Ethanol → rac-(1R,2R)-2-(4-bromophenyl)cyclopropane-1-carboxylic acid
Reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C@@H:8]2[CH2:10][C@H:9]2NS(C(C)C)(=O)=O)=[CH:4][CH:3]=1.[OH-:18].[Na+].C[CH2:21][OH:22]>>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([C@@H:8]2[CH2:10][C@H:9]2[C:21]([OH:22])=[O:18])=[CH:6][CH:7]=1Participants
4
Procedure
To a solution of racemic trans-ethyl 2-(4-bromophenyl)cyclopropanecarboxylate (Intermediate 2) (4.97 g, 18.47 mmol) in 76.72 mL of EtOH was added dropwise 49.08 mL of 2N NaOH and the mixture was stirred at room temperature for 1 h. The solution was then concentrated in vacuo, 20 mL of water were added and the aqueous phase washed with 2×20 mL Et2O. The aqueous phase was then acidified with 2M HCl to pH 3 (approx.) and extracted with 3×100 mL Et2O. The collected organic phases were dried over Na2SO4, filtered and concentrated in vacuo to get 4.43 g of the title compound as a white solid, which was used in the next step without further purification.
Workup
- concentrationThe solution was then concentrated in vacuo, 20 mL of water
- additionwere added
- washthe aqueous phase washed with 2×20 mL Et2O
- extractionextracted with 3×100 mL Et2O
- dry with materialThe collected organic phases were dried over Na2SO4
- filtrationfiltered
- concentrationconcentrated in vacuo
Sources & evidence
- ORD record
- ord-c92727027f814b09b38906e2786227bb
- Source dataset
- uspto-grants-2010_09
- Patent number
- US07790758B2
Reaction notes
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