496-16-2

Basic information

• Product Name: 2,3-Dihydrobenzofuran
• Synonyms: 2,3-Dihydro-1-benzofuran;2,3-dihydro-benzofura;Coumaran (2,3-dihydrobenzofuran);Dihydrobenzofuran;Dihydrocoumarone;Kumaran;2,3-DIHYDROBENZO[B]FURAN;2,3-DIHYDROBENZOFURAN
• CAS NO: 496-16-2
• Molecular Formula: C₈H₈O
• Molecular Weight: 120.15
• EINECS: 207-817-3
• Product Categories: Fluorobenzene;Benzodiozoles, Benzodioxines & Benzodioxepines;Furan&Benzofuran;Benzodiozoles, Benzodioxines & Benzodioxepines
• Mol File: 496-16-2.mol

Chemical Properties

• Melting Point: -21°C
• Boiling Point: 188-189 °C(lit.)
• Flash Point: 152 °F
• Appearance: colorless to light yellow liquid
• Density: 1.065 g/mL at 25 °C(lit.)
• Vapor Pressure: 0.836mmHg at 25°C
• Refractive Index: n20/D 1.549(lit.)
• Storage Temp.: Store below +30°C.
• Solubility: alcohol: soluble
• Merck: 14,2559
• BRN: 111928
• CAS DataBase Reference: 2,3-Dihydrobenzofuran(CAS DataBase Reference)
• NIST Chemistry Reference: 2,3-Dihydrobenzofuran(496-16-2)
• EPA Substance Registry System: 2,3-Dihydrobenzofuran(496-16-2)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 23-24/25-26
• WGK Germany: 3
• TSCA: Yes
• Hazardous Substances Data: 496-16-2(Hazardous Substances Data)

Usage

Description

2,3-Dihydrobenzofuran is an organic compound that features a benzene ring fused with an oxygen-containing furan ring. It is a versatile intermediate in organic synthesis and possesses unique structural properties that make it valuable in the development of various pharmaceuticals and chemical compounds.

Uses

Used in Pharmaceutical Industry:
2,3-Dihydrobenzofuran is used as a key intermediate in the synthesis of tricyclic compounds, which are essential in the development of complex drug molecules. Its unique structure allows for the formation of multiple bonds and functional groups, facilitating the creation of diverse therapeutic agents.
Used in Antitumor Agent Synthesis:
In the field of oncology, 2,3-dihydrobenzofuran is utilized as a precursor for the synthesis of benzofuran sulfonylureas, a class of compounds with demonstrated antitumor activity. These agents have the potential to target and inhibit the growth of cancer cells, offering new treatment options for patients.
Used in HIV Treatment:
2,3-Dihydrobenzofuran is also employed in the synthesis of HIV protease inhibitor amino acid hydroxyethylenesulfonyl. These compounds are designed to inhibit the activity of the HIV protease enzyme, which is crucial for the replication of the virus. By blocking this enzyme, the spread of HIV can be slowed, providing an effective treatment strategy for those living with the disease.
Used in Matrix Metalloproteinase Inhibition:
Furthermore, 2,3-dihydrobenzofuran serves as a starting material for the synthesis of aryl sulfinyl isoxime hydroxamic acid, a class of matrix metalloproteinase (MMP) inhibitors. MMPs are enzymes involved in the breakdown of extracellular matrix proteins, and their overexpression is associated with various pathological conditions, including cancer and tissue remodeling disorders. Inhibiting MMP activity with 2,3-dihydrobenzofuran-derived compounds can help manage these conditions and potentially reduce disease progression.

Synthetic route

1-benzofurane (271-89-6) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With methanol; palladium diacetate; 4,4,5,5-tetramethyl-[1,3,2]-dioxaboralane In dichloromethane at 25℃; for 12h; Sealed tube; Inert atmosphere; chemoselective reaction;	99%
With hydrogen In methanol at 80 - 90℃; under 750.075 - 22502.3 Torr; Reagent/catalyst; Autoclave;	97.8%
With ethanol; (BQ‑NCOP)IrHCl; sodium t-butanolate at 60℃; for 5h; Inert atmosphere; Schlenk technique; Sealed tube; chemoselective reaction;	96%

