Water → 1-(Benzo[d]oxazol-5-yl)cyclopropanecarboxylic acid

HRID 2242684Notes

Reaction equation

HRID 2242684 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]1

Participants

5

Reactant 3

HCID 962WaterHCID 6451240Aluminum(III) ChlorideHCID 591292661-Benzooxazol-5-yl-cyclopropanecarboxylic acid methyl ester

Product 1

HCID 591293171-(Benzo[d]oxazol-5-yl)cyclopropanecarboxylic acidYield 11%

Reagents, catalysts & solvents 1

HCID 6343EthanethiolSolvent

Procedure

To a solution of crude 1-benzooxazol-5-yl-cyclopropanecarboxylic acid methyl ester (2.9 g) in EtSH (30 mL) was added AlCl3 (5.3 g, 40.1 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/EtOAc 1:2) to give 1-(benzo[d]oxazol-5-yl)cyclopropanecarboxylic acid (280 mg, two steps: 11%). 1H NMR (DMSO 400 MHz) δ 12.25 (brs, 1H), 8.71 (s, 1H), 7.70-7.64 (m, 2H), 7.40 (dd, J=1.6, 8.4 Hz, 1H), 1.49-1.46 (m, 2H), 1.21-1.18 (m, 2H). MS (ESI) m/e (M+H+) 204.4.

Workup

  1. extractionThe resulting mixture was extracted with EtOAc (100 mL×3)
  2. dry with materialThe combined organic layers were dried over anhydrous Na2SO4
  3. customevaporated under vacuum
  4. customto give the crude product, which
  5. customwas purified by column chromatography on silica gel (petroleum ether/EtOAc 1:2)

Sources & evidence

ORD record
ord-e20cba5a5e9545f0b9545d4e13f6c447
Source dataset
uspto-grants-2010_03
Patent number
US07671221B2

Reaction notes

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