1477-50-5

Basic information

• Product Name: Indole-2-carboxylic acid
• Synonyms: NSC 16598;Indole-2-carboxylic;Indole-2-earboxylic acid ethylester;INDOLE-2-CARBOXYLIC ACID(I2CA);Indole-2-carboxylic acid,99%;Indole-2-carboxylic acid Indole-2-carboxylic acid;1H-Indole-2-carboxylic;1H-2-Indolecarboxylic acid
• CAS NO: 1477-50-5
• Molecular Formula: C9H7NO2
• Molecular Weight: 161.16
• EINECS: 216-030-4
• Product Categories: Indole/indoline/oxindole;indole derivative;Indole and Indoline;Indoles and derivatives;Carboxylic Acids;Pyrroles & Indoles;Indole;Organic acids;Amino Acids 13C, 2H, 15N;Indoles;Simple Indoles;Amino Acids & Derivatives;Indole Derivatives;Carboxylic Acids;Pyrroles & Indoles;Bioactive Small Molecules;Building Blocks;C7 to C9;Cell Biology;Chemical Synthesis;Heterocyclic Building Blocks;I;Heterocycle-Indole series
• Mol File: 1477-50-5.mol
• Article Data: 50

Chemical Properties

• Melting Point: 202-206 °C(lit.)
• Boiling Point: 287.44°C (rough estimate)
• Flash Point: 207.6 °C
• Appearance: Off-white to yellow to brown/Crystalline Powder or Crystals
• Density: 1.2480 (rough estimate)
• Vapor Pressure: 8.6E-08mmHg at 25°C
• Refractive Index: 1.5050 (estimate)
• Storage Temp.: Store below +30°C.
• Solubility: Soluble in clear yellow solution 5% in ethanol, dimethyl sulfoxi
• PKA: 4.44±0.30(Predicted)
• BRN: 124132
• CAS DataBase Reference: Indole-2-carboxylic acid(CAS DataBase Reference)
• NIST Chemistry Reference: Indole-2-carboxylic acid(1477-50-5)
• EPA Substance Registry System: Indole-2-carboxylic acid(1477-50-5)

Safety Data

• Hazard Codes: Xn,Xi
• Statements: 36/37/38-21/22
• Safety Statements: 22-24/25
• WGK Germany: 3
• RTECS: NK7882812
• HazardClass: IRRITANT
• Hazardous Substances Data: 1477-50-5(Hazardous Substances Data)

Usage

Chemical Properties

Yellow Crystalline Powder

Uses

Different sources of media describe the Uses of 1477-50-5 differently. You can refer to the following data:
1. ? ;Reactant for total synthesis of (±)-dibromophakellin and analogs1? ;Reactant for synthesis of the pyrrolizidine alkaloid (±)-trachelanthamidine2? ;Reactant for stereoselective preparation of renieramycin G analogs3? ;Reactant for preparation of spirooxoindolepyrrolidines via reduction of indole-2-carboxylic acid followed by oxidation, condensation, reduction, amidation and Kharasch radical cyclization4? ;Reactant for Pd-catalyzed cyclization5? ;Reactant for preparation of N,N′-(pentane)diylbis[indolecarboxamide] and N,N′-[phenylenebis(
2. Reactant for total synthesis of (±)-dibromophakellin and analogs, synthesis of the pyrrolizidine alkaloid (±)-trachelanthamidine, stereo selective preparation of renieramycin G analogs, preparation of spirooxoindolepyrrolidines via reduction of indole-2-carboxylic acid followed by oxidation, condensation, reduction, amidation and Kharasch radical cyclization, Pd-catalyzed cyclization and N,N?-(pentane)diylbis[indolecarboxamide] and N,N?-[phenylenebis(methylene)]bis[indolecarboxamide] derivatives.

