Phosphoric Acid → Cyclohexene, 1-(2-methylpropyl)-

HRID 2059549Notes

Reaction equation

HRID 2059549 reaction equation
[CH2:1]([C:5]1(O)[CH2:10][CH2:9][CH2:8][CH2:7][CH2:6]1)[CH:2]([CH3:4])[CH3:3].P(=O)(O)(O)O>>[CH2:1]([C:5]1[CH2:10][CH2:9][CH2:8][CH2:7][CH:6]=1)[CH:2]([CH3:4])[CH3:3]

Participants

3

Reactant 2

HCID 1004Phosphoric Acid2×HCID 1111630468366-16-52×

Product 1

HCID 138091Cyclohexene, 1-(2-methylpropyl)-Yield 253.2%

Conditions

Temperature
145 °C

Procedure

In a flask equipped with a Vigreux-distillation apparatus, crude 1-isobutylcyclohexanol (200 g, 1.28 mol) was treated with phosphoric acid (100 g) and heated at 145° C. under vacuum (170 mbar). While 1-isobutylcyclohex-1-ene and water distilled (boiling point 60° C.), a second fraction of 1-isobutylcyclohexanol (492 g, 3.15 mol) was added dropwise in the reaction flask. At the end of the addition, the thick reaction mixture was diluted with paraffin oil (100 ml) and additional phosphoric acid (50 g) and heated further (vacuum from 170 to 40 mbar). The distillate was decanted and the water phase extracted with pentane (100 ml). The combined org. phases were dried (MgSO4) and the solvent evaporated to give 1-isobutylcyclohex-1-ene (448 g, 78%).

Workup

  1. distillationWhile 1-isobutylcyclohex-1-ene and water distilled (boiling point 60° C.)
  2. additionAt the end of the addition
  3. temperatureheated further (vacuum from 170 to 40 mbar)
  4. customThe distillate was decanted
  5. extractionthe water phase extracted with pentane (100 ml)
  6. dry with materialphases were dried (MgSO4)
  7. customthe solvent evaporated

Sources & evidence

ORD record
ord-1e916d4e583643b9944126dba06f1220
Source dataset
uspto-grants-2012_10
Patent number
US08278230B2

Reaction notes

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