174775-48-5

Basic information

• Product Name: ETHYL 5-AMINOBENZOFURAN-2-CARBOXYLATE
• Synonyms: ETHYL 5-AMINOBENZOFURAN-2-CARBOXYLATE;2-Benzofurancarboxylicacid,5-amino-,ethylester(9CI);Ethyl 5-aminobenzo[b]furan-2-carboxylate;Ethyl 5-amino-1-benzofuran-2-carboxylate (en);5-Amino-2-(ethoxycarbonyl)-1-benzofuran;5-Amino-2-(ethoxycarbonyl)-1-benzofuran, Ethyl 5-amino-1-benzofuran-2-carboxylate;2-Benzofurancarboxylicacid, 5-aMino-, ethyl ester;Vilazodone INT 5
• CAS NO: 174775-48-5
• Molecular Formula: C₁₁H₁₁NO₃
• Molecular Weight: 205.21
• EINECS: 1806241-263-5
• Product Categories: AMINOACID;Esters;Furans, Benzofurans & Dihydrobenzofurans
• Mol File: 174775-48-5.mol
• Article Data: 15

Chemical Properties

• Melting Point: 54-56°C
• Boiling Point: 348.067 °C at 760 mmHg
• Flash Point: 164.306 °C
• Appearance: Beige/Powder
• Density: 1.259 g/cm³
• Vapor Pressure: 0mmHg at 25°C
• Refractive Index: 1.617
• Storage Temp.: under inert gas (nitrogen or Argon) at 2–8 °C
• PKA: 3.32±0.10(Predicted)
• CAS DataBase Reference: ETHYL 5-AMINOBENZOFURAN-2-CARBOXYLATE(CAS DataBase Reference)
• NIST Chemistry Reference: ETHYL 5-AMINOBENZOFURAN-2-CARBOXYLATE(174775-48-5)
• EPA Substance Registry System: ETHYL 5-AMINOBENZOFURAN-2-CARBOXYLATE(174775-48-5)

Safety Data

• Hazard Codes: Xi
• HazardClass: IRRITANT
• Hazardous Substances Data: 174775-48-5(Hazardous Substances Data)

Usage

Chemical Properties

Brown Solid

Uses

Different sources of media describe the Uses of 174775-48-5 differently. You can refer to the following data:
1. Ethyl 5-aminobenzofuran-2-carboxylate is used as an synthetic intermediate in the preparation of indolebutylpiperazines, a class of dual 5-HT1A receptor agonists and serotonin reuptake inhibitors. Ethyl 5-amino-1-benzofuran-2-carboxylate was also used as a potential radiolabelled analog for melanoma imaging and targeted radiotherapy.
2. Ethyl 5-amino-1-benzofuran-2-carboxylate is used as an synthetic intermediate in the preparation of indolebutylpiperazines, a class of dual 5-HT1A receptor agonists and serotonin reuptake inhibitors. Ethyl 5-amino-1-benzofuran-2-carboxylate was also used as a potential radiolabelled analog for melanoma imaging and targeted radiotherapy.

InChI:InChI=1/C11H11NO3/c1-2-14-11(13)10-6-7-5-8(12)3-4-9(7)15-10/h3-6H,2,12H2,1H3

Synthetic route

ethyl 5-nitrobenzo[d]furan-2-carboxylate (69604-00-8) → ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5)

Conditions	Yield
With palladium 10% on activated carbon; hydrogen In ethyl acetate at 33 - 38℃; under 3000.3 - 3750.38 Torr;	100%
With palladium 10% on activated carbon; hydrogen In ethyl acetate at 33 - 38℃; under 3000.3 - 3750.38 Torr;	100%
With hydrogen In ethyl acetate; N,N-dimethyl-formamide under 760.051 Torr; for 4h; Heating; Flow reactor; Green chemistry;	99%

salicylaldehyde (90-02-8) → ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5)

Conditions	Yield
With hydrogen In ethanol at 20℃; for 6h;	91%
Multi-step reaction with 3 steps 1: nitric acid / acetic acid 2: sodium carbonate / 1-methyl-pyrrolidin-2-one 3: hydrogen View Scheme

