Hydrochloric Acid → Ethyl 6-(1-benzyloxycarbonyl-4-piperidyl)-2-oxohexanoate

HRID 1031822Notes

Reaction equation

HRID 1031822 reaction equation
C(Cl)(=O)C(Cl)=O.[CH2:7]([O:14][C:15]([N:17]1[CH2:22][CH2:21][CH:20]([CH2:23][CH2:24][CH2:25][CH2:26][CH:27]([OH:33])[C:28]([O:30][CH2:31][CH3:32])=[O:29])[CH2:19][CH2:18]1)=[O:16])[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1.C(N(CC)C(C)C)C.Cl>C(Cl)Cl.CS(C)=O>[CH2:7]([O:14][C:15]([N:17]1[CH2:22][CH2:21][CH:20]([CH2:23][CH2:24][CH2:25][CH2:26][C:27](=[O:33])[C:28]([O:30][CH2:31][CH3:32])=[O:29])[CH2:19][CH2:18]1)=[O:16])[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 65578Oxalyl chlorideHCID 521913N,N-Diethyl-2-propanamineHCID 13817553Ethyl 6-(1-benzyloxycarbonyl-4-piperidyl)-2-hydroxyhexanoate

Product 1

HCID 13817563Ethyl 6-(1-benzyloxycarbonyl-4-piperidyl)-2-oxohexanoateYield 52.3%

Reagents, catalysts & solvents 2

HCID 679Dimethyl SulfoxideSolventHCID 6344DichloromethaneSolvent3×

Conditions

Temperature
-60 °C

Procedure

To a solution of 2.3 ml of oxalyl chloride in 40 ml of methylene chloride cooled at -65° C. is added a solution of 4.45 g of dimethylsulfoxide in 20 ml of methylene chloride over a period of 10 minutes, and the mixture is stirred at -60° C. for 10 minutes. To the mixture is added a solution of 5 g of ethyl 6-(1-benzyloxycarbonyl-4-piperidyl)-2-hydroxyhexanoate in 50 ml of methylene chloride over a period of 10 minutes, and the resulting mixture is stirred at -60° C. for 20 minutes. To the mixture is added 10.3 g of diethylisopropylamine over a period of 10 minutes, and the temperature is raised from -60° C. up to -30° C. To the mixture is added 80 ml of 1N hydrochloric acid, and the mixture is stirred at room temperature. The methylene chloride layer is separated, washed with water, dried and concentrated under reduced pressure. The residue is purified by silicagel column chromatography (hexane:ethyl acetate=4:1 to 2:1), to give 2.6 g of ethyl 6-(1-benzyloxycarbonyl-4-piperidyl)-2-oxohexanoate as an oil.

Workup

  1. stirringthe resulting mixture is stirred at -60° C. for 20 minutes
  2. temperaturethe temperature is raised from -60° C. up to -30° C
  3. stirringthe mixture is stirred at room temperature
  4. customThe methylene chloride layer is separated
  5. washwashed with water
  6. customdried
  7. concentrationconcentrated under reduced pressure
  8. customThe residue is purified by silicagel column chromatography (hexane:ethyl acetate=4:1 to 2:1)

Sources & evidence

ORD record
ord-5b67134163044721aa55c30da67abf46
Source dataset
uspto-grants-1990_09
Patent number
US04954625

Reaction notes

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