2-(2-iodophenyl)ethan-1-ol (26059-40-5) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With copper(l) iodide; sodium t-butanolate In N,N-dimethyl-formamide at 20℃; for 0.0833333h; Schlenk technique; Inert atmosphere; Molecular sieve;	99%
Multi-step reaction with 3 steps 1.1: triphenylphosphine; iodine; 1H-imidazole / tetrahydrofuran / 2 h / 0 °C / Inert atmosphere; Darkness 2.1: silver(l) oxide / N,N-dimethyl-formamide / 0 °C / Inert atmosphere 2.2: 0 - 20 °C / Inert atmosphere 3.1: n-butyllithium / tetrahydrofuran; hexane / 1 h / -78 - 20 °C / Inert atmosphere View Scheme

2-(2-chlorophenyl)-1-ethanol (19819-95-5) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With Ru/Al2O3; potassium carbonate In N,N-dimethyl-formamide at 60℃; for 1.5h; Temperature; Microwave irradiation;	96.2%
With copper(l) iodide; 8-quinolinol; caesium carbonate In 5,5-dimethyl-1,3-cyclohexadiene at 20 - 120℃; Inert atmosphere;	82%
With racemic-2-(di-tert-butylphosphino)-1,1′-binaphthyl; palladium diacetate; caesium carbonate In toluene at 50℃; for 23h;	72%
With racemic-2-(di-tert-butylphosphino)-1,1′-binaphthyl; palladium diacetate; caesium carbonate In toluene at 50℃; for 23h;	72%
With potassium phosphate; C22H28NP; palladium diacetate In toluene at 60℃; for 20h;	51 % Chromat.

2-bromophenylethyl alcohol (1074-16-4) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With copper(l) iodide; lithium tert-butoxide In 1,4-dioxane at 100℃;	96%
With racemic-2-(di-tert-butylphosphino)-1,1′-binaphthyl; palladium diacetate; caesium carbonate In toluene at 50℃; for 26h;	87%
With racemic-2-(di-tert-butylphosphino)-1,1′-binaphthyl; palladium diacetate; caesium carbonate In toluene at 50℃; for 26h;	87%

2-(2-hydroxyphenyl)ethanol (7768-28-7) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With sodium methylate In carbonic acid dimethyl ester; acetonitrile for 2h; Inert atmosphere;	95%
With 1,8-diazabicyclo[5.4.0]undec-7-ene; carbonic acid dimethyl ester at 90℃; for 8h; Reagent/catalyst; Time;	93%
Stage #1: 2-(2-hydroxyphenyl)ethanol With sodium hydride In mineral oil at 20℃; for 0.166667h; Inert atmosphere; Stage #2: With trimethyl phosphite In mineral oil at 20℃; for 24h; Inert atmosphere;	90%

1-benzofurane (271-89-6) + 1,4,4a,9a-tetrahydro-fluorene (52652-40-1) → 2,3-Dihydrobenzofuran (496-16-2) + 9H-fluorene (86-73-7)

Conditions	Yield
palladium on activated carbon at 250℃; for 2h;	A 92% B 95%

1-benzofurane (271-89-6) + 1,2,3,4-tetrahydro-9H-fluorene (17057-95-3) → 2,3-Dihydrobenzofuran (496-16-2) + 9H-fluorene (86-73-7)

Conditions	Yield
	A 92% B n/a

1-iodo-2-(2-iodo-ethoxy)-benzene → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
Stage #1: 1-iodo-2-(2-iodo-ethoxy)-benzene With isopropylmagnesium chloride In tetrahydrofuran at -30℃; for 1h; Stage #2: In tetrahydrofuran at 25℃; for 2h; Stage #3: In tetrahydrofuran	87%

2-(2-Bromoethyl)phenol (57027-75-5) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With potassium hydroxide In ethanol for 3h; Heating;	86%
With sodium hydroxide; benzene
With water

2-(2-bromophenoxy)ethyl 4-methylbenzenesulfonate (94897-00-4) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With copper(l) iodide; lithium methanolate; magnesium In tetrahydrofuran at 0℃; for 24h; Inert atmosphere; Schlenk technique;	85%

2-(2-hydroxyphenyl)ethanol (7768-28-7) + Vilsmeier reagent (3724-43-4, 149409-22-3) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With triethylamine In dichloromethane Ambient temperature;	80%

