Hazard Codes: Xn,N,T
• Statements: 21/22-37/38-41-50/53-36-39/23/24/25-23/24/25-52/53
• Safety Statements: 26-36/37/39-60-61-45-36/37

MSDS Files:

SDS file from LookChem

Total 1 MSDS from other Authors

Useful:

• Chemical Classes: Nitrogen Compounds -> Indoles
• Canonical SMILES: C1=CC=C2C(=C1)C=CN2
• description: Indole, also called Benzopyrrole, an aromatic heterocyclic organic compound occurring in some flower oils, such as jasmine and orange blossom, in coal tar, and in fecal matter. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing pyrrole ring. It can be produced by bacteria as a degradation product of the amino acid tryptophan. It occurs naturally in human feces and has an intense fecal smell. This off flavour occurs in beer due to contaminant coliform bacteria during the primary fermentation stage of beer brewing. At very low concentrations, however, it has a flowery smell, and is a constituent of many flower scents (such as orange blossoms) and perfumes. Natural jasmine oil, used in the perfume industry, contains around 2.5% of indole. Indole also occurs in coal tar. The participation of the nitrogen lone electron pair in the aromatic ring means that indole is not a base, and it does not behave like a simple amine. Indoles are important precursors for other substances made within the human body and are, therefore, researched and used in lifestyle and medical applications. The compound was officially discovered in 1866 by a scientist working with the properties of zinc dust who reduced oxindole from the zinc dust into an indole. After the discovery, indoles became important constituents of the textile industry, and as more research was conducted, the larger role that indoles played within the human body system was realized. The indolic nucleus in substances like tryptophan and auxin has led to a better understanding of their mechanism within the body.
• Uses: (1) According to the GB 27 60-96 , indole can be used as flavouring agent and mainly used for preparing the essence of cheese, citrus, coffee, nuts, grape, strawberry, raspberry, chocolate, assorted fruit, jasmine and lily etc. (2) It can be used as the reagent for the determination of nitrite, can also used in the manufacture of perfume and medicine. (3) It can be used as the raw material of perfume, pharmaceuticals and plant growth hormone. (4) Indole is the intermediate for the indole acetic acid and indole butyric acid.The indole acetic acid and indole butyric are plant growth regulator. (5) It can be widely used in the manufacture of the essences of jasmine, lilac, orange blossom, gardenia, honeysuckle, lotus, narcissus, ylang, orchid and prynne etc. It is usually combined with the methyl indole to imitate the artificial civet. The extremely few of the indole can be used in chocolate, raspberry, strawberry, bitter orange, coffee, nuts, cheese, grapes and fruit and other fruity essential oil. (6) Indole is mainly used as spices, dyes, amino acids and the raw materials of pesticide. Indole itself is a spice commonly used in producing the essences of jasmine, lilac, lotus flowers, orchids and other flower flavor. The usage is generally in a few thousandths. (7) It can be used for verifying the gold, potassium and nitrite and manufacturing jasmine-type fragrance. It can also be used in pharmaceutical industry. Indole occurs in coal tar. It is used, underhigh dilution, in perfumery, and as an intermediatein organic synthesis. Can be used in perfumes and in the synthesis of tryptophan. In highly dil solutions the odor is pleasant, hence indole has been used in perfumery. Indole is a flavoring agent that is a white, flaky crystalline product. it has an unpleasant odor when concentrated and a flowery odor when diluted. it is soluble in most fixed oils and propylene glycol and insoluble in glycerin and mineral oil. it is obtained from decomposi- tion of a protein.
• Description: Indole has an almost floral odor when highly purified. Otherwise, it exhibits the characteristic odor of feces. It is not very stable on exposure to light (turns red). Indole may be obtained from the 220 - 260°C boiling fraction of coal tar or by heating sodium phenylglycine-o-carboxylate with NaOH, saturating the aqueous solution of the melt with C 02, and finally reducing with sodium amalgam; can be prepared also by the reduction of indoxyl, indoxyl carboxylic acid, or indigo.
• Physical properties: Colorless to yellow scales with an unpleasant odor. Turns red on exposure to light and air. Odor threshold of 0.14 ppm was reported by Buttery et al. (1988).

