Diethyl Malonate → Diethyl (cyclohex-2-en-1-yl)propanedioate

HRID 543515Notes

Reaction equation

HRID 543515 reaction equation
[Na].[C:2]([O:10][CH2:11][CH3:12])(=[O:9])[CH2:3][C:4]([O:6][CH2:7][CH3:8])=[O:5].Br[C@@H:14]1[CH2:19][CH2:18][CH2:17][CH2:16][C@H:15]1Br>C(O)C>[CH2:11]([O:10][C:2](=[O:9])[CH:3]([CH:19]1[CH2:18][CH2:17][CH2:16][CH:15]=[CH:14]1)[C:4]([O:6][CH2:7][CH3:8])=[O:5])[CH3:12]

Participants

5

Reactant 3

HCID 7761Diethyl MalonateHCID 98506trans-1,2-DibromocyclohexaneHCID 5360545Sodium

Product 1

HCID 237534Diethyl (cyclohex-2-en-1-yl)propanedioate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Within 2 hours, 1.1 l of ethanol was added dropwise to 69 g of finely chopped sodium in a 2-liter three-necked flask equipped with dropping funnel, reflux condenser, and agitator. The hot alcoholate solution was combined dropwise--again within 2 hours--with 196 g of diethyl malonate. After allowing the reaction mixture to cool, 296 g of trans-1,2-dibromocyclohexane was added--within 2 hours--to the reaction solution, which latter was then boiled under reflux overnight. After concentration of the reaction solution on a forced circulation evaporator, the residue was combined with ether and dilute hydrochloric acid, the organic phase then washed with saturated sodium chloride solution, concentrated, and distilled under vacuum, thus obtaining 197 g, bp1 119°-121° C.

Workup

  1. customequipped
  2. temperaturereflux condenser
  3. waitagain within 2 hours
  4. temperatureto cool
  5. waitwithin 2 hours
  6. temperatureunder reflux overnight
  7. customAfter concentration of the reaction solution on a forced circulation evaporator
  8. washthe organic phase then washed with saturated sodium chloride solution
  9. concentrationconcentrated
  10. distillationdistilled under vacuum
  11. customthus obtaining 197 g, bp1 119°-121° C.

Sources & evidence

ORD record
ord-a682492fda634979a40afe43e5bbc098
Source dataset
uspto-grants-1984_05
Patent number
US04446147

Reaction notes

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