1-(2-bromoethoxy)-2-iodobenzene (57056-94-7) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
Stage #1: 1-(2-bromoethoxy)-2-iodobenzene With isopropylmagnesium chloride In tetrahydrofuran at -30℃; for 1h; Stage #2: In tetrahydrofuran at 25℃; for 2h; Stage #3: In tetrahydrofuran	79%

2-bromophenyl 2-chloroethyl ether (64010-12-4) → 2,3-Dihydrobenzofuran (496-16-2) + 2-hydroxybromobenzene (95-56-7) + phenol (108-95-2)

Conditions	Yield
With magnesium; ethylene dibromide In tetrahydrofuran	A 76% B n/a C n/a

5-methyl-1,10-phenanthroline (3002-78-6) + 2-bromophenylethyl alcohol (1074-16-4) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With CuI; caesium carbonate In dodecane; toluene	72%

1-(2-bromoethoxy)-2-bromobenzene (18800-28-7) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With n-butyllithium In tetrahydrofuran; hexane at -100 - -95℃; for 0.5h;	69%
With diethyl ether; sodium

benzofuran-2(3H)-one (553-86-6) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With aluminium(III) triflate; tris(2,4-pentanedionato)ruthenium(III); hydrogen; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 160℃; under 45603.1 Torr; for 12h; Autoclave;	65%
Multi-step reaction with 2 steps 1: Lawesson's reagent / toluene / Heating 2: Raney nickel / diethyl ether / 1.) -15 deg C, 2.) -10 deg C, 2 min View Scheme

2-(2-iodophenyl)ethyl tert-butyl peroxide (1592933-65-7) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With n-butyllithium In tetrahydrofuran; hexane at -78 - 20℃; for 1h; Inert atmosphere;	58%

2-(2-hydroxyphenyl)ethanol (7768-28-7) + carbonic acid dimethyl ester (616-38-6) → 2,3-Dihydrobenzofuran (496-16-2) + 2-(2'-hydrophenyl)ethyl methyl carbonate

Conditions	Yield
With sodium methylate for 7h; Reflux; Inert atmosphere;	A 55% B 31%
With sodium methylate at 90℃; for 24h;	A 6% B 21%

2-aminophenethyl alcohol (5339-85-5) → 2,3-Dihydrobenzofuran (496-16-2) + 2-(2-hydroxyphenyl)ethanol (7768-28-7)

Conditions	Yield
With sulfuric acid; sodium nitrite at 0 - 50℃; for 1h;	A 35% B 50%

2-methoxyphenethyl alcohol (7417-18-7) → 2,3-Dihydrobenzofuran (496-16-2) + 2-(2-Bromoethyl)phenol (57027-75-5)

Conditions	Yield
With hydrogen bromide; acetic acid	A 36% B 46%

1-benzofurane (271-89-6) → o-Hydroxyethylbenzene (90-00-6) + 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With 15-crown-5; sodium; isopropyl alcohol In tetrahydrofuran at 0℃; for 0.0833333h; Birch Reduction; chemoselective reaction;	A 42% B 39%
With ethanol; sodium
With ethanol; sodium
With 15-crown-5; sodium In tetrahydrofuran; isopropyl alcohol; mineral oil at 0℃; for 0.0833333h; Inert atmosphere; Overall yield = 75 %; Overall yield = 45 mg;

1-bromo-2-methoxy-3-methylbenzene (52200-69-8) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With palladium(0)bis(tricyclohexylphosphine); cesium pivalate In toluene at 140℃; for 16h; Inert atmosphere; Sealed tube; Glovebox;	40%

1-benzofurane (271-89-6) → 2,3-Dihydrobenzofuran (496-16-2) + 4,7-dihydrobenzofuran (99636-24-5)

Conditions	Yield
With sodium In methanol; diethyl ether; ammonia for 0.166667h;	A 34% B 36%
With tetrabutylammonium tetrafluoroborate In tetrahydrofuran; water at 0℃; electrolysis (mercury cathode, platinum flag anode, silver wire reference electrode, constant current 4-32 mA cm-2); Yield given. Yields of byproduct given;

3,4-epoxy-chroman (6538-94-9) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
In cyclohexane for 6h; Ambient temperature; Irradiation;	36%

(Trimethylsilyl)(o-methoxyphenyl)methanol (75311-63-6) → 1-benzofurane (271-89-6) + 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
In benzene at 600℃;	A 16% B 28%

[(2-Methoxy-phenyl)-phenylmethanesulfonyl-methylene]-triphenyl-λ5-phosphane (134749-74-9) → 2,3-Dihydrobenzofuran (496-16-2) + (E)-2-methoxystilbene (52805-92-2) + (Z)-1-(2-methoxyphenyl)-2-phenylethene (1898-14-2) + 1,1'-(1,2-ethanediyl)bisbenzene (103-29-7)

Conditions	Yield
at 600℃; under 0.001 - 0.1 Torr; for 1h; Yields of byproduct given. Title compound not separated from byproducts;	A 7% B n/a C n/a D 11 % Spectr.

