Dimethylformamide → 2-chloro-1H-indole-3-carbaldehyde

HRID 1957187Notes

Reaction equation

HRID 1957187 reaction equation
O=P(Cl)(Cl)[Cl:3].C[N:7]([CH:9]=O)[CH3:8].N1[C:12](=[O:20])[CH:13]=[C:14]2C=1[CH:18]=[CH:17][CH:16]=[CH:15]2.C([O-])(O)=O.[Na+]>ClCCl.N1C=CC=CC=1>[Cl:3][C:9]1[NH:7][C:8]2[C:14]([C:13]=1[CH:12]=[O:20])=[CH:15][CH:16]=[CH:17][CH:18]=2

Participants

7

Reactant 4

HCID 6228DimethylformamideHCID 24813Phosphorus oxychlorideHCID 516892Sodium BicarbonateHCID 17904787Indol-2-one

Product 1

HCID 3147912-chloro-1H-indole-3-carbaldehyde

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 6344DichloromethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

POCl3 (100 ml) was added dropwise to a mixture of dry DMF (100 ml) and dichloromethane (100 ml) kept at 0° C. Indolone (50 g) dissolved in dichloromethane (200 ml) and pyridine (50 ml) was added dropwise at 0° C. over a period of 1.5 h. Subsequent stirring at 0° C. for 1 h. The mixture was poured onto icewater (2000 ml) neutralised with NaHCO3 whereafter the mixture was stirred overnight. The aqueous phase was decanted and the organic phase evaporated followed by extraction with ethanol (boiling). The ethanolic phase was evaporated and the crystalline residue recrystallized from ethanol yielding 70 g of (1), m.p. 227° C.

Workup

  1. customkept at 0° C
  2. additionThe mixture was poured onto icewater (2000 ml)
  3. stirringwas stirred overnight
  4. customThe aqueous phase was decanted
  5. customthe organic phase evaporated
  6. extractionfollowed by extraction with ethanol (boiling)
  7. customThe ethanolic phase was evaporated
  8. customthe crystalline residue recrystallized from ethanol yielding 70 g of (1), m.p. 227° C.

Sources & evidence

ORD record
ord-b4d54b5a85634b459a3b0e33c272ac6d
Source dataset
uspto-grants-1998_07
Patent number
US05783575

Reaction notes

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