Diethyl (cyanomethyl)phosphonate → (2E)-3-[5-(diethoxymethyl)-3-thienyl]acrylonitrile

HRID 1962747Notes

Reaction equation

HRID 1962747 reaction equation
[C:1]([CH2:3]P(=O)(OCC)OCC)#[N:2].CC(C)([O-])C.[K+].[CH2:18]([O:20][CH:21]([O:29][CH2:30][CH3:31])[C:22]1[S:26][CH:25]=[C:24]([CH:27]=O)[CH:23]=1)[CH3:19]>C1COCC1>[CH2:18]([O:20][CH:21]([O:29][CH2:30][CH3:31])[C:22]1[S:26][CH:25]=[C:24](/[CH:27]=[CH:3]/[C:1]#[N:2])[CH:23]=1)[CH3:19]

Participants

5

Reactant 3

HCID 75676Diethyl (cyanomethyl)phosphonateHCID 122800635-(Diethoxymethyl)thiophene-3-carbaldehydeHCID 23665647Potassium tert-butoxide

Product 1

HCID 66597856(2E)-3-[5-(diethoxymethyl)-3-thienyl]acrylonitrileYield 85.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

To a solution of diethyl cyanomethylphosphonate (100 mg, 0.0008 mol) in THF (2 mL, 0.02 mol) cooled at 0° C. and 1.0 M potassium tert-butoxide in THF (0.8 mL) was added dropwise. The bath was removed and the reaction was warmed to room temperature for 30 minutes. The reaction was cooled to 0° C. and a solution of 5-(diethoxymethyl)thiophene-3-carbaldehyde (170 mg, 0.00079 mol) in THF (2 mL, 0.02 mol) was added drop wise. The reaction was stirred overnight at room temperature. The reaction was partitioned between water and ethyl acetate. The combined extracts were washed with saturated sodium chloride, dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by flash column chromatography on silica gel eluting (ethyl acetate:hexane, 1:5) to give (2E)-3-[5-(diethoxymethyl)-3-thienyl]acrylonitrile as an oil (160 mg, 84.9%). 1H NMR (300 MHz, CDCl3): 7.4-7.0 (m, 3H), 5.65 (m 1H), 4.2 (m, 1H), 3.65 (m, 4H), 1.25 (m, 6H).

Workup

  1. customThe bath was removed
  2. temperatureThe reaction was cooled to 0° C.
  3. customThe reaction was partitioned between water and ethyl acetate
  4. washThe combined extracts were washed with saturated sodium chloride
  5. dry with materialdried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe crude residue was purified by flash column chromatography on silica gel eluting (ethyl acetate:hexane, 1:5)

Sources & evidence

ORD record
ord-208cb4864300432dae54ee1ca5fa6ef6
Source dataset
uspto-grants-2013_04
Patent number
US08415362B2

Reaction notes

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