Oxalic Acid → 1,10-Dimethyl-3,4-dihydro-1H-1,4-oxazino[4,3-a]indole-1-propionaldehyde

HRID 1657752Notes

Reaction equation

HRID 1657752 reaction equation
[CH3:1][C:2]1([CH2:16][CH2:17][CH2:18][OH:19])[C:7]2=[C:8]([CH3:15])[C:9]3[CH:10]=[CH:11][CH:12]=[CH:13][C:14]=3[N:6]2[CH2:5][CH2:4][O:3]1.FC(F)(F)C(O)=O.N1C=CC=CC=1.C(O)(=O)C(O)=O>O.CO.CCOCC>[CH3:1][C:2]1([CH2:16][CH2:17][CH:18]=[O:19])[C:7]2=[C:8]([CH3:15])[C:9]3[CH:10]=[CH:11][CH:12]=[CH:13][C:14]=3[N:6]2[CH2:5][CH2:4][O:3]1

Participants

8

Reactant 4

HCID 971Oxalic AcidHCID 1049PyridineHCID 6422Trifluoroacetic acidHCID 213895531,10-Dimethyl-3,4-dihydro-1H-1,4-oxazino[4,3-a]indole-1-propanol

Product 1

HCID 213895661,10-Dimethyl-3,4-dihydro-1H-1,4-oxazino[4,3-a]indole-1-propionaldehyde

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolventHCID 3283Diethyl EtherSolvent

Procedure

N,N-Dicyclohexylcarbodiimide (2.87 g.) is added to a cooled, stirred solution of the primary alcohol, 1,10-dimethyl-3,4-dihydro-1H-1,4-oxazino[4,3-a]indole-1-propanol (1.0 g.), described in Example 462, in 10 ml. of dimethyl sulfoxidebenzene (2:1) containing trifluoroacetic acid (0.18 ml.) and pyridine (0.38 ml.). The reaction is stirred at room temperature under nitrogen for 5 hr. The reaction mixture is now diluted with 100 ml. of ether, followed by the dropwise addition of a solution of oxalic acid (1.26 g.) in 6 ml. of methanol. After thirty minutes, water (100 ml.) is added and the insoluble material is collected. The organic phase is washed with water (2X), 5% aqueous sodium bicarbonate (2X) and water (2X). After drying (MgSO4) the organic phase is evaporated to yield an oil. The oil is purified by chromatography on silica gel. Elution with 10% ether in benzene affords the title compound as an oil, δCHCl3Max 1720 cm-1.

Workup

  1. additionThe reaction mixture is now diluted with 100 ml
  2. waitAfter thirty minutes
  3. customthe insoluble material is collected
  4. washThe organic phase is washed with water (2X), 5% aqueous sodium bicarbonate (2X) and water (2X)
  5. dry with materialAfter drying (MgSO4) the organic phase
  6. customis evaporated
  7. customto yield an oil
  8. customThe oil is purified by chromatography on silica gel
  9. washElution with 10% ether in benzene

Sources & evidence

ORD record
ord-f08501c0861640989f2436350b746b07
Source dataset
uspto-grants-1976_06
Patent number
US03962236

Reaction notes

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