Synthesis Reference(s)

Tetrahedron Letters, 33, p. 7961, 1992 DOI: 10.1016/S0040-4039(00)74789-7

InChI:InChI=1/C9H7NO2/c11-9(12)8-5-6-3-1-2-4-7(6)10-8/h1-5,10H,(H,11,12)/p-1

Synthetic route

2-carbethoxyindole (3770-50-1) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With potassium hydroxide In water at 120℃; for 0.5h;	99.9%
With sodium hydroxide In ethanol; water at 70℃; for 2h;	97%
With sodium hydroxide at 200℃; for 0.0166667h; Irradiation; microwave;	94%

1-(phenylsulfonyl)-1H-indole-2-carboxylic acid (40899-93-2) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With sodium t-butanolate In 1,4-dioxane at 80℃; for 3h; Inert atmosphere;	98%

o-nitrophenylpyruvic acid (5461-32-5) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With sodium dithionite In 1,4-dioxane; water for 3h; Reflux;	96%
With sodium hydroxide; sodium dithionite

indolin-2-yl carboxylic acid (16851-56-2) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With potassium tert-butylate In decane at 150℃; for 36h; Inert atmosphere; Schlenk technique;	96%
With carbon dioxide; DBN; Eosin Y In dimethyl sulfoxide at 25 - 30℃; for 48h; Irradiation;	91%
With 4-tert-Butylcatechol; oxygen In water at 20℃; for 20h; Green chemistry;	80%
With perylene diimide covalent immobilized to SiO2 nanospheres; air In N,N-dimethyl acetamide at 20℃; UV-irradiation;	67%
With oxygen at 80℃; under 760.051 Torr; for 6h; Catalytic behavior; Green chemistry; chemoselective reaction;

(4Z)-4-[(2-bromophenyl)methylene]-2-phenyl-1,3-oxazole-5-one → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With methanol; potassium carbonate; copper(I) bromide In N,N-dimethyl-formamide at 20 - 120℃; Reagent/catalyst; Temperature; Solvent;	95%

(Z)-2-phenyl-4-(2-chlorobenzylidene)-(4H)-1,3-oxazol-5-one (52900-69-3, 77435-90-6, 82301-55-1) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With methanol; copper; sodium carbonate In toluene at 20 - 120℃;	90%

2-oxo-propionic acid (127-17-3) + 2-bromoaniline (615-36-1) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With potassium phosphate; bis(N,N'-bis(2,6-diisopropylphenyl)imidazol-2-ylidene)palladium(0) In 1,4-dioxane at 100℃; for 10h; Inert atmosphere;	89%

carbon dioxide (124-38-9) + 2-bromo-1H-indole (139409-34-0) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
Stage #1: 2-bromo-1H-indole With isopropylmagnesium chloride In tetrahydrofuran at 0℃; for 0.166667h; Stage #2: With n-butyllithium In tetrahydrofuran; hexane at -20℃; for 0.5h; Stage #3: carbon dioxide In tetrahydrofuran; hexane at -20℃; for 0.5h;	85%

n-butyl 1-(pyrimidin-2-yl)-1H-indole-2-carboxylate → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With sodium ethanolate In ethanol; dimethyl sulfoxide at 100℃; for 11h; regioselective reaction;	84%

2-iodophenylamine (615-43-0) + 2-oxo-propionic acid (127-17-3) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With 1,4-diaza-bicyclo[2.2.2]octane; palladium diacetate In N,N-dimethyl-formamide at 105℃;	82%
With 1,4-diaza-bicyclo[2.2.2]octane; palladium diacetate In N,N-dimethyl-formamide at 105℃; Inert atmosphere; regioselective reaction;	82%

1H-indol-2-ylcarboxaldehyde (19005-93-7) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With oxygen; acetic anhydride; CoCl2 In 1,2-dichloro-ethane at 25℃;	77%

ethyl 2-nitrophenylpyruvate keto tautomer (784-98-5) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With 5%-palladium/activated carbon; hydrogen In water at 70℃; under 3000.3 Torr; for 8h; Temperature; Pressure;	70%
Multi-step reaction with 2 steps 1: platinum; acetic acid / Hydrogenation 2: aqueous NaOH View Scheme
With hydrogen at 50 - 60℃; under 9750.98 - 10501.1 Torr; Autoclave;

2-iodo-1H-indole (26340-49-8) + carbon dioxide (124-38-9) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
Stage #1: 2-iodo-1H-indole With n-butyllithium In tetrahydrofuran Stage #2: carbon dioxide In tetrahydrofuran	61%

2-carbethoxyindole (3770-50-1) + 1-Bromopentane (110-53-2) → Indole-2-carboxylic acid (1477-50-5) + ethyl 1-pentyl-1H-indole-2-carboxylate

