Sodium Hydroxide → 2-Bromo-5,5-dimethylcyclohex-1-enecarbaldehyde

HRID 410339Notes

Reaction equation

HRID 410339 reaction equation
[OH-].[Na+].P(Br)(Br)[Br:4].[CH3:7][C:8]1([CH3:15])[CH2:13][CH2:12][C:11](=O)[CH2:10][CH2:9]1.[C:16]([O-:19])(=O)C.[Na+]>CN(C)C=O.C(Cl)(Cl)Cl>[Br:4][C:11]1[CH2:12][CH2:13][C:8]([CH3:15])([CH3:7])[CH2:9][C:10]=1[CH:16]=[O:19]

Participants

7

Reactant 4

HCID 14798Sodium Hydroxide2×HCID 24614Phosphorus tribromideHCID 138166Cyclohexanone, 4,4-dimethyl-HCID 517045Sodium Acetate

Product 1

HCID 251391912-Bromo-5,5-dimethylcyclohex-1-enecarbaldehydeYield 58%

Reagents, catalysts & solvents 2

HCID 6212ChloroformSolventHCID 6228DimethylformamideSolvent

Conditions

Temperature
3 °C

Procedure

A 3-necked round bottom flask equipped with a nitrogen inlet, a thermometer and an outlet connected to a scrubber containing a solution of 2M NaOH was charged with anhydrous chloroform (15 ml) and anhydrous N,N-dimethylformamide (2.5 ml (32.3 mmol). The solution was cooled to ˜3° C. (internal temperature) under nitrogen before phosphorus tribromide (2.8 ml, 30.0 mmol) was introduced dropwise at a rate so that the reaction was maintained at ˜3° C. After the addition was complete the reaction was allowed to warm slowly to ˜10° C. and then the temperature was raised to 70° C. where it was maintained for 30 min. The reaction was cooled to rt and 4,4-dimethylcyclohexanone (1.4 g, 11.1 mmol) was added slowly over 20 min. After the addition was complete the reaction was warmed to 70° C. and it was stirred for 1.5 h. The mixture was then cooled to rt and poured onto a solution of 4M sodium acetate (15 ml). The pH of the resulting solution was adjusted to ˜7 using a solution of 5M NaOH and the mixture was then extracted with heptanes (×5). The combined organic fractions were dried (Na2SO4), filtered and concentrated under reduced pressure to give 2-bromo-5,5-dimethyl-cyclohex-1-ene carbaldehyde as a yellow oil (1.4 g, 58%). 1H NMR (MeOD) □ 10.05 (1H, s), 2.82 (2H, m), 2.10 (2H, m), 1.59 (2H, t), 0.96 (6H, s).

Workup

  1. customA 3-necked round bottom flask equipped with a nitrogen inlet
  2. additionwas introduced dropwise at a rate so that the reaction
  3. additionAfter the addition
  4. temperatureto warm slowly to ˜10° C.
  5. temperaturethe temperature was raised to 70° C. where it
  6. temperaturewas maintained for 30 min
  7. temperatureThe reaction was cooled to rt
  8. additionAfter the addition
  9. temperaturewas warmed to 70° C.
  10. temperatureThe mixture was then cooled to rt
  11. extractionthe mixture was then extracted with heptanes (×5)
  12. dry with materialThe combined organic fractions were dried (Na2SO4)
  13. filtrationfiltered
  14. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-27bfdad7bed54bd7a3cfc4a0e0602c08
Source dataset
uspto-grants-2014_06
Patent number
US08759520B2

Reaction notes

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