55970-05-3

Basic information

• Product Name: 2,3-Dimethyl-1H-benzo[e]indole
• Synonyms: 2,3-dimethyl-1h-benzo[e]indole;1,2-Dimethyl-3H-benz[e]indole;2-Methyl-benz[e]indole;2,3-Dimethyl-benz(e)indole;1,2-DiMethyl-3H-benzo[e]indole
• CAS NO: 55970-05-3
• Molecular Formula: C₁₄H₁₃N
• Molecular Weight: 197.28
• Product Categories: Indole;Heterocycle-Indole series
• Mol File: 55970-05-3.mol
• Article Data: 4

Chemical Properties

• Melting Point: 118-121 °C
• Boiling Point: 341.8 °C at 760 mmHg
• Flash Point: 145.4 °C
• Appearance: /
• Density: 1.158
• PKA: 17.87±0.30(Predicted)
• CAS DataBase Reference: 2,3-Dimethyl-1H-benzo[e]indole(CAS DataBase Reference)
• NIST Chemistry Reference: 2,3-Dimethyl-1H-benzo[e]indole(55970-05-3)
• EPA Substance Registry System: 2,3-Dimethyl-1H-benzo[e]indole(55970-05-3)

Safety Data

• Hazardous Substances Data: 55970-05-3(Hazardous Substances Data)

Usage

General Description

2,3-Dimethyl-1H-benzo[e]indole, also known by its IUPAC name 1H-benzo[e]indole, 2,3-dimethyl-, is a chemical compound with the molecular formula C14H13N. It is a polycyclic aromatic hydrocarbon and a derivative of indole, commonly used in the production of pharmaceuticals, dyes, and as a building block for other organic compounds. It is a solid at room temperature, with a melting point of around 96-98°C, and it has a molecular weight of 195.26 g/mol. The compound is also known for its potential biological activity, with research indicating possible anti-cancer properties and other pharmacological effects. However, it is important to handle and use this chemical with caution due to its potential hazards to human health and the environment.

Synthetic route

2-naphthylhydrazine hydrochloride (2243-58-5) + butanone (78-93-3) → 2,3-dimethylbenz<4,5>indole (55970-05-3)

Conditions	Yield
With 4-methylbenzenesulfonic acid-based ionic liquid supported on silica gel In ethanol at 20℃; for 5h; Fischer Indole Synthesis;	86%
With acetic acid at 100℃; for 3h; Fischer Indole Synthesis; Inert atmosphere;

naphthalen-2-ylamine (91-59-8) + 2.3-butanediol (513-85-9) → 2,3-dimethylbenz<4,5>indole (55970-05-3)

Conditions	Yield
With bis[dichloro(pentamethylcyclopentadienyl)iridium(III)]; methanesulfonic acid at 170℃; for 48h; Inert atmosphere;	76%

2-naphthylhydrazine hydrochloride (2243-58-5) → 2,3-dimethylbenz<4,5>indole (55970-05-3)

Conditions	Yield
With ethanol; sodium acetate; butan-1-ol und Erwaermen der Reaktionsloesung mit konz.Schwefelsaeure;

naphthalen-2-ylamine (91-59-8) + β-bromo-levulinic acid → 2,3-dimethylbenz<4,5>indole (55970-05-3)

Conditions	Yield
Man kocht das Reaktionsprodukt mit sehr verduennter Salzsaeure aus und destilliert den Rueckstand unter vermindertem Druck;

<2-methyl-4.5-benzo-indolyl-(3)>-acetic acid → 2,3-dimethylbenz<4,5>indole (55970-05-3)

Conditions	Yield
at 210℃;

methylethyl ketone-β-naphthylhydrazone → 2,3-dimethylbenz<4,5>indole (55970-05-3)

Conditions	Yield
With zinc(II) chloride at 180℃;

2-naphthylhydrazine hydrochloride (2243-58-5) + 2-Pentanone (107-87-9) → 2,3-dimethylbenz<4,5>indole (55970-05-3)