Conditions	Yield
Stage #1: 2-carbethoxyindole With potassium hydroxide In water; acetone at 20℃; for 0.5h; Stage #2: 1-Bromopentane In water; acetone at 20℃; for 8h;	A 30% B 60%

6H,13H-pyrazino<1,2-a:4,5-a'>diindole-6,13-dione (58881-41-7) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With lithium hydroxide In tetrahydrofuran at 20℃; for 2h;	57%

3-(2-nitrophenyl)-2-oxopropanoic sodium salt → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With ammonium hydroxide; hydrogen In methanol pH=7.5;	56%

2-carbethoxyindole (3770-50-1) → indole (120-72-9) + Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With sodium acetate In water at 255℃; for 0.333333h; Product distribution; Irradiation; microwave; various equivalents and molarity of NaOAc; effect of temp., and time;	A 45% B 55%

(tert-Butoxycarbonylmethylene)triphenylphosphorane (86302-43-4) + 2-nitro-benzaldehyde (552-89-6) → indole (120-72-9) + Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With 1,2-dichloro-benzene; triphenylphosphine for 15h; Reflux;	A 29% B 27%

indole (120-72-9) → Indole-2-carboxylic acid (1477-50-5) + 1H-indole-3-carboxylic acid (771-50-6)

Conditions	Yield
With sodium at 230 - 250℃; im Kohlendioxyd-Strom; zuletzt bei 300grad;

2-methyl-1H-indole (95-20-5) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With potassium hydroxide beim Schmelzen;

1-acetyl-2-methylindole (37842-85-6) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With potassium hydroxide beim Schmelzen;

1,2,3,4-tetrahydrocarbazole (942-01-8) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With potassium hydroxide beim Schmelzen;

1-hydroxy-1H-indole-2-carboxylic acid (16264-71-4) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With acetic acid; zinc
With sodium amalgam

1-acetyl-3-hydroxy-indoline-2-carboxylic acid ethyl ester (105911-78-2) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With potassium hydroxide

ethyl 2-(3-N,N-diethylaminomethylindole)carboxylate (91486-86-1) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With barium dihydroxide

(2-nitro-phenyl)-glyoxylic acid (610-33-3) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
With acetic acid; zinc
With ammonia; iron(II) sulfate

2-amino-α-methoxy-cinnamic acid → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
beim Erhitzen ueber den Schmelzpunkt;
With sulfuric acid
With hydrogenchloride
beim Erhitzen ueber den Schmelzpunkt;

1-(2-indol-2-yl-2-oxo-ethyl)-pyridinium; bromide + benzaldehyde (100-52-7) → Indole-2-carboxylic acid (1477-50-5) + 1-(2-hydroxy-2-phenylethyl)pyridinium bromide (6318-99-6)

Conditions	Yield
With sodium hydroxide

(E)-3-Ureido-but-2-enoic acid ethyl ester (5435-44-9, 22243-66-9) + ethyl pyruvate phenylhydrazone (4792-54-5) → Indole-2-carboxylic acid (1477-50-5) + 2-carbethoxyindole (3770-50-1)

Conditions	Yield
at 195℃; α-form;

Yohimbine (146-48-5) → Indole-2-carboxylic acid (1477-50-5)

Conditions	Yield
at 240 - 280℃; bei der Kalischmelze;neben anderen Produkten;

diazomethane (186581-53-3, 908094-01-9) + Indole-2-carboxylic acid (1477-50-5) → indole-2-carboxylic acid methyl ester (1202-04-6)

Conditions	Yield
In diethyl ether	100%
With acetic acid In diethyl ether at -20℃;	100%
In diethyl ether at 0℃;	97%
With diethyl ether

methanol (67-56-1) + Indole-2-carboxylic acid (1477-50-5) → indole-2-carboxylic acid methyl ester (1202-04-6)

Conditions	Yield
With hydrogenchloride for 24h; Heating;	100%
Stage #1: methanol; Indole-2-carboxylic acid With sulfuric acid for 12h; Heating / reflux; Stage #2: In methanol; water pH=7;	100%
With sulfuric acid for 24h; Reflux;	99%

Indole-2-carboxylic acid (1477-50-5) + ethanol (64-17-5) → 2-carbethoxyindole (3770-50-1)

Conditions	Yield
With hydrogenchloride for 24h; Heating / reflux;	100%
With thionyl chloride In methanol at 0℃; Reflux;	99%
With thionyl chloride for 2.25h; Cooling with ice; Reflux;	99%

