Carbon Dioxide → 2,3-Dihydro-1-benzofuran-7-carboxylic acid

HRID 440512

Reaktionsgleichung

Reaktionsgleichung von HRID 440512
CN(C)CCN(C)C.C([Li])CCC.[O:14]1[CH2:18][CH2:17][C:16]2[CH:19]=[CH:20][CH:21]=[CH:22][C:15]1=2.[C:23](=[O:25])=[O:24]>CCCCCC.O>[O:14]1[CH2:18][CH2:17][C:16]2[CH:19]=[CH:20][CH:21]=[C:22]([C:23]([OH:25])=[O:24])[C:15]1=2

Komponenten

7

Edukt 4

HCID 280Carbon DioxideHCID 8037N,N,N',N'-TetramethylethylenediamineHCID 10329DihydrobenzofuranHCID 178418339Butyllithium

Produkt 1

HCID 27950142,3-Dihydro-1-benzofuran-7-carboxylic acidAusbeute 28,4 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 962WaterLösungsmittelHCID 8058HexaneLösungsmittel3×

Versuchsvorschrift

N,N,N',N'-Tetramethylethylenediamine (231.4 g) was added at ambient temperature to a solution of n-butyl lithium (2.5M, 800 ml) in hexane (2.5 l) followed by a solution of 2,3-dihydrobenzo[b]furan (102 g) in hexane (25 ml). The mixture was stirred under nitrogen at ambient temperature for 5 hours. The resulting suspension was added slowly to dry ice (300 g) and hexane (500 ml) under nitrogen. After stirring at ambient temperature for 16 hours, the mixture was diluted with water (2 l), and the layers separated. The aqueous layer was washed with hexane, acidified to pH 1 with concentrated hydrochloric acid, cooled and the precipitate collected by filtration. This was washed with water and dichloromethane and dried at 80° C. in vacuo to give 2,3-dihydrobenzo[b]furan-7-carboxylic acid (39.6 g), m.p. 164°-165° C. The hexane layer was filtered, dried over sodium sulphate and concentrated. On cooling, further product was obtained (32.7 g), m.p. 170° C.

Aufarbeitung

  1. stirringAfter stirring at ambient temperature for 16 hours
  2. customthe layers separated
  3. washThe aqueous layer was washed with hexane
  4. temperaturecooled
  5. filtrationthe precipitate collected by filtration
  6. washThis was washed with water and dichloromethane
  7. customdried at 80° C. in vacuo

Quellen und Nachweise

ORD-Eintrag
ord-abf77135cf584e258ffec244dcfb972a
Quelldatensatz
uspto-grants-1996_05
Patentnummer
US05519034

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