Conditions	Yield
Stage #1: 2-naphthylhydrazine hydrochloride With acetic acid for 0.5h; Stage #2: 2-Pentanone Reflux;

2,3-dimethylbenz<4,5>indole (55970-05-3) + Allyl acetate (591-87-7) → 3-allyl-1,2-dimethyl-3H-benzo[e]indole

Conditions	Yield
With palladium(II) trifluoroacetate; trifuran-2-yl-phosphane In water for 2h; Reflux; Inert atmosphere; Green chemistry;	98%

2,3-dimethylbenz<4,5>indole (55970-05-3) + Allyl acetate (591-87-7) → 3-allyl-1,2-dimethyl-3H-benzo[e]indole + 1-allyl-1,2-dimethyl-1H-benzo[e]indole

Conditions	Yield
With platinum(II) 2,4-pentanedionate; tri(4-chlorophenyl)phosphine In water for 2h; Inert atmosphere; Reflux; regioselective reaction;	A 96% B 3%

styrene (100-42-5) + 2,3-dimethylbenz<4,5>indole (55970-05-3) + 5-(cyano)dibenzothiophenium triflate → C23H20N2

Conditions	Yield
Stage #1: 2,3-dimethylbenz<4,5>indole; 5-(cyano)dibenzothiophenium triflate In dichloromethane at 20℃; for 0.166667h; Inert atmosphere; Stage #2: styrene In dichloromethane at 20℃; for 11h; Inert atmosphere;	89%

2,3-dimethylbenz<4,5>indole (55970-05-3) + 5-(cyano)dibenzothiophenium triflate → C15H12N2

Conditions	Yield
In acetonitrile at 20℃; Inert atmosphere;	86%

2,3-dimethylbenz<4,5>indole (55970-05-3) → N-(1-formylnaphthalen-2-yl)acetamide (42900-57-2)

Conditions	Yield
With potassium phosphate; oxygen; Rose Bengal lactone In water; N,N-dimethyl-formamide for 46h; Inert atmosphere; Irradiation;	73%

2,3-dimethylbenz<4,5>indole (55970-05-3) + oxalic acid diethyl ester (95-92-1) → (1,2-Dimethyl-benzo[e]indol-3-yl)-oxo-acetic acid ethyl ester (114570-15-9)

Conditions	Yield
With ethylmagnesium bromide In ethanol for 2h;	72%

1-Phenylprop-1-yne (673-32-5) + 2,3-dimethylbenz<4,5>indole (55970-05-3) → 1-cinnamyl-1,2-dimethyl-1H-benzo[e]indole

Conditions	Yield
With tetrakis(triphenylphosphine) palladium(0); 4-Fluorobenzoic acid; tricyclohexylphosphine In toluene at 100℃; for 24h; Sealed tube; Inert atmosphere;	56%

2,3-dimethylbenz<4,5>indole (55970-05-3) + bis(4-tert-butylphenyl)iodonium hexafluorophosphate (61358-25-6) → 1,2-dimethyl-1-(4-tert-butylphenyl)-1H-benzo[e]indole

Conditions	Yield
Stage #1: 2,3-dimethylbenz<4,5>indole With potassium tert-butylate In toluene at 50℃; for 0.166667h; Inert atmosphere; Stage #2: bis(4-tert-butylphenyl)iodonium hexafluorophosphate In toluene at 50℃; for 18h; Inert atmosphere;	45%

2,3-dimethylbenz<4,5>indole (55970-05-3) + methyl 3-[[(methoxycarbonyl)imino]amino]but-2-enoate (63160-33-8) → (7aS*,10aR*)-methyl 8-((methoxycarbonyl)amino)-7a,9,10a-trimethyl-7,7a,8,10a-tetrahydrobenzo[e]pyrrolo[2,3-b]indole-10-carboxylate

