Реакция #56741

Уравнение реакции

{(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

Растворители

acetic acid ethanol

Условия реакции

Обработка

1. 1
   Температураthe mixture was heated
2. 2
   Температураat reflux under nitrogen for 8 hours
3. 3
   Фильтрацияthe mixture filtered through a pad of celite
4. 4
   Экстракцияextracted with ethyl acetate
5. 5
   СушкаThe extract was dried over magnesium sulfate
6. 6
   Фильтрацияfiltered
7. 7
   Другоеevaporated in vacuum
8. 8
   Другоеchromatographed on silica gel using a gradient elution commencing with 20% ethyl acetate/hexane

Методика

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).

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