Hydrochloric Acid → HCID 10470453, compound

HRID 2057502Notes

Reaction equation

HRID 2057502 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([Br:8])=[CH:4][CH:3]=1.C([Li])CCC.[CH2:14]([CH:19]1[CH2:24][CH2:23][C:22](=O)[CH2:21][CH2:20]1)[CH2:15][CH2:16][CH2:17][CH3:18].Cl>C1(C)C=CC=CC=1.CCCCCC>[Br:8][C:5]1[CH:6]=[CH:7][C:2]([C:22]2[CH2:23][CH2:24][CH:19]([CH2:14][CH2:15][CH2:16][CH2:17][CH3:18])[CH2:20][CH:21]=2)=[CH:3][CH:4]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 78041,4-DibromobenzeneHCID 5660974-PentylcyclohexanoneHCID 178418339Butyllithium

Product 1

HCID 10470453HCID 10470453, compoundYield 65.1%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolvent2×HCID 8058HexaneSolvent

Conditions

Temperature
50 °C

Procedure

236 Grams (1 mol) of p-dibromobenzene and 1 l of dry toluene were introduced into a three-neck flask in dry nitrogen atmosphere to carry out dissolution with stirring at 50° C. To the resulting solution was dropwise added 525 ml of a hexane solution of 1.67 N commercial n-butyllithium (0.88 mol), over 30 minutes. After dropping, the temperature was maintained at 50° C. further for 30 minutes, and then lowered down to 25° C. To this solution was dropwise added a solution obtained by dissolving 135 g (0.8 mol) of 4-n-pentylcyclohexanone in 125 ml of toluene, over 30 minutes, followed by continuing stirring for 30 minutes at 30° C., and then 250 ml of 6 N hydrochloric acid was added dropwise while maintaining the temperature at 30° C. or lower (the first step). The resulting organic layer was separated, 25 g of potassium hydrogen sulfate was added thereto, and after hexane was distilled off with stirring, the resulting residue was concentrated until the liquid temperature reached 110° C. to complete the dehydration reaction (the second step). The resulting concentrate was distilled under a reduced pressure to take a fraction of 160°~170° C./1 mm Hg, whereby there was obtained 160 g of 1-(p-bromophenyl)-4-n-pentylcyclohexene (R=n-C5H11 and n=1 in said formula (B)) (yield: 62.4%), which was then twice recrystallized from ethanol to give a crystal having a melting point of 67°~68° C.

Workup

  1. dissolutiondissolution
  2. temperaturethe temperature was maintained at 50° C. further for 30 minutes
  3. customlowered down to 25° C
  4. additionTo this solution was dropwise added a solution
  5. customobtained
  6. waitover 30 minutes
  7. stirringby continuing stirring for 30 minutes at 30° C.
  8. temperaturewhile maintaining the temperature at 30° C.
  9. customThe resulting organic layer was separated
  10. addition25 g of potassium hydrogen sulfate was added
  11. distillationafter hexane was distilled off
  12. stirringwith stirring
  13. concentrationthe resulting residue was concentrated until the liquid temperature
  14. customreached 110° C.
  15. customthe dehydration reaction (the second step)
  16. concentrationThe resulting concentrate
  17. distillationwas distilled under a reduced pressure
  18. customa fraction of 160°~170° C./1 mm Hg

Sources & evidence

ORD record
ord-ee6238b3c4394d969724c8fc32927afa
Source dataset
uspto-grants-1980_07
Patent number
US04211666

Reaction notes

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