Conditions	Yield
With zinc(II) chloride In dichloromethane at 25℃; diastereoselective reaction;	38%

2,3-dimethylbenz<4,5>indole (55970-05-3) + acetic anhydride (108-24-7) → 3,5-diacetyl-1,2-dimethyl-3H-benzo[e]indole (55993-18-5)

Conditions	Yield
unter Zusatz von wenig Phosphorsaeure oder Sulfanilsaeure;

2,3-dimethylbenz<4,5>indole (55970-05-3) → 3-acetyl-1,2-dimethyl-3H-benzo[e]indole (55970-09-7)

Conditions	Yield
With ethyl bromide; diethyl ether; magnesium und Erwaermen der Reaktionsloesung mit Acetylchlorid;

hydrogenchloride (7647-01-0) + 2,3-dimethylbenz<4,5>indole (55970-05-3) + ethanol (64-17-5) + zinc dust → 2.3-dimethyl-2.3-dihydro-4.5-benzo-indole

2,3-dimethylbenz<4,5>indole (55970-05-3) + methyl iodide (74-88-4) → hydriodide of 2.3.3-trimethyl-4.5-benzo-indolenine

Conditions	Yield
at 100℃;

2,3-dimethylbenz<4,5>indole (55970-05-3) → 1,2-Dimethyl-5,5-diphenyl-5H-benzo[e]pyrrolo[3,2,1-hi]indol-4-one (114570-23-9)

Conditions	Yield
Multi-step reaction with 3 steps 1: 72 percent / ethylmagnesium bromide / ethanol / 2 h 2: 68 percent / diethyl ether 3: 92 percent / H2SO4 / acetic acid / Heating View Scheme

2,3-dimethylbenz<4,5>indole (55970-05-3) → 1-(1,2-Dimethyl-benzo[e]indol-3-yl)-2-hydroxy-2,2-diphenyl-ethanone (114570-22-8)

Conditions	Yield
Multi-step reaction with 2 steps 1: 72 percent / ethylmagnesium bromide / ethanol / 2 h 2: 68 percent / diethyl ether View Scheme

2,3-dimethylbenz<4,5>indole (55970-05-3) → 3-acetyl-5-bromo-1,2-dimethyl-3H-benz[e]indole

Conditions	Yield
Multi-step reaction with 2 steps 1: magnesium; ethyl bromide; diethyl ether / und Erwaermen der Reaktionsloesung mit Acetylchlorid 2: acetic acid; bromine View Scheme

2,3-dimethylbenz<4,5>indole (55970-05-3) → 3,5-diacetyl-1,2-dimethyl-3H-benzo[e]indole (55993-18-5)

Conditions	Yield
Multi-step reaction with 2 steps 1: magnesium; ethyl bromide; diethyl ether / und Erwaermen der Reaktionsloesung mit Acetylchlorid 2: aluminium chloride; carbon disulfide View Scheme

2,3-dimethylbenz<4,5>indole (55970-05-3) → N-(1-acetyl-[2]naphthyl)-diacetamide

Conditions	Yield
Multi-step reaction with 2 steps 1: magnesium; ethyl bromide; diethyl ether / und Erwaermen der Reaktionsloesung mit Acetylchlorid 2: CrO3; acetic acid View Scheme

2,3-dimethylbenz<4,5>indole (55970-05-3) → 1,4-diacetyl-[2]naphthylamine

Conditions	Yield
Multi-step reaction with 4 steps 1: unter Zusatz von wenig Phosphorsaeure oder Sulfanilsaeure 2: aqueous acetic acid; CrO3 3: aqueous HCl 4: aqueous HCl View Scheme
Multi-step reaction with 5 steps 1: magnesium; ethyl bromide; diethyl ether / und Erwaermen der Reaktionsloesung mit Acetylchlorid 2: aluminium chloride; carbon disulfide 3: aqueous acetic acid; CrO3 4: aqueous HCl 5: aqueous HCl View Scheme

