Hydrochloric Acid → (3R,5S)-1-Benzyl-3,5-dimethylpiperidin-4-one

HRID 1992662Notes

Reaction equation

HRID 1992662 reaction equation
[CH2:1]([N:8]1[CH2:13][C:12](C)([C:14](OC)=O)[C:11](=[O:19])[C:10](C)([C:20](OC)=O)[CH2:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.Cl.[OH-].[Na+]>>[CH2:1]([N:8]1[CH2:13][C@H:12]([CH3:14])[C:11](=[O:19])[C@H:10]([CH3:20])[CH2:9]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 59131046HCID 59131046, compound

Product 1

HCID 59130974(3R,5S)-1-Benzyl-3,5-dimethylpiperidin-4-oneYield 95%

Conditions

Temperature
10 °C

Procedure

A mixture of the crude dimethyl 1-benzyl-3,5-dimethyl-4-oxopiperidine-3,5-dicarboxylate (786.0 g, ca. 2.3 mol) and 1M hydrochloric acid solution (11.5 L) was refluxed for 24 hours. The reaction mixture was cooled to 10° C. and 25% wt. aqueous sodium hydroxide solution (1.92 kg) was added slowly. The mixture was extracted with dichloromethane (4×4 L), and the combined organic extracts concentrated to dryness to give the crude (3R,5S)-1-benzyl-3,5-dimethylpiperidin-4-one (475 g) as a light brown oil. The 1H NMR indicated that it was a 6:1 desired: undesired diastereomeric mixture.

Workup

  1. temperaturewas refluxed for 24 hours
  2. extractionThe mixture was extracted with dichloromethane (4×4 L)
  3. concentrationthe combined organic extracts concentrated to dryness

Sources & evidence

ORD record
ord-1bed1342ed7c458e847294511355c766
Source dataset
uspto-grants-2010_01
Patent number
US07649002B2

Reaction notes

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