Water → (8-Methyl-2,3-dihydro[1,4]dioxino[2,3-f]quinolin-2-yl)methyl 4-methylbenzene-1-sulfonate

HRID 28463Notes

Reaction equation

HRID 28463 reaction equation
[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([S:8]([O:11][CH2:12][C@@H:13]2[O:18][C:17]3[C:19](/[CH:26]=[CH:27]/[C:28](=O)[CH3:29])=[C:20]([N+:23]([O-])=O)[CH:21]=[CH:22][C:16]=3[O:15][CH2:14]2)(=[O:10])=[O:9])=[CH:4][CH:3]=1.O>C(O)(=O)C.C(O)C.[Fe]>[CH3:1][C:2]1[CH:3]=[CH:4][C:5]([S:8]([O:11][CH2:12][CH:13]2[O:18][C:17]3=[C:19]4[C:20](=[CH:21][CH:22]=[C:16]3[O:15][CH2:14]2)[N:23]=[C:28]([CH3:29])[CH:27]=[CH:26]4)(=[O:10])=[O:9])=[CH:6][CH:7]=1

Participants

5

Reactant 2

HCID 962WaterHCID 12082210{(2R)-7-nitro-8-[(E)-3-oxo-1-butenyl]-2,3-dihydro-1,4-benzodioxin-2-yl}methyl 4-methylbenzenesulfonate

Product 1

HCID 21892063(8-Methyl-2,3-dihydro[1,4]dioxino[2,3-f]quinolin-2-yl)methyl 4-methylbenzene-1-sulfonate

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 18476134Acetic acid ethanolSolvent

Procedure

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).

Workup

  1. temperaturethe mixture was heated
  2. temperatureat reflux under nitrogen for 8 hours
  3. filtrationthe mixture filtered through a pad of celite
  4. extractionextracted with ethyl acetate
  5. dry with materialThe extract was dried over magnesium sulfate
  6. filtrationfiltered
  7. customevaporated in vacuum
  8. customchromatographed on silica gel using a gradient elution commencing with 20% ethyl acetate/hexane

Sources & evidence

ORD record
ord-1e32d2dbac424e00a468399d199295c1
Source dataset
uspto-grants-2008_09
Patent number
US07419986B2

Reaction notes

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