2-Phenoxyethanol (122-99-6) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With zinc(II) chloride
With manganese(ll) chloride; zinc(II) chloride at 200℃; for 3h; Temperature;

1-(2-bromoethoxy)-2-chlorobenzene (18800-26-5) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With diethyl ether; sodium

2-aminophenethyl alcohol (5339-85-5) → 2,3-Dihydrobenzofuran (496-16-2)

Conditions	Yield
With sulfuric acid; sodium nitrite Erwaermen der Diazoniumsalz-Loesung mit Natiumhydrogencabonat;
Multi-step reaction with 2 steps 1: 50 percent / aq. sodium nitrite, conc. sulfuric acid / 1 h / 0 - 50 °C 2: 75 percent / alumina-silica / 1,2-dimethoxy-ethane / 1 h / 250 °C View Scheme

2,3-Dihydrobenzofuran (496-16-2) → 5-bromo-2,3-dihydrobenzo[b]furan (66826-78-6)

Conditions	Yield
With bromine	100%
With iron(III) chloride; N-Bromosuccinimide; 1-butyl-3-methylimidazolium trifluoromethanesulfonimide In toluene at 40℃; regioselective reaction;	98%
With bromine In dichloromethane for 0.5h; Ambient temperature;	96%

2,3-Dihydrobenzofuran (496-16-2) + N,N-dimethyl-formamide (68-12-2, 33513-42-7) → 2,3-dihydro-benzofuran-5-carbaldehyde (55745-70-5)

Conditions	Yield
With trichlorophosphate at 70 - 90℃; for 9.5h;	100%
With trichlorophosphate at 70 - 90℃; for 9.5h;	100%
Stage #1: 2.3-dihydrobenzofuran; N,N-dimethyl-formamide With trichlorophosphate at 30 - 70℃; Stage #2: With water In N,N-dimethyl-formamide at 20℃; for 1h;	98%

2,3-Dihydrobenzofuran (496-16-2) → 2,3-dihydro-benzofuran-5-carbaldehyde (55745-70-5)

Conditions	Yield
With trichlorophosphate In water; N,N-dimethyl-formamide	100%
With trichlorophosphate In water; N,N-dimethyl-formamide	100%
With sodium hydrogencarbonate; trichlorophosphate In N,N-dimethyl-formamide	94%
Multi-step reaction with 2 steps 1: 100 percent / Br2 2: 98 percent / n-BuLi / tetrahydrofuran; hexane / -78 - 20 °C View Scheme

2,3-Dihydrobenzofuran (496-16-2) → 2,3-dihydrobenzofuran-5-sulfonyl chloride (115010-11-2)

Conditions	Yield
Stage #1: 2.3-dihydrobenzofuran With sulfur trioxide-N,N-dimethylformamide complex In 1,2-dichloro-ethane at 85℃; for 1h; Stage #2: With thionyl chloride In 1,2-dichloro-ethane at 20 - 75℃; for 1h;	100%
Stage #1: 2.3-dihydrobenzofuran With sulfur trioxide-N,N-dimethylformamide complex In 1,2-dichloro-ethane at 85℃; for 1h; Stage #2: With thionyl chloride In 1,2-dichloro-ethane at 20 - 75℃; for 1h;	100%
In 1,2-dichloro-ethane	94%

2,3-Dihydrobenzofuran (496-16-2) + acetyl chloride (75-36-5) → 1-(2,3-dihydrobenzofuran-5-yl)ethanone (90843-31-5)

Conditions	Yield
aluminum (III) chloride In dichloromethane at -10℃; for 0.5h;	99%
With aluminum (III) chloride In dichloromethane at -10℃; for 0.5h;	99%
With aluminum (III) chloride In dichloromethane at -10℃; for 3h;	97%

