Phosphorus oxychloride → 3-formyl-N-pentenyl-carbazole
Reaction equation
P(Cl)(Cl)(Cl)=O.[CH:6]([N:11]1[C:23]2[CH:22]=[CH:21][CH:20]=[CH:19][C:18]=2[C:17]2[C:12]1=[CH:13][CH:14]=[CH:15][CH:16]=2)=[CH:7][CH2:8][CH2:9][CH3:10].[C:24]([O-])(=[O:26])C.[Na+]>CN(C)C=O>[CH:24]([C:20]1[CH:21]=[CH:22][C:23]2[N:11]([CH:6]=[CH:7][CH2:8][CH2:9][CH3:10])[C:12]3[C:17]([C:18]=2[CH:19]=1)=[CH:16][CH:15]=[CH:14][CH:13]=3)=[O:26]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 100 °C
Procedure
Phosphorus oxychloride (9.1 g, 60mmol) was added to dimethylformamide (17 mL) at 0° C. with strong stirring over 15 minutes. Upon complete addition, the orange solution was stirred at 0° C. for a further 10 minutes. N-pentenyl-carbazole (10.5 g, 45 mmol) was gradually added to the iminium salt and the mixture was heated at 100° C. for 1.5 hours, then cooled to room temperature and added to ice. The ice slurry was adjusted to a pH of 6 with saturated sodium acetate solution and the crude product was extracted with dichloromethane (2×50 mL), dried (Na2SO4), and concentrated. Traces of dimethylformamide were removed under high vacuum to give 9.6 g of 3-formyl-N-pentenyl-carbazole as a brown oil. The material was used at this level of purity in the next step of the synthesis.
Workup
- additionUpon complete addition
- stirringthe orange solution was stirred at 0° C. for a further 10 minutes
- temperaturecooled to room temperature
- additionadded to ice
- extractionthe crude product was extracted with dichloromethane (2×50 mL)
- dry with materialdried (Na2SO4)
- concentrationconcentrated
- customTraces of dimethylformamide were removed under high vacuum
Sources & evidence
- ORD record
- ord-983b81a2e9444664923a9bef92564987
- Source dataset
- uspto-grants-2000_10
- Patent number
- US06140004
Reaction notes
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