Methanol → 253324-72-0
Reaction equation
[F:1][C:2]1[CH:3]=[C:4]([CH:7]=[C:8]([F:10])[CH:9]=1)[CH:5]=[O:6].[CH:11](Br)(Br)Br.[OH-:15].[K+].[CH3:17][OH:18]>O.[Cl-].[Na+].O>[F:1][C:2]1[CH:3]=[C:4]([CH:5]([O:6][CH3:11])[C:17]([OH:18])=[O:15])[CH:7]=[C:8]([F:10])[CH:9]=1Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 2
Procedure
The title compound was prepared according to the general procedure in Reeve, et al, J.A.C.S., 83 :2755 (1961). A solution of 3,5-difluorobenzaldehyde (Aldrich) and bromoform (1.2 eq.) In methanol was cooled to −5° C. and treated dropwise with methanolic KOH. The reaction temperature was held below 6 C during the addition. The mixture was slowly warmed to room temperature and stirred overnight. The suspension was diluted with water and 50% saturated aqueous brine. The mixture was extracted with ether, and the aqueous layer was acidified to a pH around 3.5 and extracted with ether. The latter organic phase was dried over sodium sulfate, filtered and concentrated. The crude acid was purified via flash chromatography eluting with 1:4:95 acetic acid/methanol/methylene chloride to give a white solid. 1H NMR (300 MHz, CDCl3) δ 11.36 (1H, bs), 7.05 (1H, m), 6.81 (2H, tt, J=2.4, 8.8 Hz), 4.77 (1H, s), 3.47 (3H, s)/C9H8F2O3 (MW=202.17); mass spectroscopy—202.
Workup
- additionThe reaction temperature was held below 6 C during the addition
- extractionThe mixture was extracted with ether
- extractionextracted with ether
- dry with materialThe latter organic phase was dried over sodium sulfate
- filtrationfiltered
- concentrationconcentrated
- customThe crude acid was purified via flash chromatography
- washeluting with 1:4:95 acetic acid/methanol/methylene chloride
- customto give a white solid
Sources & evidence
- ORD record
- ord-549634ceea6d43b793b74dfc852e6d94
- Source dataset
- uspto-grants-2003_05
- Patent number
- US06569851B1
Reaction notes
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