Phosphorus oxychloride → ethyl 5-chloro-3-formyl-1H-indole-2-carboxylate

HRID 2104397Notes

Reaction equation

HRID 2104397 reaction equation
P(Cl)(Cl)(Cl)=O.CN([CH:14]=[O:15])C1C=CC=CC=1.[CH2:16]([O:18][C:19]([C:21]1[NH:22][C:23]2[C:28]([CH:29]=1)=[CH:27][C:26]([Cl:30])=[CH:25][CH:24]=2)=[O:20])[CH3:17].C([O-])(=O)C.[Na+]>ClCCCl>[CH2:16]([O:18][C:19]([C:21]1[NH:22][C:23]2[C:28]([C:29]=1[CH:14]=[O:15])=[CH:27][C:26]([Cl:30])=[CH:25][CH:24]=2)=[O:20])[CH3:17]

Participants

6

Reactant 4

HCID 24813Phosphorus oxychlorideHCID 66737N-MethylformanilideHCID 78518Ethyl 5-chloroindole-2-carboxylateHCID 517045Sodium Acetate

Product 1

HCID 4410568ethyl 5-chloro-3-formyl-1H-indole-2-carboxylateYield 79.1%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Procedure

Phosphorus oxychloride (2.0 mL) was added to N-methylformanilide (2.9 g), and after the mixture was stirred for 15 minutes, 1,2-dichloroethane (50 mL) and 5-chloroindole-2-carboxylic acid ethyl ester (4.0 g) were added thereto, followed by heating under reflux for 1 hour. The reaction mixture was poured into an aqueous solution (28 mL) of sodium acetate (14 g) under ice cooling, and the thus-obtained mixture was stirred for 18 hours. Insoluble matter was collected by filtration, and was sequentially washed with water and diethyl ether, to thereby give the title compound (3.56 g).

Workup

  1. temperatureby heating
  2. temperatureunder reflux for 1 hour
  3. stirringthe thus-obtained mixture was stirred for 18 hours
  4. filtrationInsoluble matter was collected by filtration
  5. washwas sequentially washed with water and diethyl ether

Sources & evidence

ORD record
ord-1ab6c9c7a64a4bd69c583c9c181a6c61
Source dataset
uspto-grants-2009_08
Patent number
US07576135B2

Reaction notes

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