Indole-2-carboxylic acid (1477-50-5) + sec-Butyl-(2-piperazin-1-yl-pyridin-3-yl)-amine → 1-(indolyl-2-carbonyl)-4-<3-<(1-methylpropyl)amino>-2-pyridyl>piperazine

Conditions	Yield
With N-(3-dimethylaminopropyl)-N-ethylcarbodiimide In tetrahydrofuran for 4h; Ambient temperature;	100%

Indole-2-carboxylic acid (1477-50-5) + 4-[(tert-butoxy)carbonyl]-1-[(4-methoxyphenyl)methyl]-6-(phenylmethyl)piperazin-2-one (305324-48-5) → 16F7

Conditions	Yield
Stage #1: 4-[(tert-butoxy)carbonyl]-1-[(4-methoxyphenyl)methyl]-6-(phenylmethyl)piperazin-2-one With hydrogenchloride In ethyl acetate deprotection; Stage #2: Indole-2-carboxylic acid With 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine Acylation;	100%

Indole-2-carboxylic acid (1477-50-5) + 3-Phenyl-2-propyn-1-ol (1504-58-1) → 3-phenylprop-2-yn-1-yl 1H-indole-2-carboxylate

Conditions	Yield
Stage #1: Indole-2-carboxylic acid With dicyclohexyl-carbodiimide In dichloromethane at 0℃; for 0.166667h; Stage #2: 3-Phenyl-2-propyn-1-ol With dmap In dichloromethane at 0℃; for 2h;	100%

Indole-2-carboxylic acid (1477-50-5) + methyl 4-(1-(N-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine-3-carboxamido)cyclopropyl)benzoate dihydrochloride → methyl 4-(1-(5-(1H-indole-2-carbonyl)-N-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine-3-carboxamido)cyclopropyl)benzoate

Conditions	Yield
Stage #1: Indole-2-carboxylic acid With triethylamine; N-[(dimethylamino)-3-oxo-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl-methylene]-N-methylmethanaminium hexafluorophosphate In N,N-dimethyl-formamide for 0.25h; Stage #2: methyl 4-(1-(N-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine-3-carboxamido)cyclopropyl)benzoate dihydrochloride In N,N-dimethyl-formamide for 1h;	100%

Indole-2-carboxylic acid (1477-50-5) + methyl iodide (74-88-4) → methyl 1-methyl-1H-indole-2-carboxylate (37493-34-8)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 80℃; Inert atmosphere;	99%
Stage #1: Indole-2-carboxylic acid With sodium hydride In N,N-dimethyl-formamide at 20℃; for 1h; Metallation; Stage #2: methyl iodide In N,N-dimethyl-formamide at 20℃; for 5h; Alkylation;	72.4%
In N-methyl-acetamide	1.70 g (72.4%)

Indole-2-carboxylic acid (1477-50-5) + benzylamine (100-46-9) → N-benzyl-1H-indole-2-carboxamide (69808-76-0)

Conditions	Yield
With Bromotrichloromethane; 4-(diphenylphosphino)-benzyltrimethylammonium bromide; triethylamine In tetrahydrofuran; dichloromethane at 60℃; for 6h; Inert atmosphere;	99%
Stage #1: Indole-2-carboxylic acid With benzotriazol-1-ol; dicyclohexyl-carbodiimide In tetrahydrofuran at 0℃; for 0.5h; Stage #2: benzylamine In tetrahydrofuran at 20℃; for 24h;	95%
With 6-chloro-3-((dimethylamino)(dimethyliminio)methyl)-1H-benzo[d][1,2,3]triazol-3-ium-1-olatehexafluorophosphate(V) In N,N-dimethyl-formamide at 20℃;	74%
With (benzotriazo-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate; triethylamine In N,N-dimethyl-formamide at 25℃; for 4h;	70%

Indole-2-carboxylic acid (1477-50-5) + iodobenzene (591-50-4) → 1-phenyl-1H-indole (16096-33-6)

Conditions	Yield
With copper(I) oxide; potassium phosphate In 1-methyl-pyrrolidin-2-one at 160℃; for 12h; Reagent/catalyst; Solvent; Temperature; Inert atmosphere; Schlenk technique;	99%

tert-butyl (3S)-3-(methylamino)pyrrolidine-1-carboxylate (147081-59-2) + Indole-2-carboxylic acid (1477-50-5) → tert-butyl (3S)-3-[1H-indole-2-carbonyl(methyl)amino]pyrrolidine-1-carboxylate

Conditions	Yield
With 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In tetrahydrofuran at 20℃; for 12h;	99%

Indole-2-carboxylic acid (1477-50-5) + N,O-dimethylhydroxylamine*hydrochloride (6638-79-5) → N-methoxy-N-methyl-1H-indole-2-carboxamide (156571-69-6)

Conditions	Yield
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine In dichloromethane at 0 - 20℃; for 12h;	98.3%
Stage #1: Indole-2-carboxylic acid; N,O-dimethylhydroxylamine*hydrochloride With triethylamine In dichloromethane for 0.0833333h; Stage #2: With dicyclohexyl-carbodiimide In dichloromethane for 3h;	96%
With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; triethylamine In dichloromethane at 0 - 20℃; for 4h;	87%

Indole-2-carboxylic acid (1477-50-5) → Indole-2-carbonyl chloride (58881-45-1)

Conditions	Yield
With oxalyl dichloride; N,N-dimethyl-formamide In dichloromethane at 40℃; for 1.5h;	98%
With thionyl chloride In diethyl ether at 20℃; for 12h;	96%
With thionyl chloride In dichloromethane at 70℃; for 2h;	95%

Indole-2-carboxylic acid (1477-50-5) + ethyl β-alaninate hydrochloride (4244-84-2) → 3-[(1H-indole-2-carbonyl)amino]propionic acid ethyl ester (68724-78-7)

Conditions	Yield
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dichloromethane at 0 - 20℃; for 24h;	98%
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dichloromethane at 0 - 20℃; for 24h; Condensation;	95%
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In N,N-dimethyl-formamide at 0 - 20℃; for 24h; Inert atmosphere;	90%

Indole-2-carboxylic acid (1477-50-5) + N-methyl-1-naphthalenemethylamine hydrochloride (65473-13-4) → 1H-indole-2-carboxylic acid methyl-naphthalen-1-ylmethyl-amide

Conditions	Yield
With 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; triethylamine In dichloromethane at 20℃; for 4.5h; Condensation;	98%

Indole-2-carboxylic acid (1477-50-5) + 4-Aminobutanol (13325-10-5) → N-(4-hydroxybutyl)-1H-indole-2-carboxamide (600709-74-8)

Conditions	Yield
With 1,1'-carbonyldiimidazole In tetrahydrofuran; N,N-dimethyl-formamide at 20℃;	98%
Stage #1: Indole-2-carboxylic acid With 1-hydroxybenzotriazol-hydrate; dicyclohexyl-carbodiimide In dichloromethane at 20℃; Stage #2: 4-Aminobutanol In dichloromethane at 20℃;	93%
Stage #1: Indole-2-carboxylic acid With benzotriazol-1-ol; dicyclohexyl-carbodiimide In dichloromethane at 0 - 20℃; Inert atmosphere; Stage #2: 4-Aminobutanol In dichloromethane at 20℃; for 16h; Inert atmosphere;	93%

Indole-2-carboxylic acid (1477-50-5) + 3-amino-propionic acid ethyl ester (924-73-2) → 3-[(1H-indole-2-carbonyl)amino]propionic acid ethyl ester (68724-78-7)

Conditions	Yield
With 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dichloromethane	98%
With benzotriazol-1-ol; triethylamine; dicyclohexyl-carbodiimide In 1,4-dioxane; dichloromethane; N,N-dimethyl-formamide at 20℃;

Indole-2-carboxylic acid (1477-50-5) + 1-phenylmethylpiperazine (2759-28-6) → 2-(4-benzylpiperazin-1-yl)carbonyl indole hydrochloride

Conditions	Yield
With thionyl chloride In toluene	98%

Indole-2-carboxylic acid (1477-50-5) + N-[(4-methoxyphenyl)methyl]prop-2-yn-1-amine (98729-72-7) → N-(4-methoxybenzyl)-N-propargyl-1H-indole-2-carboxamide (1250829-42-5)

