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

HRID 1692933

Reaction equation

HRID 1692933 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-f81beaf1aaf14676b664d6b9fc5ec6d6
Source dataset
uspto-grants-2012_04
Patent number
US08158616B2

Linked notes

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