1-[4-(2,2-Diethoxyethoxy)phenyl]cyclopropanecarboxylic acid → 1-(Benzofuran-5-yl)cyclopropanecarboxylic acid

HRID 881083Notes

Reaction equation

C(O[CH:4](OCC)[CH2:5][O:6][C:7]1[CH:12]=[CH:11][C:10]([C:13]2([C:16]([OH:18])=[O:17])[CH2:15][CH2:14]2)=[CH:9][CH:8]=1)C>C1(C)C(C)=CC=CC=1>[O:6]1[C:7]2[CH:12]=[CH:11][C:10]([C:13]3([C:16]([OH:18])=[O:17])[CH2:15][CH2:14]3)=[CH:9][C:8]=2[CH:4]=[CH:5]1

Participants

Conditions

Temperature: 140 °C

Procedure

To a suspension of crude 1-[4-(2,2-diethoxy-ethoxy)-phenyl]-cyclopropanecarboxylic acid (20 g, ˜65 mmol) in xylene (100 mL) was added PPA (22.2 g, 64.9 mmol) at room temperature. The mixture was heated at reflux (140° C.) for 1 hour before it was cooled to room temperature and decanted from the PPA. The solvent was evaporated under vacuum to obtain the crude product, which was purified by preparative HPLC to provide 1-(benzofuran-5-yl)cyclopropanecarboxylic acid (1.5 g, 5%). 1H NMR (400 MHz, DMSO-d6) δ 12.25 (br s, 1 H), 7.95 (d, J=2.8 Hz, 1 H), 7.56 (d, J=2.0 Hz, 1 H), 7.47 (d, J=11.6 Hz, 1 H), 7.25 (dd, J=2.4, 11.2 Hz, 1 H), 6.89 (d, J=1.6 Hz, 1 H), 1.47-1.44 (m, 2 H), 1.17-1.14 (m, 2 H).

Workup

additionwas added PPA (22.2 g, 64.9 mmol) at room temperature
temperatureThe mixture was heated
temperaturewas cooled to room temperature
customdecanted from the PPA
customThe solvent was evaporated under vacuum
customto obtain the crude product, which
customwas purified by preparative HPLC

Sources & evidence

ORD record: ord-62f81528405343b7988bb7a80d35e2e3
Source dataset: uspto-grants-2015_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08993600B2

Reaction notes

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