p-Toluenesulfonic acid → Methyl 1-(spiro[benzo[d][1,3]dioxole-2,1'-cyclobutane]-5-yl)cyclopropanecarboxylate

HRID 1991670Notes

Reaction equation

HRID 1991670 reaction equation
[CH3:1][O:2][C:3]([C:5]1([C:8]2[CH:13]=[CH:12][C:11]([OH:14])=[C:10]([OH:15])[CH:9]=2)[CH2:7][CH2:6]1)=[O:4].CC1C=[CH:19][C:20](S(O)(=O)=O)=[CH:21][CH:22]=1.C1(=O)CCC1>C1(C)C=CC=CC=1>[C:19]12([O:14][C:11]3[CH:12]=[CH:13][C:8]([C:5]4([C:3]([O:2][CH3:1])=[O:4])[CH2:7][CH2:6]4)=[CH:9][C:10]=3[O:15]1)[CH2:20][CH2:21][CH2:22]2

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 14496CyclobutanoneHCID 59129280Methyl 1-(3,4-dihydroxyphenyl)cyclopropanecarboxylate

Product 1

HCID 59129386Methyl 1-(spiro[benzo[d][1,3]dioxole-2,1'-cyclobutane]-5-yl)cyclopropanecarboxylateYield 461%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a solution of 1-(3,4-dihydroxy-phenyl)-cyclopropanecarboxylic methyl ester (1.0 g, 4.8 mmol) in toluene (30 mL) was added TsOH (0.10 g, 0.50 mmol) and cyclobutanone (0.70 g, 10 mmol). The reaction mixture was heated at reflux for 2 h before being concentrated under vacuum. The residue was purified by chromatography on silica gel (petroleum ether/ethyl acetate 15:1) to give methyl 1-(spiro[benzo[d][1,3]dioxole-2,1′-cyclobutane]-5-yl)cyclopropanecarboxylate (0.6 g, 50%). 1H NMR (CDCl3 300 MHz) δ 6.78-6.65 (m, 3H), 3.62 (s, 3H), 2.64-2.58 (m, 4H), 1.89-1.78 (m, 2H), 1.56-1.54 (m, 2H), 1.53-1.12 (m, 2H).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureat reflux for 2 h
  3. concentrationbefore being concentrated under vacuum
  4. customThe residue was purified by chromatography on silica gel (petroleum ether/ethyl acetate 15:1)

Sources & evidence

ORD record
ord-0d866784598d47a18df084d7a8307b2e
Source dataset
uspto-grants-2010_01
Patent number
US07645789B2

Reaction notes

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