Water → 1-(6-Acetyl-9H-carbazol-3-yl)-ethanone
Reaction equation
[CH:1]1[C:13]2[NH:12][C:11]3[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=3)[C:5]=2[CH:4]=[CH:3][CH:2]=1.[Al+3].[Cl-].[Cl-].[Cl-].[C:18](Cl)([CH3:20])=[O:19].[OH2:22].[N+]([C:26]1[CH:31]=CC=CC=1)([O-])=O>>[C:18]([C:3]1[CH:2]=[CH:1][C:13]2[NH:12][C:11]3[C:6]([C:5]=2[CH:4]=1)=[CH:7][C:8]([C:31](=[O:22])[CH3:26])=[CH:9][CH:10]=3)(=[O:19])[CH3:20]Participants
Procedure
Carbazole 1 (16.9 g, 0.1 mol) was dissolved in nitrobenzene (300 mL). Anhydrous AlCl3 (54.0 g, 0.4 mol) was added under stirring and cooling with an ice bath. Then, AcCl (55.5 g, 0.7 mol) was added slowly dropwise. The reaction mixture was allowed to warm to room temperature under stirring and kept over a period of 13 h. Water (500 mL) was added in small portions under cooling with an ice bath. The cooling bath was removed, and the mixture was refluxed over a period of 2 h and extracted with CHCl3 (3×150 mL). The combined extracts were sequentially washed with saturated solutions of NaHCO3 and NaCl, dried with anhydrous Na2SO4, and evaporated. The residue was purified by column chromatography (silica gel, CHCl3/MeOH) to give 12.5 g (50%) of 3,6-diacetylcarbazole (4).
Workup
- temperaturecooling with an ice bath
- stirringunder stirring
- temperatureunder cooling with an ice bath
- customThe cooling bath was removed
- temperaturethe mixture was refluxed over a period of 2 h
- extractionextracted with CHCl3 (3×150 mL)
- washThe combined extracts were sequentially washed with saturated solutions of NaHCO3 and NaCl
- dry with materialdried with anhydrous Na2SO4
- customevaporated
- customThe residue was purified by column chromatography (silica gel, CHCl3/MeOH)
Sources & evidence
- ORD record
- ord-36e195d518564bff840e238740612fc4
- Source dataset
- uspto-grants-2014_07
- Patent number
- US08765738B2
Reaction notes
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