Conditions	Yield
Stage #1: Indole-2-carboxylic acid With oxalyl dichloride In dichloromethane; N,N-dimethyl-formamide at 20℃; for 2h; Reflux; Stage #2: N-(4-methoxybenzyl)prop-2-yn-1-amine With triethylamine In dichloromethane at 0 - 20℃; for 1h;	98%

Indole-2-carboxylic acid (1477-50-5) + N-(4-methylbenzyl)prop-2-yn-1-amine (892594-94-4) → N-(4-methylbenzyl)-N-propargyl-1H-indole-2-carboxamide (1250829-43-6)

Conditions	Yield
Stage #1: Indole-2-carboxylic acid With oxalyl dichloride In dichloromethane; N,N-dimethyl-formamide at 20℃; for 2h; Reflux; Stage #2: N-(4-methylbenzyl)prop-2-yn-1-amine With triethylamine In dichloromethane at 0 - 20℃; for 1h;	98%

Indole-2-carboxylic acid (1477-50-5) + 2,2-dimethoxyethylamine (22483-09-6) → N-(2,2-dimethoxyethyl)-1H-indole-2-carboxamide

Conditions	Yield
With (benzotriazo-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate; triethylamine In N,N-dimethyl-formamide at 25℃; for 2h;	98%
With 1,1'-carbonyldiimidazole In 1,4-dioxane at 70℃; for 3h;

Indole-2-carboxylic acid (1477-50-5) → 3,3-dichloro-2,3-dihydro-1H-indol-2-one (39033-45-9)

Conditions	Yield
With 1,3-dichloro-5,5-dimethylhydantoin In ethyl acetate at 20℃;	98%
Multi-step reaction with 2 steps 1: dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride / dichloromethane / 24 h / 20 °C 2: 1,3-dichloro-5,5-dimethylhydantoin / ethyl acetate / 20 °C View Scheme

Indole-2-carboxylic acid (1477-50-5) + methyl (2S)-2-amino-3-hydroxypropanoate hydrochloride (5680-80-8) → methyl (1H-indole-2-carbonyl)-L-serinate

Conditions	Yield
With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; triethylamine In dichloromethane at 0 - 20℃; for 18h;	98%
With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; triethylamine In dichloromethane at 0 - 20℃; for 24h;	98%

Indole-2-carboxylic acid (1477-50-5) + para-nitrophenyl bromide (586-78-7) → 1-(4-nitrophenyl)-1H-indole-2-carboxylic acid (65439-85-2)

Conditions	Yield
With quebrachitol; copper; caesium carbonate In water; dimethyl sulfoxide at 100℃; Ullmann Condensation; Inert atmosphere; Green chemistry;	98%
With copper; caesium carbonate; methyl-alpha-D-glucopyranoside In water; dimethyl sulfoxide at 100℃; Sealed tube; Green chemistry;	91%

Indole-2-carboxylic acid (1477-50-5) + m-bromobenzoic acid (585-76-2) → 1-(3-carboxyphenyl)-1H-indole-2-carboxylic acid

Conditions	Yield
With quebrachitol; copper; caesium carbonate In water; dimethyl sulfoxide at 100℃; Ullmann Condensation; Inert atmosphere; Green chemistry;	98%

Indole-2-carboxylic acid (1477-50-5) → indole-2,3-dione (91-56-5)

Conditions	Yield
With oxygen; Rose Bengal lactone In water; N,N-dimethyl-formamide for 48h; Inert atmosphere; Irradiation;	98%

Indole-2-carboxylic acid (1477-50-5) + (S)-serine methyl ester (2788-84-3) → methyl (1H-indole-2-carbonyl)-L-serinate

Conditions	Yield
With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; triethylamine In dichloromethane for 18h;	98%

Indole-2-carboxylic acid (1477-50-5) + (E)-methyl 2-((methylamino)methyl)-3-phenylacrylate (1021167-64-5) → C21H20N2O3

Conditions	Yield
Stage #1: Indole-2-carboxylic acid With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dimethyl sulfoxide at 20℃; for 0.416667h; Michael Addition; Inert atmosphere; Schlenk technique; Stage #2: (E)-methyl-2-((methylamino)methyl)-3-phenylacrylate With triethylamine In dimethyl sulfoxide at 20℃; for 3h; Michael Addition; Inert atmosphere; Schlenk technique;	98%

