Sulfuric Acid → methyl 2,3-dihydro-1H-indole-5-carboxylate

HRID 2081705Notes

Reaction equation

HRID 2081705 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][C:6]([C:10]([O:12][CH3:13])=[O:11])=[CH:7][CH:8]=2)[CH:3]=[CH:2]1.S(=O)(=O)(O)O>CO.[Pd]>[NH:1]1[C:9]2[C:4](=[CH:5][C:6]([C:10]([O:12][CH3:13])=[O:11])=[CH:7][CH:8]=2)[CH2:3][CH2:2]1

Participants

5

Reactant 2

HCID 1118Sulfuric AcidHCID 2737635methyl 1H-indole-5-carboxylate

Product 1

HCID 21782110methyl 2,3-dihydro-1H-indole-5-carboxylate

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent

Procedure

Methyl indole-5-carboxylate (5 g) was dissolved in methanol (300 ml) containing concentrated sulphuric acid (12 ml) and 10% palladium on charcoal (1.0 g) added. The reaction mixture was hydrogenated in a Parr bottle at 65 p.s.i. with shaking for 48 hours. The catalyst was filtered off through Celite. The solution was made basic by addition of ammonia solution (0.880) and evaporated in vacuo. The product was extracted from water into ethyl acetate, the organic extracts dried over anhydrous magnesium sulphate, filtered and evaporated in vacuo to give methyl indoline-5-carboxylate, m.p. 70°-72° C.

Workup

  1. additionadded
  2. filtrationThe catalyst was filtered off through Celite
  3. additionThe solution was made basic by addition of ammonia solution (0.880)
  4. customevaporated in vacuo
  5. extractionThe product was extracted from water into ethyl acetate
  6. dry with materialthe organic extracts dried over anhydrous magnesium sulphate
  7. filtrationfiltered
  8. customevaporated in vacuo

Sources & evidence

ORD record
ord-ec9e389a9f984aac8c8b8fc72047a9e4
Source dataset
uspto-grants-1993_02
Patent number
US05185361

Reaction notes

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