Methanol → HCID 58609538, compound

HRID 502912Notes

Reaction equation

HRID 502912 reaction equation
[Cl:1][C:2]1[C:3](=[O:13])[C:4]2([CH3:12])[O:10][C:7]([CH3:11])([C:8]=1Cl)[CH:6]=[CH:5]2.[CH3:14][OH:15].C[O-].[Na+]>CCCCCC.C(OCC)(=O)C>[Cl:1][C:2]1[C:3](=[O:13])[C:4]2([CH3:12])[O:10][C:7]([CH3:11])([C:8]=1[O:15][CH3:14])[CH:6]=[CH:5]2

Participants

5

Reactant 3

HCID 887Methanol2×HCID 10942334Sodium MethoxideHCID 586095253,4-Dichloro-1,5-dimethyl-8-oxa-bicyclo[3.2.1]octa-3,6-dien-2-one

Product 1

HCID 58609538HCID 58609538, compoundYield 52.9%

Reagents, catalysts & solvents 1

HCID 21226206Ethyl acetate hexaneSolvent

Procedure

6.0 g (27.39 mmol) of 3,4-dichloro-1,5-dimethyl-8-oxa-bicyclo[3.2.1]octa-3,6-dien-2-one is introduced into 39 ml of anhydrous methanol. At a temperature of 0° C., the reaction mixture is further diluted dropwise with a solution of 15.2 ml of 5.4M sodium methanolate (82.17 mmol) and treated with 10 ml of absolute methanol. The reaction mixture is then heated to ambient temperature with 35 minutes' stirring. Using thin-layer chromatography (hexane/ethyl acetate 8:2) it can be established that reaction of the starting material is complete. The reaction solution is then concentrated under reduced pressure. The residue is then extracted by means of carbon tetrachloride against water. The aqueous phase is extracted a further three times using fresh carbon tetrachloride. The combined organic extracts are dried over sodium sulfate and concentrated by evaporation under reduced pressure; with ice-cooling, the oily product that remains behind crystallises out in the form of a ˜1:1 mixture. The mixture is separated by means of column chromatography on silica gel (eluant: gradient from 1-5% ethyl acetate/hexane). 3.1 g (52.9%) of pure 3-chloro-1,5-dimethyl-4-methoxy-8-oxa-bicyclo[3.2.1]octa-3,6-dien-2-one are isolated.

Workup

  1. concentrationThe reaction solution is then concentrated under reduced pressure
  2. extractionThe residue is then extracted by means of carbon tetrachloride against water
  3. extractionThe aqueous phase is extracted a further three times
  4. dry with materialThe combined organic extracts are dried over sodium sulfate
  5. concentrationconcentrated by evaporation under reduced pressure
  6. temperaturewith ice-cooling
  7. custombehind crystallises out in the form of a ˜1:1 mixture
  8. customThe mixture is separated by means of column chromatography on silica gel (eluant: gradient from 1-5% ethyl acetate/hexane)

Sources & evidence

ORD record
ord-6d2ce984546e4e81b6a144859bf0b749
Source dataset
uspto-grants-2010_08
Patent number
US07776888B2

Reaction notes

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