6-bromo-2,3,4,9-tetrahydro-1H-carbazole

General procedure: T3P.(R). (50percent in EtOAc) (0.55-0.68 mmol) was added to a mixture of hydrazine (59 mg, 0.55 mmol) and ketone/aldehyde (0.55 mmol) in a microwave vial. The reaction volume was then made up to 0.5 mL with EtOAc and the vessel was sealed under air. The mixture was heated under microwave irradiation (Biotage Initiator) at 100-150 °C for 5-15 min. The solvent was evaporated under reduced pressure and the oily residue was purified by filtration through a plug of silica gel (eluent: isohexane/EtOAc, 8:2) to yield the desired indole or tetrahydrocarbazole. When the reaction was conducted on a 5 mmol scale the product (3a) was purified by precipitation from acetone/water.General procedure: A mixture of the carbonyl compound (5, 1.0 mmol), arylhydrazine (6, 1.2 mmol), and the solid acid (7, Amberlite, 1.5 g, obtained from Aldrich Chemical Co.) was refluxed in absolute ethanol (10 ml) for 8 h. The reaction was monitored by thin-layer chromatography(TLC), and upon completion the mixture was cooled to room temperature, the catalyst filtered off, and the product was washed thoroughly with ethylacetate (30 ml). The combined organics were washed with water, dried (NaGeneral procedure: A substituted phenyl hydrazine. HCl (4.61 mmol) was added to the mixture of cyclohexanone (4.61 mmol) and acetic acid (15 ml) portion wise for 30 min. The mixture was then refluxed for 8 h and progress of reaction was monitored by thin layer chromatography. The reaction mixture was cooled and poured into crushed ice. The solid product was separated, filtered, dried and recrystallized from the methanol solvent.To a solution of 4-bromophenylhydrazine hydrochloride (2.00 g, 8.95 mmol) inηOAc (13 ml) was added cyclohexanone (0.93 ml, 8.95 mmol). The resulting mixture was heated to reflux for 7 h and then cone, in vacuo. The crude product was dissolved in EtOAc (50 ml), washed with HStep 2. 6-Bromo-2, 3, 4, 9-tetrahydro-1H-carbazole; A 250-mL round-bottomed flask was charged with 1-(4-bromophenyl)-2-cyclohexylidenehydrazine (11 g, 41.35 mmol, 1.00 equiv) and conc. HCl (150 mL). The resulting mixture was heated to 60° C. in an oil bath for 4 hours. The reaction progress was monitored by TLC (EtOAc:PE=1:1). Upon completion, the reaction mixture was cooled down to room temperature. The pH was adjusted to 8 with aqueous sodium hydroxide. The resulting mixture was then extracted with ethyl acetate (5.x.100 mL). The combined organic layers were dried over anhydrous sodium sulfate, filtered off and concentrated on a rotary evaporator. The residue was purified by a silica gel column chromatography eluted with ethyl acetate/petroleum ether (1/10) affording 3-bromo-6, 7, 8, 9-tetrahydro-5H-carbazole as yellow solid (10 g, 97percent).General procedure: T3P (50% in EtOAc) (0.55-0.68 mmol) was added to a mixture of hydrazine (59 mg, 0.55 mmol) and ketone/aldehyde (0.55 mmol) in a microwave vial. The reaction volume was then made up to 0.5 mL with EtOAc and the vessel was sealed under air. The mixture was heated under microwave irradiation (Biotage Initiator) at 100-150 C for 5-15 min. The solvent was evaporated under reduced pressure and the oily residue was purified by filtration through a plug of silica gel (eluent: isohexane/EtOAc, 8:2) to yield the desired indole or tetrahydrocarbazole. When the reaction was conducted on a 5 mmol scale the product (3a) was purified by precipitation from acetone/water.General procedure: A mixture of the carbonyl compound (5, 1.0 mmol), arylhydrazine (6, 1.2 mmol), and the solid acid (7, Amberlite, 1.5 g, obtained from Aldrich Chemical Co.) was refluxed in absolute ethanol (10 ml) for 8 h. The reaction was monitored by thin-layer chromatography(TLC), and upon completion the mixture was cooled to room temperature, the catalyst filtered off, and the product was washed thoroughly with ethylacetate (30 ml). The combined organics were washed with water, dried (Na2SO4), and concentrated in vacuo. The resulting residue was chromatographed on a silicagel column eluting with ethylacetate-hexane mixtures to obtain the purified indole (8). This was fully characterized by infrared, 400-MHz 1H NMR, high-resolution mass spectrometry, and melting point (solids).

Molecular Weight:250.13
XLogP3:4
Hydrogen Bond Donor Count:1
Exact Mass:249.01531
Monoisotopic Mass:249.01531
Topological Polar Surface Area:15.8
Heavy Atom Count:14
Complexity:218
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes