Carbon Dioxide → 3-(4,5,6,7-tetrahydro-1H-indol-3-yl)-propionic acid

HRID 1761142Notes

Reaction equation

HRID 1761142 reaction equation
C(OC([C:6]1[NH:7][C:8]2[CH2:9][CH2:10][CH2:11][CH2:12][C:13]=2[C:14]=1[CH2:15][CH2:16][C:17]([O:19]CC)=[O:18])=O)C.[OH-].[Na+].Cl.C(=O)=O>C(OCC)(=O)C>[C:17]([CH2:16][CH2:15][C:14]1[C:13]2[CH2:12][CH2:11][CH2:10][CH2:9][C:8]=2[NH:7][CH:6]=1)([OH:19])=[O:18]

Participants

6

Reactant 4

HCID 280Carbon DioxideHCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 108036583-(2-ethoxycarbonylethyl)-4,5,6,7-tetrahydro-1H-indole-2-carboxylic acid ethyl ester2×

Product 1

HCID 107978613-(4,5,6,7-tetrahydro-1H-indol-3-yl)-propionic acid

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

Crude 2-ethoxycarbonyl-3-(2-ethoxycarbonylethyl)-4,5,6,7-tetrahydroindole (30 g) and 80 mL of 5 N sodium hydroxide were refluxed for 80 min in a round bottom flask heated in an oil bath and equipped with magnetic stirring. The heater was turned off, but the flask was left in the hot bath, and about 44 mL of 10 N hydrochloric acid was cautiously added via a dropping funnel through the reflux condenser with vigorous stirring. When approximately 80% of the acid had been added, a large amount of carbon dioxide was evolved. The addition was continued until the pH was 2-3. The mixture was cooled in a water bath, and 200 mL of ethyl acetate was added to dissolve the oil that was present. The ethyl acetate layer was isolated and was washed 3 times with 50 mL of water each time, twice with 30 mL of brine each time, and was dried over 5 g of anhydrous sodium sulfate and was evaporated to give 15.5 g (80%) yield of crude 3-(2-carboxyethyl)-4,5,6,7-tetrahydroindole as a very dark sticky syrup.

Workup

  1. temperatureheated in an oil bath
  2. customequipped with magnetic stirring
  3. additionwas cautiously added via a dropping funnel through the reflux condenser with vigorous stirring
  4. additionThe addition
  5. temperatureThe mixture was cooled in a water bath
  6. dissolutionto dissolve the oil that
  7. washwas washed 3 times with 50 mL of water each time
  8. dry with materialtwice with 30 mL of brine each time, and was dried over 5 g of anhydrous sodium sulfate
  9. customwas evaporated

Sources & evidence

ORD record
ord-2127a62c79fa438aadb2b2a3737a7e14
Source dataset
uspto-grants-2005_01
Patent number
US06846839B1

Reaction notes

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