5-Nitrosalicylaldehyde (97-51-8) → ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5)

Conditions	Yield
Multi-step reaction with 2 steps 1: potassium carbonate / N,N-dimethyl-formamide / 15 h / 85 - 90 °C / Inert atmosphere 2: hydrogen; palladium 10% on activated carbon / ethyl acetate / 33 - 38 °C / 3000.3 - 3750.38 Torr View Scheme
Multi-step reaction with 2 steps 1: sodium carbonate / 1-methyl-pyrrolidin-2-one 2: hydrogen View Scheme
Multi-step reaction with 2 steps 1: potassium carbonate / N,N-dimethyl-formamide / 15 h / 30 - 90 °C / Inert atmosphere 2: palladium 10% on activated carbon; hydrogen / ethyl acetate / 33 - 38 °C / 3000.3 - 3750.38 Torr View Scheme

6-nitrocoumarin (2725-81-7) → ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: bromine / chloroform / 0 - 20 °C 2.1: 1 h / Reflux 2.2: 8 h / Reflux 3.1: hydrogen; 5%-palladium/activated carbon / ethanol / 3 h / 10 - 30 °C / 2250.23 - 3750.38 Torr View Scheme
Multi-step reaction with 4 steps 1: bromine / chloroform / 0 - 20 °C 2: 1 h / Reflux 3: triethylamine / ethanol / 8 h / Reflux 4: hydrogen; 5%-palladium/activated carbon / ethanol / 3 h / 10 - 30 °C / 2250.23 - 3750.38 Torr View Scheme
Multi-step reaction with 4 steps 1: sodium hydroxide / ethanol; water / 4 h / Reflux 2: copper dichloride; caesium carbonate / N,N-dimethyl-formamide / 5 h / 100 °C 3: sulfuric acid / 2 h / Reflux 4: 5%-palladium/activated carbon; hydrogen / ethanol / 3 h / 30 °C / 3000.3 - 3750.38 Torr View Scheme

3,4-dibromo-6-nitrochroman-2-one → ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5)

Conditions	Yield
Multi-step reaction with 2 steps 1.1: 1 h / Reflux 1.2: 8 h / Reflux 2.1: hydrogen; 5%-palladium/activated carbon / ethanol / 3 h / 10 - 30 °C / 2250.23 - 3750.38 Torr View Scheme
Multi-step reaction with 3 steps 1: 1 h / Reflux 2: triethylamine / ethanol / 8 h / Reflux 3: hydrogen; 5%-palladium/activated carbon / ethanol / 3 h / 10 - 30 °C / 2250.23 - 3750.38 Torr View Scheme

3-(2-hydroxy-5-nitrophenyl)acrylic acid (50396-49-1) → ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5)

Conditions	Yield
Multi-step reaction with 3 steps 1: copper dichloride; caesium carbonate / N,N-dimethyl-formamide / 5 h / 100 °C 2: sulfuric acid / 2 h / Reflux 3: 5%-palladium/activated carbon; hydrogen / ethanol / 3 h / 30 °C / 3000.3 - 3750.38 Torr View Scheme

5-nitrobenzofuran-2-carboxylic acid (10242-12-3) → ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5)

Conditions	Yield
Multi-step reaction with 2 steps 1: sulfuric acid / 2 h / Reflux 2: 5%-palladium/activated carbon; hydrogen / ethanol / 3 h / 30 °C / 3000.3 - 3750.38 Torr View Scheme

C17H27NO3Si2 → ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5)

Conditions	Yield
With hydrogenchloride In chloroform; water for 1h;	63.3 mg

(2S,3S)-1-(tert-butoxycarbonyl)-3-(2-methylphenyl)pyrrolidine-2-carboxylic acid + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → tert-butyl (2S,3S)-2-{[2-(ethoxycarbonyl)-1-benzofuran-5-yl]carbamoyl}-3-(2-methylphenyl)pyrrolidine-1-carboxylate

