Phosphorus oxychloride → methyl 3-formyl-1H-indole-4-carboxylate

HRID 1605261Notes

Reaction equation

HRID 1605261 reaction equation
CN([CH:9]=[O:10])C1C=CC=CC=1.P(Cl)(Cl)(Cl)=O.[CH3:16][O:17][C:18]([C:20]1[C:21]2[CH:22]=[CH:23][NH:24][C:25]=2[CH:26]=[CH:27][CH:28]=1)=[O:19].C([O-])(=O)C.[Na+]>C(Cl)CCl>[CH3:16][O:17][C:18]([C:20]1[C:21]2[C:22]([CH:9]=[O:10])=[CH:23][NH:24][C:25]=2[CH:26]=[CH:27][CH:28]=1)=[O:19]

Participants

6

Reactant 4

HCID 24813Phosphorus oxychlorideHCID 66737N-MethylformanilideHCID 517045Sodium AcetateHCID 2733668methyl 1H-indole-4-carboxylate

Product 1

HCID 12396096methyl 3-formyl-1H-indole-4-carboxylate

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent2×

Procedure

To a stirred mixture of N-methylformanilide (15.6 g) and phosphorus oxychloride (17.7 g) is added ethylene dichloride (75 g ) followed by 4-indolecarboxylic acid methyl ester (17.5 g). The reaction mixture is stirred at room temperature for 1 1/2 hr., then at 45°-50°C for 30 minutes more. The mixture is now poured into a solution of 75 g of sodium acetate in 150 ml of ice-water. More ethylene dichloride is added. The layers are separated and the organic phase is washed with water, dried (Na2SO4) and evaporated under reduced pressure. The residual brown oil is passed through a silica gel column using 3% methanol in chloroform. Concentration of the eluate affords a solid which on recrystallization from benzene affords the pure title compound, mp 135°C.

Workup

  1. wait, then at 45°-50°C for 30 minutes more
  2. customThe layers are separated
  3. washthe organic phase is washed with water
  4. dry with materialdried (Na2SO4)
  5. customevaporated under reduced pressure
  6. customConcentration of the eluate affords a solid which
  7. customon recrystallization from benzene

Sources & evidence

ORD record
ord-b0fae94079674ec1af322f19032d2701
Source dataset
uspto-grants-1976_04
Patent number
US03950343

Reaction notes

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