2,3-dimethylbenz<4,5>indole (55970-05-3) → N-(1,4-diacetyl-[2]naphthyl)-acetamide (861055-13-2)

Conditions	Yield
Multi-step reaction with 3 steps 1: unter Zusatz von wenig Phosphorsaeure oder Sulfanilsaeure 2: aqueous acetic acid; CrO3 3: aqueous HCl View Scheme
Multi-step reaction with 4 steps 1: magnesium; ethyl bromide; diethyl ether / und Erwaermen der Reaktionsloesung mit Acetylchlorid 2: aluminium chloride; carbon disulfide 3: aqueous acetic acid; CrO3 4: aqueous HCl View Scheme

2,3-dimethylbenz<4,5>indole (55970-05-3) → N-(1,4-diacetyl-[2]naphthyl)-diacetamide (666840-45-5)

Conditions	Yield
Multi-step reaction with 2 steps 1: unter Zusatz von wenig Phosphorsaeure oder Sulfanilsaeure 2: aqueous acetic acid; CrO3 View Scheme
Multi-step reaction with 3 steps 1: magnesium; ethyl bromide; diethyl ether / und Erwaermen der Reaktionsloesung mit Acetylchlorid 2: aluminium chloride; carbon disulfide 3: aqueous acetic acid; CrO3 View Scheme

2,3-dimethylbenz<4,5>indole (55970-05-3) + 1-phenyl-4-penten-1-yne (4289-20-7) → 1,2-dimethyl-1-((2E,4E)-5-phenylpenta-2,4-dien-1-yl)-1H-benzo[e]indole + 1,2-dimethyl-1-(5-phenylpenta-2,4-dien-1-yl)-1H-benzo[e]indole

Conditions	Yield
With tetrakis(triphenylphosphine) palladium(0); mesitylenecarboxylic acid; tricyclohexylphosphine In toluene at 100℃; for 24h; Sealed tube; Inert atmosphere; Overall yield = 55 %; Overall yield = 37.1 mg; chemoselective reaction;	A n/a B n/a
With tetrakis(triphenylphosphine) palladium(0); mesitylenecarboxylic acid; tricyclohexylphosphine In toluene at 100℃; for 24h; Sealed tube; Inert atmosphere; Overall yield = 55 percent; Overall yield = 37.1 mg;	A n/a B n/a

Upstream product

• 2243-58-5 2-naphthylhydrazine hydrochloride 
• 91-59-8 naphthalen-2-ylamine 
• 513-85-9 2.3-butanediol 
• 78-93-3 butanone 
• 107-87-9 2-Pentanone 

Downstream Products

• 114570-23-9 1,2-Dimethyl-5,5-diphenyl-5H-benzo[e]pyrrolo[3,2,1-hi]indol-4-one 
• 114570-22-8 1-(1,2-Dimethyl-benzo[e]indol-3-yl)-2-hydroxy-2,2-diphenyl-ethanone 

Relevant articles and documents

Palladium-Catalyzed Amination/Dearomatization Reaction of Indoles and Benzofurans

This report describes a palladium-catalyzed dearomatization and amination tandem reaction of 2,3-disubstituted indoles and benzofurans via the Catellani strategy. This reaction provides a new method for the construction of amino-substituted indoline-fused cyclic and benzofuran spiro compounds in good yields. The reaction has broad functional group compatibility and substrate scope.

Palladium-Catalyzed Dearomative Allylic Alkylation of Indoles with Alkynes to Synthesize Indolenines with C3-Quarternary Centers

A palladium-catalyzed dearomative allylic alkylation of indoles with alkynes to construct indolenines with C3-quarternary centers was reported. The in situ formed arylallene intermediate omitted the need to install leaving groups on the allylic compounds and employ extra oxidants to oxidize the allylic C-H bonds. The reaction exhibited good functional group tolerance and high atom economy. Moreover, the reaction was further expanded to synthesize pyrroloindolines and furanoindolines.