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

HRID 503297Notes

Reaction equation

HRID 503297 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-81fd70f61edf4459a92906dc965c1b32
Source dataset
uspto-grants-2010_08
Patent number
US07776905B2

Reaction notes

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