Conditions	Yield
Stage #1: (2S,3S)-1-(tert-butoxycarbonyl)-3-(2-methylphenyl)pyrrolidine-2-carboxylic acid With N-ethyl-N,N-diisopropylamine; N-[(dimethylamino)-3-oxo-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl-methylene]-N-methylmethanaminium hexafluorophosphate In N,N-dimethyl-formamide at 20℃; for 0.25h; Stage #2: ethyl 5-amino-1-benzofuran-2-carboxylate In N,N-dimethyl-formamide at 20 - 70℃; for 5h;	99%

ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → C11H9(2)H2NO3

Conditions	Yield
With C40H51ClIrN3; potassium carbonate; deuterium In dichloromethane at 50℃; under 760.051 Torr; for 12h; Sealed tube; Inert atmosphere; regioselective reaction;	96%

4-[(tert-butoxycarbonyl)amino]-1-methyl-1H-pyrrole-2-carboxylic acid (77716-11-1) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → C22H25N3O6

Conditions	Yield
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In N,N-dimethyl-formamide	90%

4-hydroxy[1]benzopyran-2-one (1076-38-6) + 4-bromo-benzaldehyde (1122-91-4) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 13-(4-bromophenyl)-12-oxo-6,13-dihydro-12H-chromeno[4,3-b]furo[3,2-f]quinoline-2-carboxylate

Conditions	Yield
In N,N-dimethyl-formamide at 100℃; for 6h;	90%

formamide (77287-34-4, 77287-35-5, 60100-09-6) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → C10H8N2O3 (1418125-60-6)

Conditions	Yield
With sodium methylate at 20℃; for 6h;	86%

1,3-cyclopentadione (3859-41-4) + 2,6-dichlorobenzaldehyde (83-38-5) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 10-(2,6-dichlorophenyl)-9-oxo-7,8,9,10-tetrahydro-6H-cyclopenta[b]furo[3,2-f]quinoline-2-carboxylate

Conditions	Yield
In N,N-dimethyl-formamide at 100℃; for 8h;	86%

4-hydroxy[1]benzopyran-2-one (1076-38-6) + 4-chlorobenzaldehyde (104-88-1) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 13-(4-chlorophenyl)-12-oxo-6,13-dihydro-12H-chromeno[4,3-b]furo[3,2-f]quinoline-2-carboxylate

Conditions	Yield
In N,N-dimethyl-formamide at 100℃; for 6h;	85%

bis-(2-chloroethyl)amine hydrochloride (821-48-7) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → 5-(piperazin-1-yl)benzofuran-2-carboxylic acid ethyl ester

Conditions	Yield
With sodium carbonate In isopropyl alcohol at 50 - 60℃; for 4h;	85%
With sodium carbonate In ethanol at 50 - 60℃; for 4h;	83.1%

1,3-cyclopentadione (3859-41-4) + 3,4-dimethoxy-benzaldehyde (120-14-9) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 10-(3,4-dimethoxyphenyl)-9-oxo-7,8,9,10-tetrahydro-6H-cyclopenta[b]furo[3,2-f]quinoline-2-carboxylate

Conditions	Yield
In N,N-dimethyl-formamide at 100℃; for 10h;	84%

tetrafluoroboric acid + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → 2‐(ethoxycarbonyl)‐1‐benzofuran‐5‐diazonium tetrafluoroborate (1618107-87-1)

Conditions	Yield
Stage #1: tetrafluoroboric acid; ethyl 5-amino-1-benzofuran-2-carboxylate In ethanol; water at 20℃; for 0.0333333h; Stage #2: With tert.-butylnitrite In ethanol; water at 0 - 20℃; for 1.25h;	83%

2-((2RS,3RS)-3-ethyloxiran-2-yl)ethan-1-ol (67393-83-3, 67393-84-4, 67663-02-9, 91603-21-3, 91603-22-4, 118759-60-7, 118759-61-8) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → C17H23NO5

