Malononitrile → Dihydro-2H-pyran-4,4(3H)-dicarbonitrile

HRID 1024367Notes

Reaction equation

HRID 1024367 reaction equation
[C:1](#[N:5])[CH2:2][C:3]#[N:4].Br[CH2:7][CH2:8][O:9][CH2:10][CH2:11]Br.CC([O-])(C)C.[K+]>CS(C)=O.CCCC[N+](CCCC)(CCCC)CCCC.[Br-].C(Cl)Cl>[O:9]1[CH2:10][CH2:11][C:2]([C:1]#[N:5])([C:3]#[N:4])[CH2:7][CH2:8]1

Participants

7

Reactant 3

HCID 8010MalononitrileHCID 21521Bis(2-bromoethyl) etherHCID 23665647Potassium tert-butoxide

Product 1

HCID 14537194Dihydro-2H-pyran-4,4(3H)-dicarbonitrileYield 24%

Reagents, catalysts & solvents 3

HCID 74236Tetrabutylammonium BromideCatalystHCID 679Dimethyl SulfoxideSolventHCID 6344DichloromethaneSolvent

Procedure

Malononitrile (5.0 g) was dissolved in DMSO (5 mL). Subsequently, bis(2-bromoethyl)ether (9.49 mL) and TBAB (1.22 g) were added, followed by portionwise addition of KOtBu (8.49 g). The mixture was stirred for 4 h. at room temperature, taken up in DCM and extracted 3 times with 5% aqueous NaHCO3. The organic phase was dried over Na2SO4 and evaporated under reduced pressure. The crude material was purified by flash chromatography eluting with PA:Et2O 65:35 (Rf=0.24, visualized with KMnO4) to give 2.49 g (24%) of a solid. 1H NMR (400 MHz, CDCl3) δ 2.24 (t, 4H), 3.87 (t, 4H).

Workup

  1. extractionextracted 3 times with 5% aqueous NaHCO3
  2. dry with materialThe organic phase was dried over Na2SO4
  3. customevaporated under reduced pressure
  4. customThe crude material was purified by flash chromatography
  5. washeluting with PA

Sources & evidence

ORD record
ord-9e38c6186cdc4b7b863efe8f93ac714e
Source dataset
uspto-grants-2014_05
Patent number
US08722887B2

Reaction notes

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