2-Bromopentane → HCID 54128579, compound

HRID 1381077Notes

Reaction equation

HRID 1381077 reaction equation
[Mg].Br[CH:3]([CH2:5][CH2:6][CH3:7])[CH3:4].[CH3:8][C:9](=[CH:12][CH2:13][CH3:14])[CH:10]=[O:11].[Cl-].[NH4+]>CCOCC>[CH3:4][C:3]([CH:10]([OH:11])[CH:9]([CH3:8])[CH2:12][CH2:13][CH3:14])=[CH:5][CH2:6][CH3:7]

Participants

6

Reactant 4

HCID 78902-BromopentaneHCID 121772-Methyl-2-pentenalHCID 25517Ammonium ChlorideHCID 5462224Magnesium

Product 1

HCID 54128579HCID 54128579, compound

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent4×

Conditions

Temperature
10 °C

Procedure

28.3 g (1.18 g atoms) of magnesium in 200 ml of ether are placed in an apparatus which is customary for Grignard reactions. While stirring and under a protective gas atmosphere (nitrogen) there are subsequently added dropwise 178.1 g (1.18 mol) of 2-bromopentane in 500 ml of absolute ether so that, after initiation of the reaction, the ether constantly boils slightly. After completing the addition, the mixture is held at reflux temperature for a further 30 minutes, then cooled to 10° C. and a solution of 96.1 g (0.98 mol) of 2-methyl-2-pentenal in 300 ml of ether is added dropwise during 30 minutes so that the reaction temperature during the addition lies between 10° and 20° C. In order to complete the reaction, the mixture is refluxed for 1 hour, then the Grignard complex is decomposed with saturated ammonium chloride solution and ice, the supernatant ethereal solution is washed with saturated sodium chloride solution and subsequently dried. After evaporating the solvent, there remain behind 176 g of crude product, which are fractionally distilled. There are thus obtained 119 g (71.4%) of olfactorily good 4,6-dimethyl-3-nonen-5-ol of boiling point 92° C./12 mm Hg.

Workup

  1. customafter initiation of the reaction
  2. additionthe addition
  3. temperatureat reflux temperature for a further 30 minutes
  4. customlies between 10° and 20° C
  5. customthe reaction
  6. temperaturethe mixture is refluxed for 1 hour
  7. washthe supernatant ethereal solution is washed with saturated sodium chloride solution
  8. customsubsequently dried
  9. customAfter evaporating the solvent, there
  10. distillationare fractionally distilled

Sources & evidence

ORD record
ord-d533676d93e54d0db17df35d9ee931e4
Source dataset
uspto-grants-1986_04
Patent number
US04585662

Reaction notes

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