Catechol → 1'-ethoxycarbonyl-spiro[1,3-benzodioxole-2,4'-piperidine]

HRID 378555Notes

Reaction equation

HRID 378555 reaction equation
[CH2:1]([O:3][C:4]([N:6]1[CH2:11][CH2:10][C:9](=[O:12])[CH2:8][CH2:7]1)=[O:5])[CH3:2].[C:13]1([C:15](=[CH:17][CH:18]=[CH:19][CH:20]=1)O)[OH:14].C1(C)C=CC(S(O)(=O)=O)=CC=1.O>C1(C)C=CC=CC=1>[CH2:1]([O:3][C:4]([N:6]1[CH2:7][CH2:8][C:9]2([O:14][C:13]3[CH:15]=[CH:17][CH:18]=[CH:19][C:20]=3[O:12]2)[CH2:10][CH2:11]1)=[O:5])[CH3:2]

Participants

6

Reactant 4

HCID 289CatecholHCID 962WaterHCID 6101p-Toluenesulfonic acidHCID 34767Ethyl 4-oxo-1-piperidinecarboxylate

Product 1

HCID 104454571'-ethoxycarbonyl-spiro[1,3-benzodioxole-2,4'-piperidine]

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of 1-ethoxycarbonyl-4-piperidinone (17 g), pyrocatechol (13 g) and p-toluenesulfonic acid (2.5 g) in 250 ml of dry toluene was refluxed with continous removal of water. After 3 h the reaction mixture was concentrated in vacuo, 2% NaOH (200 ml) was added followed by extraction with dichloromethane. After drying over magnesium sulfate and removal of solvent in vacuo, the remaining red oil was applied to a silica gel column (eluent: ethyl acetate/heptane=1:1) giving 22 g of a slightly yellow oil, 1'-ethoxycarbonyl-spiro[1,3-benzodioxole-2,4'-piperidine].

Workup

  1. concentrationAfter 3 h the reaction mixture was concentrated in vacuo, 2% NaOH (200 ml)
  2. additionwas added
  3. extractionfollowed by extraction with dichloromethane
  4. dry with materialAfter drying over magnesium sulfate and removal of solvent in vacuo

Sources & evidence

ORD record
ord-dee80ce5b2e94acd9437610e101a20a8
Source dataset
uspto-grants-2000_02
Patent number
US06031099

Reaction notes

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