Cyclopentanone → 5-Cyclopentylidenemethylthiophene-2-carbonitrile

HRID 846091Notes

Reaction equation

HRID 846091 reaction equation
Br[CH2:2][C:3]1[S:7][C:6]([C:8]#[N:9])=[CH:5][CH:4]=1.P(OCC)(OCC)OCC.[C:20]1(=O)[CH2:24][CH2:23][CH2:22][CH2:21]1.[H-].[Na+]>O1CCCC1.C1OCCOCCOCCOCCOC1>[C:20]1(=[CH:2][C:3]2[S:7][C:6]([C:8]#[N:9])=[CH:5][CH:4]=2)[CH2:24][CH2:23][CH2:22][CH2:21]1

Participants

7

Reactant 4

HCID 8452CyclopentanoneHCID 24758Sodium hydrideHCID 31215Triethyl phosphiteHCID 105600165-(Bromomethyl)thiophene-2-carbonitrile

Product 1

HCID 199395365-Cyclopentylidenemethylthiophene-2-carbonitrile

Reagents, catalysts & solvents 2

HCID 3633615-Crown-5CatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

In a second process, 20 g of 5-bromomethyl-thiophene-2-carbonitrile is heated with 200 ml of triethyl phosphite for 4 hours to 150°. Then triethyl phosphite is removed at 40°-60°/0.06 mbar, and the residue is distilled on a bulb tube at 130°-150°/0.004 mbar, resulting in 24 g of (5-cyano-2-thienyl)methylphosphonic acid diethyl ester. Of this product, 5 g is added dropwise, with 1.5 ml of cyclopentanone in 5 ml of tetrahydrofuran, to a suspension of 581 mg of sodium hydride/oil (80% strength) and 116 mg of 15-crown-5 in 5 ml of tetrahydrofuran. After 2 hours of agitation at room temperature, the mixture is poured on water and extracted with ethyl acetate. The ethyl acetate phase is dried and evaporated, and the residue is recrystallized from isopropanol, thus obtaining 3.0 g of 5-cyclopentylidenemethylthiophene-2-carbonitrile, identical to the product described above.

Workup

  1. customThen triethyl phosphite is removed at 40°-60°/0.06 mbar
  2. distillationthe residue is distilled on a bulb tube at 130°-150°/0.004 mbar
  3. customresulting in 24 g of (5-cyano-2-thienyl)methylphosphonic acid diethyl ester
  4. additionthe mixture is poured on water
  5. extractionextracted with ethyl acetate
  6. dry with materialThe ethyl acetate phase is dried
  7. customevaporated
  8. customthe residue is recrystallized from isopropanol

Sources & evidence

ORD record
ord-b03c40dbe7e74e5397bde3ff402e2c5f
Source dataset
uspto-grants-1992_08
Patent number
US05135937

Reaction notes

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