Water → Ethyl 7-bromo-1H-indole-2-carboxylate

HRID 2360489

Reaction equation

HRID 2360489 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[NH:8]N.O.C1(C)C=CC(S(O)(=O)=O)=CC=1.[C:22]([O:27][CH2:28][CH3:29])(=[O:26])[C:23]([CH3:25])=O.O>C1(C)C=CC=CC=1.C(OCC)(=O)C>[Br:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]2[C:3]=1[NH:8][C:23]([C:22]([O:27][CH2:28][CH3:29])=[O:26])=[CH:25]2

Participants

7

Reactant 4

HCID 962Water3×HCID 12041Ethyl pyruvateHCID 85583(2-Bromophenyl)hydrazineHCID 521998p-Toluenesulfonic acid monohydrate2×

Product 1

HCID 7017885Ethyl 7-bromo-1H-indole-2-carboxylate

Reagents, catalysts & solvents 2

HCID 1140TolueneSolvent2×HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
40 °C

Procedure

11.0 g 2-bromophenylhydrazine and 550 mg p-toluenesulphonic acid monohydrate are dissolved in 200 ml of toluene, combined with 6.74 ml ethyl pyruvate and refluxed for 2 hours using the water separator. The mixture is allowed to cool to 40° C. and combined with a solution that is obtained by dissolving 44.75 g p-toluenesulphonic acid monohydrate in 300 ml of toluene and refluxing for two hours using the water separator. Then the mixture is refluxed for 12 hours using the water separator. After cooling to ambient temperature the solvents are eliminated in vacuo, the residue is taken up in ethyl acetate and washed successively with water and saturated aqueous sodium hydrogen carbonate solution. After drying with magnesium sulphate the mixture is combined with activated charcoal, stirred for 15 minutes and filtered through kieselguhr. The process of adding activated charcoal, stirring and filtering is repeated twice more. The solvents are eliminated in vacuo and the residue is taken up in petroleum ether/dichloromethane 7:3. 30 g of silica gel are added, the mixture is stirred for 10 minutes and then suction filtered through kieselguhr. The suction filtered silica gel is washed with petroleum ether/dichloromethane 7:3. The solvents are eliminated in vacuo.

Workup

  1. temperaturerefluxed for 2 hours
  2. customis obtained
  3. temperaturerefluxing for two hours
  4. temperatureThen the mixture is refluxed for 12 hours
  5. temperatureAfter cooling to ambient temperature the solvents
  6. washwashed successively with water and saturated aqueous sodium hydrogen carbonate solution
  7. dry with materialAfter drying with magnesium sulphate the mixture
  8. filtrationfiltered through kieselguhr
  9. additionThe process of adding activated charcoal
  10. stirringstirring
  11. filtrationfiltering
  12. addition30 g of silica gel are added
  13. stirringthe mixture is stirred for 10 minutes
  14. filtrationsuction filtered through kieselguhr
  15. filtrationThe suction filtered silica gel
  16. washis washed with petroleum ether/dichloromethane 7:3

Sources & evidence

ORD record
ord-06ccfba4493d41d8970d228e872606e7
Source dataset
uspto-grants-2014_04
Patent number
US08686022B2

Linked notes

Loading…