Upstream product

• 37842-85-6 1-acetyl-2-methylindole 
• 100-52-7 benzaldehyde 
• 5461-32-5 o-nitrophenylpyruvic acid 
• 64-19-7 acetic acid 
• 26340-49-8 2-iodo-1H-indole 
• 124-38-9 carbon dioxide 
• 3770-50-1 2-carbethoxyindole 
• 110-53-2 1-Bromopentane 
• 120-72-9 indole 
• 95-20-5 2-methyl-1H-indole 
• 942-01-8 1,2,3,4-tetrahydrocarbazole 
• 16264-71-4 1-hydroxy-1H-indole-2-carboxylic acid 
• 105911-78-2 1-acetyl-3-hydroxy-indoline-2-carboxylic acid ethyl ester 
• 91486-86-1 ethyl 2-(3-N,N-diethylaminomethylindole)carboxylate 

Downstream Products

• 1202-04-6 indole-2-carboxylic acid methyl ester 
• 3770-50-1 2-carbethoxyindole 
• 15849-25-9 3-(3-phenyl-propyl)-indole 
• 703-80-0 3-acetylindole 
• 17537-64-3 1,3-diacetyl-1H-indole 
• 10441-26-6 N-acetyl-indole-2-carboxylic acid 
• 69808-71-5 1H-indole-2-carboxylic acid methylamide 
• 271-26-1 3H-indole 
• 120-72-9 indole 
• 83-34-1 3-Methylindole 
• 58881-45-1 Indole-2-carbonyl chloride 
• 28737-33-9 3-bromo-1H-indole-2-carboxylic acid 
• 98591-49-2 3,5-dibromo-indole-2-carboxylic acid 
• 28737-35-1 3-nitro-indole-2-carboxylic acid 

Relevant articles and documents

Improved preparation method of indole-2-formic acid as starting material of perindopril

The invention discloses an improved preparation method of indole-2-formic acid by using perindopril as a starting raw material, which comprises the following steps: S1, taking 2-bromobenzaldehyde and ethyl acetate as raw materials, under the action of sodium ethoxide, carrying out Claisen-Schmidt condensation reaction to synthesize ethyl 2-bromocinnamate; s2, carrying out cyclization reaction on the ethyl 2-bromocinnamate in an amide solvent by using cuprous halide as a coupling catalyst and sodium azide as a nitrogen source to synthesize the indole-2-formic acid in one pot. According to the invention, 2-bromobenzaldehyde is used as a raw material for preparation, ethyl 2-bromocinnamate is firstly prepared, then cuprous halide is used as a coupling catalyst, sodium azide is used as a nitrogen source, cyclization reaction is carried out in an amide solvent, indole-2-formic acid is synthesized in one pot, and the HPLC content is 99% or above.

MnOx/catechol/H2O: A cooperative catalytic system for aerobic oxidative dehydrogenation of N-heterocycles at room temperature

Amorphous manganese oxide doped by Na+ ion (Na-AMO) was successfully prepared and found to be an efficient heterogeneous catalyst in aerobic oxidative dehydrogenation of N-heterocycles, cooperate with catechol. Na-AMO was fully characterized by XRD, XPS BET H2-TPR, CO2-TPD FT-IR, TEM, SEM and had rich amounts of surface absorbed active oxygen species which are responsible for superior catalytic performance. The synergistic interaction between Na-AMO and catechol makes catalytic system efficient and tolerant, which offers various N-heterocycles in good to excellent yields under mild conditions.

Aerobic oxidative dehydrogenation of N-heterocycles over OMS-2-based nanocomposite catalysts: Preparation, characterization and kinetic study

OMS-2-based nanocomposites doped with tungsten were prepared for the first time and their remarkably enhanced catalytic activity and recyclability in aerobic oxidative dehydrogenation of N-heterocycles were examined in detail. Many tetrahydroquinoline derivatives and a broad range of other N-heterocycles could be tolerated by the catalytic system using a biomass-derived solvent as a reaction medium. Newly generated mixed crystal phases, noticeably enhanced surface areas and labile lattice oxygen of the OMS-2-based nanocomposite catalysts might contribute to their excellent catalytic performance. Moreover, a kinetic study was extensively performed which concluded that the dehydrogenation of 1,2,3,4-tetrahydroquinoline is a first-order reaction, and the apparent activation energy is 29.66 kJ mol-1