Sulfuric Acid → Tert-butyl octahydro-1H-indole-2-carboxylate

HRID 917797Notes

Reaction equation

HRID 917797 reaction equation
[NH:1]1[CH:9]2[CH:4]([CH2:5][CH2:6][CH2:7][CH2:8]2)[CH2:3][CH:2]1[C:10]([OH:12])=[O:11].OS(O)(=O)=O>C(Cl)(Cl)Cl>[C:4]([O:11][C:10]([CH:2]1[CH2:3][CH:4]2[CH:9]([CH2:8][CH2:7][CH2:6][CH2:5]2)[NH:1]1)=[O:12])([CH3:9])([CH3:5])[CH3:3]

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 3274680Octahydroindole-2-carboxylic acid

Product 1

HCID 13308983Tert-butyl octahydro-1H-indole-2-carboxylateYield 200%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

Octahydro-indole-2-carboxylic acid 11b (5.0 g, 29.5 mmol, purchased from Bachem) was suspended in 200 mL of CHCl3 then cooled in a dry ice/acetone bath. H2SO4 (120 uL/mmol) was added followed by bubbling in excess isobutylene. The mixture was sealed and the ice bath removed. The mixture was stirred at RT for 12 hours. The reaction mixture was carefully unsealed after cooling and concentrated. EtOAc was added and washed with saturated sodium bicarbonate soln, brine, dried over sodium sulfate, then filtered and concentrated to give octahydro-indole-2-carboxylic acid tert-butyl ester 12b (6.65 g, 29.5 mmol, 100%).

Workup

  1. temperaturethen cooled in a dry ice/acetone bath
  2. customby bubbling in excess isobutylene
  3. customThe mixture was sealed
  4. customthe ice bath removed
  5. temperatureafter cooling
  6. concentrationconcentrated
  7. additionEtOAc was added
  8. washwashed with saturated sodium bicarbonate soln
  9. dry with materialbrine, dried over sodium sulfate
  10. filtrationfiltered
  11. concentrationconcentrated

Sources & evidence

ORD record
ord-478737160a0b4107b08f5ffedda8b0ce
Source dataset
uspto-grants-2007_09
Patent number
US07273885B2

Reaction notes

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