Water → 1-(Benzo[d]oxazol-5-yl)cyclopropanecarboxylic acid
Reaction equation
C[O:2][C:3]([C:5]1([C:8]2[CH:9]=[CH:10][C:11]3[O:15][CH:14]=[N:13][C:12]=3[CH:16]=2)[CH2:7][CH2:6]1)=[O:4].[Al+3].[Cl-].[Cl-].[Cl-].O>CCS>[O:15]1[C:11]2[CH:10]=[CH:9][C:8]([C:5]3([C:3]([OH:4])=[O:2])[CH2:7][CH2:6]3)=[CH:16][C:12]=2[N:13]=[CH:14]1Participants
Procedure
To a solution of 1-benzooxazol-5-yl-cyclopropanecarboxylic acid methyl ester (2.9 g) in EtSH (30 mL) was added AlCl3 (5.3 g, 40 mmol) in portions at 0° C. The reaction mixture was stirred for 18 hours at room temperature. Water (20 mL) was added dropwise at 0° C. The resulting mixture was extracted with EtOAc (100 mL×3). The combined organic layers were dried over anhydrous Na2SO4 and evaporated under vacuum to give the crude product, which was purified by column chromatography on silica gel (petroleum ether/ethyl acetate 1:2) to give 1-(benzo[d]oxazol-5-yl)cyclopropanecarboxylic acid (280 mg, 11% over two steps). 1H NMR (DMSO, 400 MHz) δ 12.25 (brs, 1 H), 8.71 (s, 1 H), 7.70-7.64 (m, 2 H), 7.40 (dd, J=1.6, 8.4 Hz, 1 H), 1.49-1.46 (m, 2 H), 1.21-1.18 (m, 2 H). MS (ESI) m/e (M+H+) 204.4.
Workup
- extractionThe resulting mixture was extracted with EtOAc (100 mL×3)
- dry with materialThe combined organic layers were dried over anhydrous Na2SO4
- customevaporated under vacuum
- customto give the crude product, which
- customwas purified by column chromatography on silica gel (petroleum ether/ethyl acetate 1:2)
Sources & evidence
- ORD record
- ord-8c5cc672118c4ebfa455403735e1d917
- Source dataset
- uspto-grants-2013_04
- Patent number
- US08415387B2
Reaction notes
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