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

HRID 1964256Notes

Reaction equation

HRID 1964256 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, 3 H), 3.62 (s, 3 H), 2.64-2.58 (m, 4 H), 1.89-1.78 (m, 2 H), 1.56-1.54 (m, 2 H), 1.53-1.12(m, 2 H).

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-a1cc7a20979744c08ee3c79a6c7d8dd2
Source dataset
uspto-grants-2013_04
Patent number
US08415387B2

Reaction notes

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