Trimethyl orthoformate → 3-Oxo-cyclopentanecarboxylic acid methyl ester

HRID 1488720Notes

Reaction equation

HRID 1488720 reaction equation
[O:1]=[C:2]1[CH2:6][CH2:5][CH:4]([C:7]([OH:9])=[O:8])[CH2:3]1.O.[C:11]1(C)C(S(O)(=O)=O)=CC=CC=1.C(OC)(OC)OC>CO>[O:1]=[C:2]1[CH2:6][CH2:5][CH:4]([C:7]([O:9][CH3:11])=[O:8])[CH2:3]1

Participants

5

Reactant 3

HCID 9005Trimethyl orthoformateHCID 2277983-Oxocyclopentanecarboxylic acidHCID 124969952-Methylbenzenesulfonic acid hydrate

Product 1

HCID 2376403-Oxo-cyclopentanecarboxylic acid methyl ester

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of 193.8 g (1.51 moles) of 3-oxocyclopentane carboxylic acid in 580 ml of methanol, analytical grade, is treated with 1.8 g (9.5 mmoles) of toluene sulphonic acid hydrate with stirring, then 192.4 g (1.81 moles) of trimethyl orthoformate are added in the course of 10 minutes and the mixture is heated to boiling under reflux. This temperature is maintained for 1 hour. The solution is evaporated in vacuo (i.v.), the residue is treated with 200 ml of H2O, 220 ml of toluene and 1.9 ml of concentrated H2SO4 and stirred at room temperature for 1 hour. The phases are separated, the aqueous phase is extracted 3× using 50 ml of toluene each time, the combined organic phases are washed 1× using 90 ml of 2.5% strength LiOH solution and 2× using 50 ml of H2O each time. The organic phase is dried using magnesium sulphate and evaporated in vacuo. The oily residue is fractionally distilled using a water-jet vacuum.

Workup

  1. temperaturethe mixture is heated
  2. temperatureunder reflux
  3. temperatureThis temperature is maintained for 1 hour
  4. customThe solution is evaporated in vacuo (i.v.)
  5. additionthe residue is treated with 200 ml of H2O, 220 ml of toluene and 1.9 ml of concentrated H2SO4
  6. stirringstirred at room temperature for 1 hour
  7. customThe phases are separated
  8. extractionthe aqueous phase is extracted 3×
  9. washthe combined organic phases are washed 1×
  10. customThe organic phase is dried
  11. customevaporated in vacuo
  12. distillationThe oily residue is fractionally distilled

Sources & evidence

ORD record
ord-73fd1359488c4f5ab032a7b88d5391cf
Source dataset
uspto-grants-1997_10
Patent number
US05675005

Reaction notes

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