2,3-Dihydrobenzofuran (496-16-2) → 5-iodo-2,3-dihydro-1-benzofuran (132464-84-7)

Conditions	Yield
With N-iodo-succinimide; silver(I) triflimide In dichloromethane at 36℃; for 1h; Darkness;	99%
With indium(III) triflate; N-iodo-succinimide In acetonitrile at 23℃; for 8h; Inert atmosphere; Darkness;	92%
With iron(III) chloride; N-iodo-succinimide; 1-butyl-3-methylimidazolium trifluoromethanesulfonimide at 36℃; for 1h; Inert atmosphere;	91%

triethylsilane (617-86-7) + 2,3-Dihydrobenzofuran (496-16-2) → triethyl-(2-ethyl-phenoxy)-silane

Conditions	Yield
With tris(pentafluorophenyl)borate In dichloromethane at 20℃; for 20h; silylation;	99%
With tris(pentafluorophenyl)borate In dichloromethane at 20℃; for 20h; Reduction; dehydrocondensation;	99%

2,3-Dihydrobenzofuran (496-16-2) + 1,2-dichloro-ethane (107-06-2) → 2,3-dihydrobenzofuran-5-sulfonyl chloride (115010-11-2)

Conditions	Yield
With thionyl chloride In water	99%

2,3-Dihydrobenzofuran (496-16-2) + 2-trimethylsilyl ethane sulfonic acid azide (871949-46-1) → C13H21NO3SSi

Conditions	Yield
Stage #1: 2.3-dihydrobenzofuran; 2-trimethylsilyl ethane sulfonic acid azide In neat (no solvent) at -10℃; for 0.5h; Schlenk technique; Inert atmosphere; Molecular sieve; Stage #2: With C61H40F4N2O3Ru In neat (no solvent) at -10℃; for 2h; Schlenk technique; Inert atmosphere; Molecular sieve; enantioselective reaction;	99%

2,3-Dihydrobenzofuran (496-16-2) + bis(pinacol)diborane (73183-34-3) → 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzo[b]furan (402503-13-3)

Conditions	Yield
With C25H40O2P2Ru In octane at 150℃; for 12h; Inert atmosphere;	99%

2,3-Dihydrobenzofuran (496-16-2) + propionyl chloride (79-03-8) → 1-(2,3-dihydrobenzofuran-5-yl)propan-1-one (68660-11-7)

Conditions	Yield
Stage #1: propionyl chloride; aluminum (III) chloride In dichloromethane at 0℃; for 0.166667h; Inert atmosphere; Stage #2: 2.3-dihydrobenzofuran In dichloromethane at 0℃; Inert atmosphere;	98%
With aluminum (III) chloride In dichloromethane at 0 - 20℃; for 1h;	80%
With tin(IV) chloride In benzene at 30℃; for 24h; Friedel-Crafts acylation;	66%
With carbon disulfide; aluminium trichloride

2,3-Dihydrobenzofuran (496-16-2) → 2,3-dihydrobenzofuran-5-sulfonic acid

Conditions	Yield
With sulfur trioxide In nitromethane at 0℃; for 1h;	98%
With sulfur trioxide In nitromethane at 0℃;

2,3-Dihydrobenzofuran (496-16-2) → 2,3-Dihydro-benzofuran-5,7-disulfonic acid

Conditions	Yield
With sulfuric acid at 20℃; for 3600h; other reagent; other solvent; other temp;	98%
With sulfur trioxide In nitromethane at 0℃; excess of reagent;

2,3-Dihydrobenzofuran (496-16-2) + norbornene (498-66-8) → 7-(bicyclo[2.2.1]hept-2-yl)-2,3-dihydro-1-benzofuran

Conditions	Yield
With (C5H5)Y(CH2C6H4NMe2-o)2; trityl tetrakis(pentafluorophenyl)borate In toluene at 70℃; for 24h; Inert atmosphere; Glovebox; regioselective reaction;	98%

2,3-Dihydrobenzofuran (496-16-2) + benzoic acid (65-85-0) → (2,3-dihydrobenzofuran-5-yl)(phenyl)methanone (115063-19-9)

Conditions	Yield
With trifluoroacetic acid; trifluoroacetic anhydride at 20℃; for 12h; Friedel-Crafts Acylation; Inert atmosphere;	98%