Conditions	Yield
With 3,4,5-trifluorophenylboronic acid In toluene at 60℃; for 24h; regioselective reaction;	83%

1,3-cyclopentadione (3859-41-4) + 2,4-dichlorobenzaldeyhde (874-42-0) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 10-(2,4-dichlorophenyl)-9-oxo-7,8,9,10-tetrahydro-6H-cyclopenta[b]furo[3,2-f]quinoline-2-carboxylate

Conditions	Yield
In N,N-dimethyl-formamide at 100℃; for 8h;	82%

bis-(2-chloroethyl)amine hydrochloride (821-48-7) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 5-(1-piperazinyl)benzofuran-2-carboxylate dihydrochloride

Conditions	Yield
Stage #1: bis-(2-chloroethyl)amine hydrochloride; ethyl 5-amino-1-benzofuran-2-carboxylate With tetrabutylammomium bromide; potassium carbonate In o-xylene at 135 - 140℃; for 32h; Stage #2: With hydrogenchloride In dichloromethane; water	81.3%
Stage #1: bis-(2-chloroethyl)amine hydrochloride; ethyl 5-amino-1-benzofuran-2-carboxylate With tetrabutylammomium bromide; potassium carbonate In o-xylene at 20 - 140℃; for 32h; Stage #2: With hydrogenchloride In dichloromethane; water	81.3%

bis-(2-chloroethyl)amine hydrochloride (821-48-7) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 5-(1-piperazinyl)benzofuran-2-carboxylate hydrobromide (1469427-45-9)

Conditions	Yield
Stage #1: bis-(2-chloroethyl)amine hydrochloride; ethyl 5-amino-1-benzofuran-2-carboxylate With tetrabutylammomium bromide; potassium carbonate In o-xylene at 135 - 140℃; for 32h; Stage #2: With hydrogen bromide In dichloromethane; water	81.3%

bis-(2-chloroethyl)amine hydrochloride (821-48-7) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 5-(1-piperazinyl)benzofuran-2-carboxylate hydrobromide

Conditions	Yield
Stage #1: bis-(2-chloroethyl)amine hydrochloride; ethyl 5-amino-1-benzofuran-2-carboxylate With tetrabutylammomium bromide; potassium carbonate In o-xylene at 20 - 140℃; for 32h; Stage #2: With hydrogen bromide In dichloromethane; water	81.3%

1,3-cyclopentadione (3859-41-4) + 4-chlorobenzaldehyde (104-88-1) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 10-(4-chlorophenyl)-9-oxo-7,8,9,10-tetrahydro-6H-cyclopenta[b]furo[3,2-f] quinoline-2-carboxylate

Conditions	Yield
In N,N-dimethyl-formamide at 100℃; for 8h;	79%

Phenyl-vinyl-glykolsaeure (1626-05-7) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → C21H17NO4

Conditions	Yield
With tris(dibenzylideneacetone)dipalladium(0) chloroform complex; 1,1'-bis-(diphenylphosphino)ferrocene In acetonitrile at 25℃; for 12h;	73%

methanesulfonyl chloride (124-63-0) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 5-(methylsulfonamido)benzofuran-2-carboxylate

Conditions	Yield
With pyridine at 0 - 20℃; for 3h;	72%

tetrahydroxydiboron (13675-18-8) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → 2-(ethoxycarbonyl)benzofuran-5-ylboronic acid (1618107-90-6)

Conditions	Yield
Stage #1: ethyl 5-amino-1-benzofuran-2-carboxylate With hydrogenchloride; sodium nitrite In water at 0℃; for 0.25h; Stage #2: tetrahydroxydiboron With sodium acetate In water at 20℃; for 0.333333h;	70.5%

acetic acid (64-19-7) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 5-acetamidobenzofuran-2-carboxylate

Conditions	Yield
With benzotriazol-1-ol; O-(1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate; N-ethyl-N,N-diisopropylamine In N,N-dimethyl-formamide at 20℃; for 15h;	66%

