Acetic Acid → Ethyl 4-(benzyloxy)-6-methyl-1H-indole-2-carboxylate

HRID 903918Notes

Reaction equation

HRID 903918 reaction equation
[CH2:1]([O:3][C:4](=[O:26])[C:5]([CH2:7][C:8]1[C:13]([N+:14]([O-])=O)=[CH:12][C:11]([CH3:17])=[CH:10][C:9]=1[O:18][CH2:19][C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)=O)[CH3:2].C(O)(=O)C>O>[CH2:19]([O:18][C:9]1[CH:10]=[C:11]([CH3:17])[CH:12]=[C:13]2[C:8]=1[CH:7]=[C:5]([C:4]([O:3][CH2:1][CH3:2])=[O:26])[NH:14]2)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1

Participants

4

Reactant 2

HCID 176Acetic AcidHCID 543832372-Benzyloxy-4-methyl-6-nitrophenyl pyruvic acid ethyl ester

Product 1

HCID 23335518Ethyl 4-(benzyloxy)-6-methyl-1H-indole-2-carboxylateYield 59%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

The solution of 30.6 g of the thus prepared 2-benzyloxy-4-methyl-6-nitrophenyl pyruvic acid ethyl ester in a composition of 250 ml glacial acetic acid and 15 ml water is brought to boiling. The heating is removed and the solution is mixed with 33.6 g zinc dust in such a manner that the boiling temperature is maintained. 5.6 g zinc dust is additionally added and heated to boiling for 30 minutes. The mixture is aspirated from the excessive zinc dust while still hot. The filter cake is washed well with glacial acetic acid and ethanol. The precipitate resulting during the cooling of the filtrate is aspirated and dried. There is obtained 15.7 g (~59% of theory) 4-benzyloxy-2-ethoxycarbonyl-6-methylindole; m.p. 167°-168° C.

Workup

  1. customThe heating is removed
  2. additionthe solution is mixed with 33.6 g zinc dust in such a manner that the boiling temperature
  3. temperatureis maintained
  4. addition5.6 g zinc dust is additionally added
  5. temperatureheated
  6. washThe filter cake is washed well with glacial acetic acid and ethanol
  7. customThe precipitate resulting during the
  8. temperaturecooling of the filtrate
  9. customdried

Sources & evidence

ORD record
ord-450d988386ba4acc847cbd53ddeb97aa
Source dataset
uspto-grants-1980_10
Patent number
US04229464

Reaction notes

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