Reaktion #56741

Reaktionsgleichung

{(2R)-7-nitro-8-[(E)-3-oxo-1-butenyl]-2,3-dihydro-1,4-benzodioxin-2-yl}methyl 4-methylbenzenesulfonate

water

→

title compound

(8-Methyl-2,3-dihydro[1,4]dioxino[2,3-f]quinolin-2-yl)methyl 4-methylbenzenesulfonate

Lösungsmittel

acetic acid ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture was heated
2. 2
   Temperaturat reflux under nitrogen for 8 hours
3. 3
   Filtrationthe mixture filtered through a pad of celite
4. 4
   Extraktionextracted with ethyl acetate
5. 5
   TrocknenThe extract was dried over magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   Sonstigeevaporated in vacuum
8. 8
   Sonstigechromatographed on silica gel using a gradient elution commencing with 20% ethyl acetate/hexane

Vorschrift

To a solution of {(2R)-7-nitro-8-[(E)-3-oxo-1-butenyl]-2,3-dihydro-1,4-benzodioxin-2-yl}methyl 4-methylbenzenesulfonate (3.40 g, 7.83 mmole) in 200 mL of acetic acid/ethanol (3:2) was added 2.25 g (40.2 mmole) of iron powder and the mixture was heated at reflux under nitrogen for 8 hours. After the reaction was complete, 150 mL of water was added and the mixture filtered through a pad of celite. The filtrate was neutralized with saturated aqueous sodium bicarbonate and extracted with ethyl acetate. The extract was dried over magnesium sulfate, filtered, and evaporated in vacuum. The residue was column chromatographed on silica gel using a gradient elution commencing with 20% ethyl acetate/hexane and ending with 70% ethyl acetate/hexane to give 2.5 g of the (R)-enantiomer of the title compound as a yellow oil. 1H-NMR (CDCl3): doublet 8.1 δ (1 H); doublet 7.6 δ (2 H) doublet 7.45 δ (1 H); multiplet 7.2 δ (4 H); multiplet 4.6 δ (1 H); multiplet 4.3 δ (3 H); multiplet 4.1 δ (1 H); singlet 2.5 δ (3 H); singlet 2.4 δ (3 H).

Quelle