Oxalic Acid → HCID 20548860, compound

HRID 971693Notes

Reaction equation

HRID 971693 reaction equation
[OH:1][C@H:2]1[C@H:7]([O:8][C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)[CH2:6][CH2:5][N:4]([C:15]([O:17][CH2:18][C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)=[O:16])[CH2:3]1.C1(N=C=NC2CCCCC2)CCCCC1.N1C=CC=CC=1.FC(F)(F)C(O)=O.C(O)(=O)C(O)=O>CS(C)=O.CO.O>[O:8]([CH:7]1[CH2:6][CH2:5][N:4]([C:15]([O:17][CH2:18][C:19]2[CH:20]=[CH:21][CH:22]=[CH:23][CH:24]=2)=[O:16])[CH2:3][C:2]1=[O:1])[C:9]1[CH:10]=[CH:11][CH:12]=[CH:13][CH:14]=1

Participants

9

Reactant 5

HCID 971Oxalic AcidHCID 1049PyridineHCID 6422Trifluoroacetic acidHCID 10868DicyclohexylcarbodiimideHCID 70544672HCID 70544672, compound

Product 1

HCID 20548860HCID 20548860, compound

Reagents, catalysts & solvents 3

HCID 679Dimethyl SulfoxideSolventHCID 887MethanolSolventHCID 962WaterSolvent

Procedure

15.0 g (0.045 mol) of the trans-3-hydroxy-4-phenoxy-1-carbobenzyloxy-piperidine described in Example 14 are dissolved, together with 28.34 g (0.13 mol) of dicyclohexylcarbodiimide and 3.7 ml (0.045 mol) of pyridine, in 80 ml of dry dimethylsulphoxide. The mixture is cooled to 0° with an ice-water bath and treated with 2.6 g (0.023 mol) of trifluoroacetic acid. The cooling bath is removed again and the reaction mixture is stirred for a further 4 hours at room temperature in a nitrogen atmosphere. The white suspension is diluted with 250 ml of ethyl acetate and treated dropwise with a solution of 12.3 g (0.13 mol) of oxalic acid in 200 ml of methanol. After the evolution of gas has ceased, the reaction mixture is cooled to 0° in an ice-water bath and diluted with 400 ml of water and the dicyclohexylurea which has precipitated is separated off. The aqueous phase of the filtrate is extracted with 250 ml of ethyl acetate and the combined organic phases are dried over sodium sulphate and evaporated to dryness under a water pump vacuum. The resulting crude product is dissolved in benzene and the solution is filtered through a layer of silica gel. 4-Phenoxy-1-carbobenzyloxy-3-piperidone is obtained in the form of a pale yellow oil by elution with a benzene/ethyl acetate mixture (95:5).

Workup

  1. temperatureThe mixture is cooled to 0° with an ice-water bath
  2. customThe cooling bath is removed again
  3. additionThe white suspension is diluted with 250 ml of ethyl acetate
  4. temperaturethe reaction mixture is cooled to 0° in an ice-water bath
  5. customthe dicyclohexylurea which has precipitated
  6. customis separated off
  7. extractionThe aqueous phase of the filtrate is extracted with 250 ml of ethyl acetate
  8. dry with materialthe combined organic phases are dried over sodium sulphate
  9. customevaporated to dryness under a water pump vacuum
  10. dissolutionThe resulting crude product is dissolved in benzene
  11. filtrationthe solution is filtered through a layer of silica gel

Sources & evidence

ORD record
ord-beb204e8437b4900b7e27e641be91260
Source dataset
uspto-grants-1979_07
Patent number
US04160837

Reaction notes

Loading…