2,2-Dimethylchroman → 2,2-Dimethylchroman-8-carboxylic acid

HRID 358827

Reaktionsgleichung

Reaktionsgleichung von HRID 358827
C([Li])CCC.[CH3:6][C:7]1([CH3:17])[CH2:16][CH2:15][C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[O:8]1.[C:18](=[O:20])=[O:19].C(OCC)C>CCCCCC.C(OCC)C>[CH3:6][C:7]1([CH3:17])[CH2:16][CH2:15][C:14]2[C:9](=[C:10]([C:18]([OH:20])=[O:19])[CH:11]=[CH:12][CH:13]=2)[O:8]1

Komponenten

6

Edukt 3

HCID 1369362,2-DimethylchromanHCID 86742199Dry ice diethyl etherHCID 178418339Butyllithium

Produkt 1

HCID 130516922,2-Dimethylchroman-8-carboxylic acid

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 3283Diethyl EtherLösungsmittel2×HCID 8058HexaneLösungsmittel

Versuchsvorschrift

To a solution of 1.6M n-butyllithium in hexane and 150 ml of diethyl ether were added a solution of 27 g of 2,2-dimethylchroman in diethyl ether over a one hour period at room temperature. The solution was then heated at reflux 160 minutes, cooled, and poured into dry ice/diethyl ether. The mixture was allowed to come to room temperature, poured into ice water, and layers separated. The organic layer was washed with water, dried over sodium sulfate, and concentrated in vacuo to provide 21 g of solid. The aqueous layer was acidified and the resulting precipitate extracted into diethyl ether/ethyl acetate. The organic extract was washed with water, dried over sodium sulfate, and concentrated in vacuo to provide 9 g of solid. The two isolated solids were combined and chromatographed over silica gel eluting with 10% ethyl acetate in toluene. The appropriate fractions were combined and concentrated in vacuo to provide 9.8 g of the desired title intermediate, m.p. 90°-92° C.

Aufarbeitung

  1. temperatureThe solution was then heated
  2. temperatureat reflux 160 minutes
  3. temperaturecooled
  4. customto come to room temperature
  5. customseparated
  6. washThe organic layer was washed with water
  7. dry with materialdried over sodium sulfate
  8. concentrationconcentrated in vacuo

Quellen und Nachweise

ORD-Eintrag
ord-6508e1cde9e44854aadd694b06a4aabc
Quelldatensatz
uspto-grants-1991_03
Patentnummer
US04997956

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