Carbon Dioxide → HCID 18370915, compound

HRID 1429089Notes

Reaction equation

HRID 1429089 reaction equation
[O:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[CH:3]=[CH:2]1.C(=O)=O.[Li]CCCC.[C:18](OCC)(=[O:24])[C:19]([O:21][CH2:22][CH3:23])=[O:20]>O1CCCC1.CCOCC>[O:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[CH:3]=[C:2]1[C:18](=[O:24])[C:19]([O:21][CH2:22][CH3:23])=[O:20]

Participants

7

Reactant 4

HCID 280Carbon DioxideHCID 7268Diethyl OxalateHCID 9223BenzofuranHCID 178418339Butyllithium

Product 1

HCID 18370915HCID 18370915, compoundYield 47%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of benzofuran (0.250 mL, 2.32 mmol) in tetrahydrofuran (12.5 mL) stiffing at −100° C. (CO2, ether bath) was added n-BuLi (1.377 mL, 2.203 mmol, 1.6 M in hexanes). The reaction was stirred for 30 min (yellow color) and added dropwise via a canulated into a solution of diethyl oxalate (0.314 mL, 2.32 mmol) in tetrahydrofuran (7 mL) stiffing at −100° C. The reaction mixture was stirred for 1 h and then quenched with saturated aqueous ammonium chloride solution. The mixture was warmed to rt, diluted with dichloromethane, and washed with 0.1 N HCl. The organic layer was separated, dried over anhydrous magnesium sulfate, filtered, and evaporated under reduced pressure. The residue was purified by flash chromatography on silica gel (eluted with dichloromethane). The fractions containing the title compound were collected and repurified by flash chromatography on silica gel (25% acetone/hexane) to provide the title compound (ethyl 2-(benzofuran-2-yl)-2-oxoacetate, 237 mg, 47% yield).

Workup

  1. customstiffing at −100° C.
  2. additionadded dropwise via
  3. customstiffing at −100° C
  4. stirringThe reaction mixture was stirred for 1 h
  5. customquenched with saturated aqueous ammonium chloride solution
  6. additiondiluted with dichloromethane
  7. washwashed with 0.1 N HCl
  8. customThe organic layer was separated
  9. dry with materialdried over anhydrous magnesium sulfate
  10. filtrationfiltered
  11. customevaporated under reduced pressure
  12. customThe residue was purified by flash chromatography on silica gel (eluted with dichloromethane)
  13. additionThe fractions containing the title compound
  14. customwere collected
  15. customrepurified by flash chromatography on silica gel (25% acetone/hexane)

Sources & evidence

ORD record
ord-f88718781f1e4173a7412ef40a20face
Source dataset
uspto-grants-2015_01
Patent number
US08937041B2

Reaction notes

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