3-Acetoxy-2-hydroxy-4-methyl-piperidine-1-carboxylic acid → HCID 69656130, compound

HRID 7214Notes

Reaction equation

HRID 7214 reaction equation
[CH3:1][O:2][C:3]([N:5]1[CH2:10][CH2:9][CH:8]([CH3:11])[CH:7]([O:12][C:13](=[O:15])[CH3:14])[CH:6]1OC(=O)C)=[O:4].C(OC1C(C)CCN(C(O)=O)C1O)(=O)C>C(OC(=O)C)(=O)C>[CH3:1][O:2][C:3]([N:5]1[CH:6]=[C:7]([O:12][C:13](=[O:15])[CH3:14])[CH:8]([CH3:11])[CH2:9][CH2:10]1)=[O:4]

Participants

4

Reactant 2

HCID 220202363-Acetoxy-2-hydroxy-4-methyl-piperidine-1-carboxylic acidHCID 69655946HCID 69655946, compound

Product 1

HCID 69656130HCID 69656130, compound

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Conditions

Temperature
141 °C

Procedure

101.9 g (0.649 mol) of the mixture of 2,3-diacetoxy-4-methyl-piperidine-1-carboxylic acid methyl ester and 3-acetoxy-2-hydroxy-4-methyl-piperidine-1-carboxylic acid, was concentrated under reduced pressure until a solid formed. The solid was then added to a 2 L round bottom flask equipped with a nitrogen outlet, condenser and thermocouple. To this mixture was added acetic anhydride (430 ml) and then refluxed at 141° C. for two hours. The solution was stirred overnight at room temperature. Most of the acetic anhydride was removed under reduced pressure and the remaining amount was removed by adding H2O (400 ml) and a 5% solution of NaHCO3 until the pH>7. The aqueous mixture was extracted with ethyl acetate (3×250 ml), the organic layers were combined and the ethyl acetate was removed under reduced pressure. Approximately 119.0 g of a thick brown oil material 5-acetoxy-4-methyl-3,4-dihydro-2H-pyridine-1-carboxylic acid methyl ester was recovered. The TLC indicates conversion to product 5-acetoxy-4-methyl-3,4-dihydro-2H-pyridine-1-carboxylic acid methyl ester as the major component. The material was split evenly into two portions for separate hydrolysis reactions.

Workup

  1. customformed
  2. additionThe solid was then added to a 2 L round bottom flask
  3. customequipped with a nitrogen outlet, condenser
  4. customMost of the acetic anhydride was removed under reduced pressure
  5. customthe remaining amount was removed
  6. additionby adding H2O (400 ml)
  7. extractionThe aqueous mixture was extracted with ethyl acetate (3×250 ml)
  8. customthe ethyl acetate was removed under reduced pressure
  9. customApproximately 119.0 g of a thick brown oil material 5-acetoxy-4-methyl-3,4-dihydro-2H-pyridine-1-carboxylic acid methyl ester was recovered
  10. customThe material was split evenly into two portions
  11. customfor separate
  12. customhydrolysis reactions

Sources & evidence

ORD record
ord-a2e4fd09f9334ec984f9a0a948cbd985
Source dataset
uspto-grants-2006_08
Patent number
US07084277B2

Reaction notes

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