Langlois reagent (2926-29-6) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 5-isothiocyanatobenzofuran-2-carboxylate

Conditions	Yield
With copper(l) iodide; phosphonic acid diethyl ester In toluene at 110℃; for 16h; Schlenk technique; Green chemistry;	61%

triphenyl phosphite (101-02-0) + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 5-(diphenoxyphosphoryl)benzofuran-2-carboxylate

Conditions	Yield
With tert.-butylnitrite; toluene-4-sulfonic acid In acetonitrile at 0 - 20℃; for 8h;	59%
Stage #1: ethyl 5-amino-1-benzofuran-2-carboxylate With tert.-butylnitrite; toluene-4-sulfonic acid In acetonitrile at 0℃; for 8h; Sandmeyer Reaction; Stage #2: triphenyl phosphite In acetonitrile at 0.25℃; for 8h; Sandmeyer Reaction;	58%

carbon monoxide (201230-82-2) + cyclobutanone O-(4-(trifluoromethyl)benzoyl) oxime + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → C16H16N2O4

Conditions	Yield
With copper(l) chloride; 4,4',4-tri-tert-butyl-2,2':6',2-terpyridine at 20℃; Irradiation; chemoselective reaction;	57%

ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) + trifluoromethylsilver → ethyl 5-(trifluoromethyl)benzofuran-2-carboxylate (575469-30-6)

Conditions	Yield
Stage #1: ethyl 5-amino-1-benzofuran-2-carboxylate With hydrogenchloride In water at 0℃; for 0.0833333h; Inert atmosphere; Schlenk technique; Stage #2: With tert.-butylnitrite at 0℃; for 0.25h; Inert atmosphere; Schlenk technique; Stage #3: trifluoromethylsilver at -78 - 20℃; for 4h; Inert atmosphere; Schlenk technique;	55%
Stage #1: ethyl 5-amino-1-benzofuran-2-carboxylate With hydrogenchloride In water at 0℃; for 0.0833333h; Sandmeyer Reaction; Schlenk technique; Stage #2: With tert.-butylnitrite In water at -196 - 20℃; Sandmeyer Reaction; Schlenk technique; Inert atmosphere; Stage #3: trifluoromethylsilver In water at -78 - 20℃; for 5h; Sandmeyer Reaction; Schlenk technique; Inert atmosphere;	55%

Se-(difluoromethyl) 4-methylbenzenesulfonoselenoate + ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 5-((difluoromethyl)selanyl)benzofuran-2-carboxylate

Conditions	Yield
Stage #1: ethyl 5-amino-1-benzofuran-2-carboxylate With rose bengal; toluene-4-sulfonic acid In dimethyl sulfoxide for 0.0833333h; Sealed tube; Stage #2: Se-(difluoromethyl) 4-methylbenzenesulfonoselenoate With tert.-butylnitrite In dimethyl sulfoxide at 20℃; for 10h; Irradiation;	51%

ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → ethyl 5-fluoro-1H-benzofuran-2-carboxylate (93849-31-1)

Conditions	Yield
With hydrogenchloride; tetrafluoroboric acid; sodium nitrite In water at 0℃; for 1h;	45%

ethyl 5-amino-1-benzofuran-2-carboxylate (174775-48-5) → C11H10(2)HNO3

Conditions	Yield
With chloro(cycloocta-1,5-diene)(1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene)iridium; deuterium In dichloromethane at 50℃; under 760.051 Torr; for 12h; Reagent/catalyst; Sealed tube; Inert atmosphere; regioselective reaction;	45%

Upstream product

• 90-02-8 salicylaldehyde 
• 2725-81-7 6-nitrocoumarin 
• 50396-49-1 3-(2-hydroxy-5-nitrophenyl)acrylic acid 
• 10242-12-3 5-nitrobenzofuran-2-carboxylic acid 
• 97-51-8 5-Nitrosalicylaldehyde 
• 69604-00-8 ethyl 5-nitrobenzo[d]furan-2-carboxylate 

