Dimethylformamide → 1,1-Bis(propan-2-yl) 3,3-dimethoxycyclobutane-1,1-dicarboxylate

HRID 539973Notes

Reaction equation

HRID 539973 reaction equation
[H-].[Na+].[C:3]([O:12][CH:13]([CH3:15])[CH3:14])(=[O:11])[CH2:4][C:5]([O:7][CH:8]([CH3:10])[CH3:9])=[O:6].[H][H].[Cl-].[NH4+].CN(C)[CH:22]=[O:23]>>[CH3:5][O:7][C:8]1([O:23][CH3:22])[CH2:10][C:4]([C:5]([O:7][CH:8]([CH3:9])[CH3:10])=[O:6])([C:3]([O:12][CH:13]([CH3:15])[CH3:14])=[O:11])[CH2:9]1

Participants

6

Reactant 5

HCID 6228DimethylformamideHCID 24758Sodium hydrideHCID 25517Ammonium ChlorideHCID 83223Diisopropyl malonateHCID 178418361HCID 178418361, compound

Product 1

HCID 49133591,1-Bis(propan-2-yl) 3,3-dimethoxycyclobutane-1,1-dicarboxylateYield 58.2%

Procedure

To a stirred suspension of sodium hydride (96.5 g, 2.413 mol, 60% in mineral oil) in dry N,N-dimethylformamide (900 ml) was added 1,3-bis(propan-2-yl) propanedioate (363.3 g, 1.930 mol) dropwise under nitrogen at a rate such that the temperature was maintained below 70° C. On cessation of hydrogen evolution, the mixture was heated to 130° C., to 3-dibromo-2,2-dimethoxypropane (252.8 g, 0.965 mol) was then introduced in one portion. The mixture was heated under reflux for 48 hours. The cooled mixture was poured into a saturated aqueous solution of ammonium chloride (300 mL) and extracted with methyl tert-butyl ether (300 mL). The organic layer was washed with a saturated aqueous solution of sodium bicarbonate and brine, dried over sodium sulfate, and concentrated in vacuo. The residue was distilled in vacuo (oil pump) to afford 52.7 g of dipropan-2-yl 3,3-dimethoxycyclobutane-1,1-dicarboxylate as a colorless oil (yield was 58.2%). 1H NMR (400 MHz, CDCl3) δ ppm 5.02 (m J=6.4 Hz, 2 H), 3.12 (s, 6 H), 2.66 (s, 4 H), 1.11 (d, J=6.4 Hz, 12 H).

Workup

  1. temperaturewas maintained below 70° C
  2. additionwas then introduced in one portion
  3. temperatureThe mixture was heated
  4. temperatureunder reflux for 48 hours
  5. extractionextracted with methyl tert-butyl ether (300 mL)
  6. washThe organic layer was washed with a saturated aqueous solution of sodium bicarbonate and brine
  7. dry with materialdried over sodium sulfate
  8. concentrationconcentrated in vacuo
  9. distillationThe residue was distilled in vacuo (oil pump)

Sources & evidence

ORD record
ord-cf6d649bdfaf4406ada9588aef0dc999
Source dataset
uspto-grants-2014_10
Patent number
US08871756B2

Reaction notes

Loading…