Reaktion #9404

Reaktionsgleichung

21

2, 3-dihydroxy-4-methoxybenzaldehyde

K2CO3

Water

EtOAc

2-bromopropane

→

aldehyde

Ausbeute 82.0%

2,3-diisopropoxy-4-methoxybenzaldehyde

Ausbeute 82.0%

Lösungsmittel

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturheated
2. 2
   Sonstigethe phases were separated
3. 3
   Extraktionthe aqueous phase was extracted with EtOAc (3×200 mL)
4. 4
   TrocknenThe combined organic solutions were dried over MgSO4
5. 5
   Einengenconcentrated under reduced pressure
6. 6
   SonstigePurification
7. 7
   Waschenby flash column chromatography (silica gel, elution with hexane)

Vorschrift

To a solution of 21 (26.70 g, 158.7 mmol) in DMF (150 mL) under nitrogen, was added K2CO3 (65.84 g, 476.3 mmol) followed by 2-bromopropane (44.72 mL, 476.3 mmol) and heated to reflux (90° C.) for 12 hours. Water (200 mL) and EtOAc (200 mL) were added to the reaction mixture, the phases were separated, and the aqueous phase was extracted with EtOAc (3×200 mL). The combined organic solutions were dried over MgSO4 and concentrated under reduced pressure. Purification by flash column chromatography (silica gel, elution with hexane) provided 32.85 g (1.30.2 mmol, 82%) of the diusopropyl-protected aldehyde 22 as a yellow oil.

Quelle