Downstream Products

• 294174-61-1 5-{4-[bis-(2-chloro-ethyl)-amino]-benzoylamino}-benzofuran-2-carboxylic acid ethyl ester 
• 93849-31-1 ethyl 5-fluoro-1H-benzofuran-2-carboxylate 
• 163521-12-8 vilazodone 
• 163521-19-5 5-{4-[4-(5-cyano-1H-indol-3-yl)butyl]piperazin-1-yl}benzofuran-2-carboxylic acid 
• 163521-11-7 5-(4-[4-(5-cyano-3-indolyl)butyl]-1-piperazinyl)benzofuran-2-carboxylic acid ethyl ester 
• 89197-62-6 5-fluorobenzofuran-2-carboxylic acid 
• 294174-66-6 5-[bis-(2-chloro-ethyl)-amino]-benzofuran-2-carboxylic acid ethyl ester 
• 294174-44-0 5-{4-[bis-(2-chloro-ethyl)-amino]-benzoylamino}-benzofuran-2-carboxylic acid 
• 741262-62-4 2-hydroxymethyl-5-aminobenzofuran 
• 929193-49-7 ethyl 5-iodobenzofuran-2-carboxylate 

Relevant articles and documents

Synthetic method for vilazodone intermediate ethyl 5-(1-piperazinyl)-2-benzofuran-2-carboxylate

The invention relates to a synthetic method for a vilazodone intermediate, i.e., ethyl 5-(1-piperazinyl)-2-benzofuran-2-carboxylate. The key vilazodone intermediate ethyl 5-(1-piperazinyl)-2-benzofuran-2-carboxylate as shown in a formula I is prepared with 6-nitrocoumarin as a starting raw material through addition, ring opening, intramolecular ring closure, nitro reduction, piperazine ring preparation, etc. The synthetic method is simple in synthetic route, high in the yield of target products and suitable for industrial scale-up production.

Metal-free deoxygenation and reductive disilylation of nitroarenes by organosilicon reducing reagents

A metal-free deoxygenation and reductive disilylation of nitroarenes was achieved using N,N’-bis(trime-thylsilyl)-4,4’-bipyridinylidene (1) under mild and neutral reaction conditions, and a broad functional group tolerance was possible in this reaction. Mono-deoxygenation, giving a synthetically valuable N,O-bis(trimethylsilyl)phe-nylhydroxylamine (7a) as a readily available and safe phenylnitrene source from nitrobenzene, and double-deoxy-genation, giving N,N-bis(trimethylsilyl)anilines 8, were easily controlled by varying the amounts of 1 and reaction temperature as well as adding dibenzothiophene (DBTP). Reaction of 2-arylnitrobenzenes with 1 resulted in the formation of the corresponding carbazoles 14 via in situ-gen-erated phenylnitrene species derived by thermolysis of N,O-bis(trimethylsilyl)phenylhydroxylamines 7, followed by their subsequent intramolecular C H insertion. In addition, the intramolecular N N coupling reaction proceeded in the reduction of 2,2’-dinitrobiphenyl derivatives by 1, giving the corresponding benzo[c]cinnolines.

Mild and selective hydrogenation of nitro compounds using palladium nanoparticles supported on amino-functionalized mesocellular foam

We present the utilization of a heterogeneous catalyst comprised of Pd nanoparticles supported on aminopropyl-functionalized siliceous mesocellular foam (Pd0-AmP-MCF) for the selective hydrogenation of aromatic, aliphatic, and heterocyclic nitro compounds to the corresponding amines. In general, the catalytic protocol exclusively affords the desired amine products in excellent yields within short reaction times with the reactions performed at room temperature under ambient pressure of H2. Moreover, the reported Pd nanocatalyst displayed excellent structural integrity for this transformation as it could be recycled multiple times without any observable loss of activity or leaching of metal. In addition, the Pd nanocatalyst could be easily integrated into a continuous-flow device and used for the hydrogenation of 4-nitroanisole on a 2.5 g scale, where the product p-anisidine was obtained in 95% yield within 2 h with a Pd content of less than 1 ppm.