1,3-Cyclohexadiene → HCID 20035402, compound

HRID 1905354Notes

Reaction equation

HRID 1905354 reaction equation
[CH:1]([CH:4]1[CH:9]([C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH:8]([CH3:15])[CH:7]=[CH:6][CH2:5]1)([CH3:3])[CH3:2].BrN1C(=O)CCC1=O.C1CC=CC=C1>C(Cl)(Cl)(Cl)Cl>[CH:1]([CH:4]1[C:9]([C:10]([O:12][CH2:13][CH3:14])=[O:11])=[C:8]([CH3:15])[CH:7]=[CH:6][CH2:5]1)([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 116051,3-CyclohexadieneHCID 67184N-bromobutanimideHCID 20035406HCID 20035406, compound

Product 1

HCID 20035402HCID 20035402, compound

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Conditions

Temperature
120 °C

Procedure

A mixture of 10.5 g (0.05 mol) of ethyl 6-isopropyl-2-methyl-3-cyclohexene-1-carboxylate (mixture of isomers obtained according to Example 1) and 9.8 g (0.055 mol) of N-bromosuccinimide dissolved in 75 ml of CCl4 was stirred for 3 hours under reflux. After cooling the reaction mixture was filtered and the filter cake was washed with some cold CCl4. The filtrate was evaporated down and the evaporation residue dissolved in 50 ml of dimethylformamide. 1.2 g of LiF and 3.4 g of Li2CO3 were added to this solution and the mixture was heated at 120° C. with continuous stirring for 1 hour. After cooling, 150 ml of water were added and the mixture was extracted 3 times with 50 ml of petroleum ether 40`-60. The extract was washed with water, dried and evaporated down, after which the residue was distilled. 8.1 g were obtained of a mixture, 60% of which consisted of the 2,4-cyclohexadiene isomer and the rest of the 1,3- and 2(exocyclic), 3-isomers of said compound. b.p.: 85°-88° C./0.6 kPa; NMR (data of the 2,4-isomer): 0.87 (3H, d, J=7 Hz); 0.90 (3H, d, J=7 Hz); 1.24 (3H, t, J=7 Hz); 1.6 (1H, m); 1.77 (3H, broad s); 2.54 (1H, m); 2.86 (1H, d, J=7 Hz); 4.07 (2H, k, J=7 Hz); 5.3-5.9 (3H).

Workup

  1. temperatureunder reflux
  2. temperatureAfter cooling the reaction mixture
  3. filtrationwas filtered
  4. washthe filter cake was washed with some cold CCl4
  5. customThe filtrate was evaporated down
  6. dissolutionthe evaporation residue dissolved in 50 ml of dimethylformamide
  7. addition1.2 g of LiF and 3.4 g of Li2CO3 were added to this solution
  8. stirringwith continuous stirring for 1 hour
  9. temperatureAfter cooling
  10. addition150 ml of water were added
  11. extractionthe mixture was extracted 3 times with 50 ml of petroleum ether 40`-60
  12. washThe extract was washed with water
  13. customdried
  14. customevaporated down
  15. distillationafter which the residue was distilled
  16. custom8.1 g were obtained of a mixture, 60% of which

Sources & evidence

ORD record
ord-0c028941de624df3868e1d969db111f0
Source dataset
uspto-grants-1989_06
Patent number
US04843061

Reaction notes

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