Ethylene Glycol → 3-Methoxy-8-(2-methyl-[1,3]-dioxolan-2-yl)-benzo[c]chromen-6-one

HRID 987591Notes

Reaction equation

HRID 987591 reaction equation
[C:1]([C:4]1[CH:5]=[CH:6][C:7]2[C:16]3[C:11](=[CH:12][C:13]([O:17][CH3:18])=[CH:14][CH:15]=3)[O:10][C:9](=[O:19])[C:8]=2[CH:20]=1)(=[O:3])[CH3:2].[CH2:21](O)[CH2:22][OH:23].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1>[CH3:18][O:17][C:13]1[CH:12]=[C:11]2[C:16]([C:7]3[CH:6]=[CH:5][C:4]([C:1]4([CH3:2])[O:23][CH2:22][CH2:21][O:3]4)=[CH:20][C:8]=3[C:9](=[O:19])[O:10]2)=[CH:15][CH:14]=1

Participants

5

Reactant 3

HCID 174Ethylene GlycolHCID 6101p-Toluenesulfonic acidHCID 103332378-Acetyl-3-methoxy-benzo[c]chromen-6-one

Product 1

HCID 113244043-Methoxy-8-(2-methyl-[1,3]-dioxolan-2-yl)-benzo[c]chromen-6-oneYield 60.7%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

The compound from Step E (5.2 g, 19 mmol), ethylene glycol (4.4 g, 71 mmol) and a catalytic amount of p-toluenesulfonic acid (0.2 g) were dissolved in benzene (300 mL) and refluxed for 28 h. The solvent was removed and the crude product chromatographed on silica gel with hexane/ethyl acetate (2:1) to yield 3.6 g (60%) of the title compound. 1H-NMR (400 MHz, CDCl3) δH 1.75 (3H, s, CH3), 3.82 (2H, t, OCH2), 3.91 (3H, s, OCH3), 4.10 (2H, t, OCH2), 6.93 (1H, s, ArH), 6.98 (1H, d, ArH), 7.47 (3H, m, ArH), 8.04 (1H, s, ArH).

Workup

  1. temperaturerefluxed for 28 h
  2. customThe solvent was removed
  3. customthe crude product chromatographed on silica gel with hexane/ethyl acetate (2:1)

Sources & evidence

ORD record
ord-f55f89b8a0c14e0092ec97927e0a6b0e
Source dataset
uspto-grants-2003_10
Patent number
US06632835B2

Reaction notes

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