2,3-Dihydrobenzofuran (496-16-2) + 4-Methoxybenzenethiol (696-63-9) → (2,3-dihydro-1-benzofuran-5-yl)(4′-methoxyphenyl)sulfane

Conditions	Yield
With tetrabutylammonium acetate for 4.5h; Electrolysis; Inert atmosphere; Sealed tube; regioselective reaction;	97%

2,3-Dihydrobenzofuran (496-16-2) + bis(2,2,2-trichloroethyl) hydrazino-1,2-dicarboxylate (38858-02-5) → 1-(5-dihydrobenzofuranyl)-1,2-hydrazinedicarboxylic acid bis(2,2,2-trichloroethyl) ester (197590-43-5)

Conditions	Yield
With zinc(II) chloride In dichloromethane at 20℃;	96.6%

2,3-Dihydrobenzofuran (496-16-2) → 5-Chloro-2,3-dihydrobenzo[b]furan (76429-69-1)

Conditions	Yield
With N-chloro-succinimide; 2,2,6,6-tetramethylpiperidin-1-oxoammonium trifluoromethanesulfonate In chloroform at 25℃; for 12h; Reagent/catalyst; Schlenk technique;	96%
With iron(III) chloride; N-chloro-succinimide; 1-butyl-3-methylimidazolium trifluoromethanesulfonimide In tetrahydrofuran at 60℃; for 18h; Inert atmosphere; regioselective reaction;	86%
With N-chloro-succinimide; zirconium(IV) chloride In dichloromethane at 20℃; for 12h;
With N-chloro-succinimide; zirconium(IV) chloride In dichloromethane at 20℃; for 12h; Conversion of starting material;
With N-chloro-succinimide; acetic acid In acetonitrile at 10 - 35℃; for 48h;	2.28 g

2,3-Dihydrobenzofuran (496-16-2) + acetic anhydride (108-24-7) → 1-(2,3-dihydrobenzofuran-5-yl)ethanone (90843-31-5)

Conditions	Yield
With Hβ zeolite (Si:Al 12.5) at 120℃; for 1.5h;	95%
With trifluoroacetic acid at 20℃; for 1.5h; Friedel-Crafts Acylation;	91%
With zinc(II) chloride at 95 - 105℃; for 10h;
With zinc(II) chloride at 95 - 105℃; for 10h;

3,5-bis(trifluoromethyl)phenyl azide + 2,3-Dihydrobenzofuran (496-16-2) → C16H11F6NO

Conditions	Yield
With chloro[5,10,15,20-tetrakis(4-dimethylamino-2,3,5,6-tetrafluorophenyl)porphyrinate]iron(III) In 1,2-dichloro-ethane at 120℃; for 12h; Schlenk technique; Inert atmosphere; Molecular sieve; regioselective reaction;	95%

2,3-Dihydrobenzofuran (496-16-2) → 2,3-dihydrobenzofuran-7-sulfonyl chloride (953408-82-7)

Conditions	Yield
In 1,2-dichloro-ethane	94%

2,3-Dihydrobenzofuran (496-16-2) → 1-(2,3-dihydrobenzofuran-5-yl)ethanone (90843-31-5)

Conditions	Yield
Stage #1: acetyl chloride With aluminum (III) chloride In dichloromethane at -10℃; for 0.25h; Stage #2: 2.3-dihydrobenzofuran In dichloromethane at -10℃; for 0.5h; Stage #3: With hydrogenchloride In dichloromethane; water at 0℃; for 2h;	94%

2,3-Dihydrobenzofuran (496-16-2) → 5,7-Dibromo-2,3-dihydrobenzofuran (123266-59-1)

Conditions	Yield
With bromine; sodium thiosulfate In dichloromethane; acetic acid	93%
With iodine pentoxide; potassium bromide In water at 20℃; for 23h; regioselective reaction;	89%
With bromine; sodium thiosulfate In chloroform	87%

2,3-Dihydrobenzofuran (496-16-2) + 5-Chlorovaleroyl chloride (1575-61-7) → 5-Chloro-1-(2,3-dihydro-1-benzofuran-5-yl)-1-pentanone

Conditions	Yield
Stage #1: 2.3-dihydrobenzofuran; aluminum (III) chloride In toluene at 20 - 30℃; for 0.5h; Stage #2: 5-Chlorovaleroyl chloride In toluene at -5 - 5℃; for 1h;	92.8%