Sulfuric Acid → HCID 20089256, compound

HRID 274887Notes

Reaction equation

HRID 274887 reaction equation
Br[CH2:2][C:3]([O:5][CH2:6][CH3:7])=[O:4].[C:8]([C:11]1[CH2:12][O:13][C:14]2[C:19]([CH:20]=1)=[CH:18][C:17]([C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)=[CH:16][CH:15]=2)(=[O:10])[CH3:9].S(=O)(=O)(O)O.C(OCC)C>COCOC.O1CCCC1.[Zn]>[OH:10][C:8]([C:11]1[CH2:12][O:13][C:14]2[C:19]([CH:20]=1)=[CH:18][C:17]([C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)=[CH:16][CH:15]=2)([CH3:9])[CH2:2][C:3]([O:5][CH2:6][CH3:7])=[O:4]

Participants

8

Reactant 4

HCID 1118Sulfuric AcidHCID 3283Diethyl EtherHCID 7748Ethyl bromoacetate2×HCID 20089233HCID 20089233, compound

Product 1

HCID 20089256HCID 20089256, compound

Reagents, catalysts & solvents 3

HCID 23994ZincCatalystHCID 8020DimethoxymethaneSolvent2×HCID 8028TetrahydrofuranSolvent

Procedure

4.35 g (0.0665 At-g) of activated zinc are covered with 12 ml of dimethoxymethane, and then 1 ml (9 mmol) of pure ethyl bromoacetate is added under an argon atmosphere. After induction of the reaction by heating, a solution of 6.38 ml (57.5 mmol) of ethyl bromoacetate in 20 ml of dimethoxymethane is added in such a manner as to maintain reflux. After the zinc has been completely consumed and the reaction mixture has returned to room temperature, a solution of 11.1 g (43.5 mmol) of 3-acetyl-6-phenyl-2H-chromene in 60 ml of anhydrous tetrahydrofuran is added dropwise over a period of from 10 to 15 minutes. After one hour's stirring at room temperature, the mixture, cooled to +4° C., is treated with 25 ml of a 10% sulphuric acid solution. After addition of 70 ml of diethyl ether, the aqueous phase is separated off, and the ethereal phase is washed with 3×20 ml of water and then dried over magnesium sulphate. The solvents are evaporated off under reduced pressure, yielding a solid which is used in the following step without additional purification.

Workup

  1. customAfter induction of the reaction
  2. temperatureby heating
  3. temperatureto maintain
  4. temperaturereflux
  5. customAfter the zinc has been completely consumed
  6. customhas returned to room temperature
  7. temperaturethe mixture, cooled to +4° C.
  8. customthe aqueous phase is separated off
  9. washthe ethereal phase is washed with 3×20 ml of water
  10. dry with materialdried over magnesium sulphate
  11. customThe solvents are evaporated off under reduced pressure
  12. customyielding a solid which
  13. customis used in the following step without additional purification

Sources & evidence

ORD record
ord-819bbc1774bc44bf934c6436ea4634d3
Source dataset
uspto-grants-1995_02
Patent number
US05391569

Reaction notes

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