Technology Process of Indole

There total 688 articles about Indole which guide to synthetic route it. The literature collected by LookChem mainly comes from the sharing of users and the free literature resources found by Internet computing technology. We keep the original model of the professional version of literature to make it easier and faster for users to retrieve and use. At the same time, we analyze and calculate the most feasible synthesis route with the highest yield for your reference as below:

synthetic route:

Reference yield: 72.0%

1-indoline (496-15-1) + phenylethane 1,2-diol (93-56-1) → styrene (100-42-5,25038-60-2,25247-68-1,28213-80-1,28325-75-9,79637-11-9,9003-53-6) + indole (120-72-9)

Guidance literature:

With methyltrioxorhenium(VII); In toluene; at 190 ℃; for 2.5h; Reagent/catalyst; Solvent; regioselective reaction;

DOI:10.1016/j.poly.2018.11.061

Reference yield: 71.4%

aniline (62-53-3) + glycerol (56-81-5,25618-55-7,64333-26-2,8013-25-0) → quinoline (91-22-5) + indole (120-72-9) + 2-methylquinoline (91-63-4) + C6H4NCH2CHCCH2 (491-35-0) + N-ethyl-N-phenylamine (103-69-5)

Guidance literature:

With mesoporous nickel beta zeolite; In water; at 470 ℃; for 2h; Reagent/catalyst; Inert atmosphere; Green chemistry;

DOI:10.1039/c6ra26736j

Reference yield: 64.8%

β-phenethylsulfonyl azide (54664-50-5) → styrene (100-42-5,25038-60-2,25247-68-1,28213-80-1,28325-75-9,79637-11-9,9003-53-6) + indole (120-72-9) + 1-indoline (496-15-1) + 2,3-cyclopentenopyridine (533-37-9)

Guidance literature:

at 650 ℃; for 6.94444E-05h; Product distribution; other temperature, time;

DOI:10.1021/ja00396a039

upstream raw materials:

3-Methylindole

tetrachloromethane

1-indoline

chloranil

Downstream raw materials:

N-morpholinyl-3-indolylmethylamine

indole-3-carbinol

3-(2-Pyrrolidinyl)-indol

1-trityl-indole

Refernces

• 1、 Chen, Jinchun,Zhang, Zhikai,Liu, Sujing,Yang, Cuiyun,Xia, Chuanhai. "One-pot tandem synthesis of 2,3-unsubstituted indoles, an improved Leimgruber-Batchoindole synthesis". . p. 4672 - 4675. Retrieved 2014.
• 2、 Phillips, Robert S.,Ghaffari, Rashin,Dinh, Peter,Lima, Santiago,Bartlett, Douglas. "Properties of tryptophan indole-lyase from a piezophilic bacterium, Photobacterium profundum SS9". . p. 35 - 41. Retrieved 2011.
• 3、 Clarke, Aimee K.,Lynam, Jason M.,Taylor, Richard J. K.,Unsworth, William P.. " back-to-Front Indole Synthesis Using Silver(I) Catalysis: Unexpected C-3 Pyrrole Activation Mode Supported by DFT". . p. 6844 - 6850. Retrieved 2018.
• 4、 Ge, Jingjie,Yin, Peiqun,Chen, Ye,Cheng, Hongfei,Liu, Jiawei,Chen, Bo,Tan, Chaoliang,Yin, Peng-Fei,Zheng, Hong-Xing,Li, Qiang-Qiang,Chen, Shuangming,Xu, Wenjie,Wang, Xiaoqian,Wu, Geng,Sun, Rongbo,Shan, Xiang-Huan,Hong, Xun,Zhang, Hua. "Ultrathin Amorphous/Crystalline Heterophase Rh and Rh Alloy Nanosheets as Tandem Catalysts for Direct Indole Synthesis". . . Retrieved 2021.
• 5、 Li, Beibei,Ju, Zhanfeng,Zhou, Mi,Su, Kongzhao,Yuan, Daqiang. "A Reusable MOF-Supported Single-Site Zinc(II) Catalyst for Efficient Intramolecular Hydroamination of o-Alkynylanilines". . p. 7687 - 7691. Retrieved 2019.
• 6、 Trofimov,Mikhaleva,Schmidt,Protsuk,Ivanov,Ryapolov. "A catalyst for the selective dehydrogenation of 4,5,6,7-tetrahydroindole into indole". . p. 95 - 97. Retrieved 2011.
• 7、 Keirs, David,Overton, Karl. "Conversion of Amines into Imines by Swern Oxidation". . p. 1660 - 1661. Retrieved 1987.
• 8、 Preobrazhenskaya, Maria N.,Korolev, Alexander M.,Rozhkov, Ilya I.,Yudina, Larisa N.,Lazhko, Eduard I.,Aiello, Enrico,Almerico, Anna Maria,Mingoia, Francesco. "From ascorbigens to indolocarbazoles". . p. 265 - 274. Retrieved 1999.
• 9、 Panunzio et al.. "-". . p. 415. Retrieved 1972.
• 10、 Martinez, Silvio J.,Dalton, Lesley,Joule, John A.. "CYCLIC ALLYLAMINE/ENAMINE SYSTEMS-6 SOME REACTIONS OF 4-(INDOL-2-YLCARBONYL)-, 4-(INDOL-3-YLCARBONYL)- AND 4-(INDOL-3-YLMETHYL)-1,2,5,6-TETRAHYDRO-1-METHYLPYRIDINES". . p. 3339 - 3344. Retrieved 1984.