Diethyl (cyanomethyl)phosphonate → Diisopropyl 3-(cyanomethylene)cyclobutane-1,1-dicarboxylate

HRID 1966159Notes

Reaction equation

HRID 1966159 reaction equation
CC(C)([O-])C.[K+].[C:7]([CH2:9]P(=O)(OCC)OCC)#[N:8].O=[C:19]1[CH2:22][C:21]([C:29]([O:31][CH:32]([CH3:34])[CH3:33])=[O:30])([C:23]([O:25][CH:26]([CH3:28])[CH3:27])=[O:24])[CH2:20]1>O1CCCC1>[C:7]([CH:9]=[C:19]1[CH2:22][C:21]([C:29]([O:31][CH:32]([CH3:34])[CH3:33])=[O:30])([C:23]([O:25][CH:26]([CH3:28])[CH3:27])=[O:24])[CH2:20]1)#[N:8]

Participants

5

Reactant 3

HCID 75676Diethyl (cyanomethyl)phosphonateHCID 49133571,1-Bis(propan-2-yl) 3-oxocyclobutane-1,1-dicarboxylateHCID 23665647Potassium tert-butoxide

Product 1

HCID 66823993Diisopropyl 3-(cyanomethylene)cyclobutane-1,1-dicarboxylateYield 90.8%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

To a mixture of 1.0000 M of potassium tert-butoxide in tetrahydrofuran (17 mL) and THF (10 mL) was added dropwise, at 0° C., diethyl cyanomethylphosphonate (2.7 mL, 0.017 mol). The reaction was warmed to rt and 30 min later cooled to 0° C. again. To the reaction mixture was added a solution of diisopropyl 3-oxocyclobutane-1,1-dicarboxylate (2.7 g, 0.011 mol) in THF (10 mL). The reaction was allowed to warm up to rt gradually and stirred at rt for 2 h. The reaction was quenched with saturated aq. NH4Cl and the organic solvent was reduced. The mixture was extracted with EtOAc. The combined organic layers were washed with brine, dried over MgSO4, concentrated and purified with Combiflash (silica gel, 0-35% EtOAc/Hex) to give the desired product (2.65 g) as light yellow oil.

Workup

  1. additionwas added dropwise, at 0° C.
  2. temperaturelater cooled to 0° C. again
  3. temperatureto warm up to rt gradually
  4. customThe reaction was quenched with saturated aq. NH4Cl
  5. extractionThe mixture was extracted with EtOAc
  6. washThe combined organic layers were washed with brine
  7. dry with materialdried over MgSO4
  8. concentrationconcentrated
  9. custompurified with Combiflash (silica gel, 0-35% EtOAc/Hex)

Sources & evidence

ORD record
ord-bdfe24814a8b481bbee138337cd49553
Source dataset
uspto-grants-2013_04
Patent number
US08420629B2

Reaction notes

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