36729-21-2

Basic information

• Product Name: 2,3-dimethyl-1H-benzo[g]indole
• Synonyms: 1H-Benz(g)indole, 2,3-dimethyl-; 1H-benz[g]indole, 2,3-dimethyl-; 2,3-Dimethyl-1H-benz(g)indole
• CAS NO: 36729-21-2
• Molecular Formula: C₁₄H₁₃N
• Molecular Weight: 195.2597
• Mol File: 36729-21-2.mol
• Article Data: 10

Chemical Properties

• Boiling Point: 391.1°C at 760 mmHg
• Flash Point: 175.2°C
• Density: 1.158g/cm³
• Vapor Pressure: 5.69E-06mmHg at 25°C
• Refractive Index: 1.712
• CAS DataBase Reference: 2,3-dimethyl-1H-benzo[g]indole(CAS DataBase Reference)
• NIST Chemistry Reference: 2,3-dimethyl-1H-benzo[g]indole(36729-21-2)
• EPA Substance Registry System: 2,3-dimethyl-1H-benzo[g]indole(36729-21-2)

Safety Data

• Hazardous Substances Data: 36729-21-2(Hazardous Substances Data)

Upstream product

• 134-32-7 1-amino-naphthalene 
• 513-85-9 2.3-butanediol 
• 114570-16-0 (2,3-Dimethyl-benzo[g]indol-1-yl)-oxo-acetic acid ethyl ester 
• 121198-11-6 (E)-N-(2-butenyl)-1-naphthylamine 
• 2243-56-3 1-naphthylhydrazine hydrochloride 
• 78-93-3 butanone 
• 2028-63-9 but-3-yn-2-ol 

Relevant articles and documents

Acceptorless dehydrogenative condensation: synthesis of indoles and quinolines from diols and anilines

The use of diols and anilines as reagents for the preparation of indoles represents a challenge in organic synthesis. By means of acceptorless dehydrogenative condensation, heterocycles, such as indoles, can be obtained. Herein we present an experimental and theoretical study for this purpose employing heterogeneous catalysts Pt/Al2O3and ZnO in combination with an acid catalyst (p-TSA) and NMP as solvent. Under our optimized conditions, the diol excess has been reduced down to 2 equivalents. This represents a major advance, and allows the use of other diols. 2,3-Butanediol or 1,2-cyclohexanediol has been employed affording 2,3-dimethyl indoles and tetrahydrocarbazoles. In addition, 1,3-propanediol has been employed to prepare quinolines or natural and synthetic julolidines.

Catalytic Synthesis of Substituted Indoles and Quinolines from the Dehydrative C-H Coupling of Arylamines with 1,2- and 1,3-Diols

The cationic ruthenium-hydride complex catalyzes the dehydrative C-H coupling reaction of arylamines with 1,2-diols to form the indole products. The analogous coupling of arylamines with 1,3-diols afforded the substituted quinolines. The catalytic method directly forms these coupling products in a highly regioselective manner without generating any toxic byproducts.

Iridium- and ruthenium-catalysed synthesis of 2,3-disubstituted indoles from anilines and vicinal diols

A straightforward and atom-economical method is described for the synthesis of 2,3-disubstituted indoles. Anilines and 1,2-diols are condensed under neat conditions with catalytic amounts of either [Cp*IrCl2] 2/MsOH or RuCl3·xH2O/phosphine (phosphine = PPh3 or xantphos). The reaction does not require any stoichiometric additives and only produces water and dihydrogen as byproducts. Anilines containing methyl, methoxy, chloro and fluoro substituents can participate in the cyclocondensation. Meta-substituted anilines give good regioselectivity for 6-substituted indoles, while unsymmetrical diols afford excellent regioselectivity for the indole isomer with an aryl or large alkyl group in the 2-position. The mechanism for the cyclocondensation presumably involves initial formation of the α-hydroxyketone from the diol. The ketone subsequently reacts with aniline to generate the α-hydroxyimine which rearranges to the corresponding α-aminoketone. Acid- or metal-catalysed electrophilic ring-closure with the release of water then furnishes the indole product.