Hydrochloric Acid → 3-tert-Butyl-1-ethylcyclopenta-1,3-diene

HRID 423127Notes

Reaction equation

HRID 423127 reaction equation
[CH2:1](OCC)[CH3:2].[C:6]([C:10]1[CH2:14][CH2:13][C:12](=O)[CH:11]=1)([CH3:9])([CH3:8])[CH3:7].Cl>O>[CH2:1]([C:13]1[CH2:12][CH:11]=[C:10]([C:6]([CH3:9])([CH3:8])[CH3:7])[CH:14]=1)[CH3:2]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 3283Diethyl Ether2×HCID 119769972-Cyclopenten-1-one, 3-(1,1-dimethylethyl)-

Product 1

HCID 206271323-tert-Butyl-1-ethylcyclopenta-1,3-dieneYield 78%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A 300 ml three neck flask equipped with a magnetic stirrer and a three-way cock was charged with 200 ml of diethyl ether and 52 ml (154 mmol) of a diethyl ether solution of 3.0-Methylmagnesium bromide under nitrogen atmosphere. 3-tert-Butylcyclopentenone 17.8 g (129 mmol) was added dropwise in one hour on an ice and water bath. The solution was stirred at room temperature for 20 hours, and then the reaction solution was poured into 100 ml of 2N hydrochloric acid. The organic layer was separated, and the aqueous layer was extracted twice with 50 ml of ether. The organic layers thus obtained were combined and washed twice with a saturated sodium hydrogen carbonate aqueous solution, twice with water and twice with a saturated salt solution. The organic layer was dried on magnesium sulfate, and the solvent was removed by distillation. Then, the residue was purified by column chromatography to obtain 20.2 g (GC purity: 75%) of a pale yellow transparent liquid. The yield was 78%. The product was identified by means of a 1H-NMR spectrum. The measurement results thereof are shown below.

Workup

  1. customThe organic layer was separated
  2. extractionthe aqueous layer was extracted twice with 50 ml of ether
  3. customThe organic layers thus obtained
  4. washwashed twice with a saturated sodium hydrogen carbonate aqueous solution, twice with water and twice with a saturated salt solution
  5. customThe organic layer was dried on magnesium sulfate
  6. customthe solvent was removed by distillation
  7. customThen, the residue was purified by column chromatography
  8. customto obtain 20.2 g (GC purity: 75%) of a pale yellow transparent liquid
  9. customThe measurement results

Sources & evidence

ORD record
ord-6928a52f19124ef9b8034aa82bdff856
Source dataset
uspto-grants-2012_01
Patent number
US08101684B2

Reaction notes

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