Lithium hydroxide, monohydrate → 1-(2-Oxo-2,3-dihydro-1,3-benzoxazol-5-YL)cyclopropane-1-carboxylic acid

HRID 1908325Notes

Reaction equation

C[O:2][C:3]([C:5]1([C:8]2[CH:9]=[CH:10][C:11]3[O:15][C:14](=[O:16])[NH:13][C:12]=3[CH:17]=2)[CH2:7][CH2:6]1)=[O:4].O[Li].O>CO.O>[O:16]=[C:14]1[NH:13][C:12]2[CH:17]=[C:8]([C:5]3([C:3]([OH:4])=[O:2])[CH2:7][CH2:6]3)[CH:9]=[CH:10][C:11]=2[O:15]1

Participants

Conditions

Temperature: 50 °C

Procedure

To a solution of 1-(2-oxo-2,3-dihydro-benzooxazol-5-yl)-cyclopropanecarboxylic acid methyl ester (1.9 g, 8.1 mmol) in MeOH (20 mL) and water (2 mL) was added LiOH.H2O (1.7 g, 41 mmol) in portions at room temperature. The reaction mixture was stirred for 20 hours at 50° C. MeOH was removed by evaporation under vacuum before water (100 mL) and EtOAc (50 mL) were added. The aqueous layer was separated, acidified with HCl (3 mol/L) and extracted with EtOAc (100 mL×3). The combined organic layers were dried over anhydrous Na2SO4 and evaporated under vacuum to give 1-(2-oxo-2,3-dihydrobenzo[d]oxazol-5-yl)cyclopropanecarboxylic acid (1.5 g, 84%). 1H NMR (DMSO, 400 MHz) δ 12.32 (brs, 1H), 11.59 (brs, 1H), 7.16 (d, J=8.4 Hz, 1H), 7.00 (d, J=8.0 Hz, 1H), 1.44-1.41 (m, 2H), 1.13-1.10 (m, 2H). MS (ESI) m/e (M+H+) 218.1.

Workup

customMeOH was removed by evaporation under vacuum before water (100 mL) and EtOAc (50 mL)
additionwere added
customThe aqueous layer was separated
extractionextracted with EtOAc (100 mL×3)
dry with materialThe combined organic layers were dried over anhydrous Na2SO4
customevaporated under vacuum

Sources & evidence

ORD record: ord-0485aeed8779472bb91b2c0a4fa90c84
Source dataset: uspto-grants-2013_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08598181B2

Reaction notes

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