Acetic Acid → 3-Ethoxy-4-phenyl-4H-furo[3,2-b]indole-2-carboxylic acid

HRID 2164340Notes

Reaction equation

HRID 2164340 reaction equation
C[O:2][C:3]([C:5]1[O:16][C:15]2[C:14]3[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=3[N:8]([C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=3)[C:7]=2[C:6]=1[O:23][CH2:24][CH3:25])=[O:4].[OH-].[Na+].C(O)(=O)C.O>CO>[CH2:24]([O:23][C:6]1[C:7]2[N:8]([C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=3)[C:9]3[CH:10]=[CH:11][CH:12]=[CH:13][C:14]=3[C:15]=2[O:16][C:5]=1[C:3]([OH:4])=[O:2])[CH3:25]

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 962WaterHCID 14798Sodium HydroxideHCID 13220390HCID 13220390, compound

Product 1

HCID 132203953-Ethoxy-4-phenyl-4H-furo[3,2-b]indole-2-carboxylic acidYield 59%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A suspension of 12.0 g (0.036 mole) of 3-ethoxy-4-phenyl-4H-furo[3,2-b]indole-2-carboxylic acid methyl ester in 100 ml of methanol was treated with 60 ml of 1.0N aqueous sodium hydroxide. After stirring at reflux for 20 hours, the cooled reaction mixture was added to 1.2 kg ice/water, and the mixture was acidified with acetic acid. The crude product was filtered, stirred in 600 ml water, and refiltered. Recrystallization from ethanol yielded 5.1 g of analytically pure acid containing 0.35 mole of water of hydration, mp 146°-147° C. An additional 1.8 g of product was obtained from the recrystallization filtrate, for a total yield of 6.9 g (59% yield).

Workup

  1. temperatureat reflux for 20 hours
  2. customthe cooled reaction mixture
  3. filtrationThe crude product was filtered
  4. stirringstirred in 600 ml water
  5. customRecrystallization from ethanol
  6. customyielded 5.1 g of analytically pure acid

Sources & evidence

ORD record
ord-c34175eba3dc4fd8ab73ac55f8fdd8cd
Source dataset
uspto-grants-1985_03
Patent number
US04503236

Reaction notes

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