Hexane → 4-Borono-3-methylbenzoic acid
Reaction equation
Br[C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[CH3:11].C([Li])CCC.CCCCCC.[B:23](OC(C)C)([O:28]C(C)C)[O:24]C(C)C>C1COCC1.O>[B:23]([C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[CH3:11])([OH:28])[OH:24]Participants
7
Conditions
- Temperature
- -78 °C
Procedure
A stirred solution of 4-bromo-3-methylbenzoic acid (5.0 g, 0.02 mole) in dry THF (250 ml) at -78° C. under argon was treated with 1.6M n-butyllithium in hexane (36.3 ml, 0.05 mole). The mixture changed from a clear solution to an orange suspension. This was stirred at -78° C. for 0.25 h, then treated with triisopropyl borate (13.4 ml, 0.05 mole) and stirred at -78° C. for a further 1 h. The mixture was allowed to warm to room temp. and stir for 19 h, then treated with water (25 ml) and concentrated in vacuo. The residue was chromatographed on silica gel eluting with 10% methanol/dichloromethane to afford the title compound as a white solid (2.63 g, 67%).
Workup
- stirringstirred at -78° C. for a further 1 h
- temperatureto warm to room temp.
- stirringstir for 19 h
- concentrationconcentrated in vacuo
- customThe residue was chromatographed on silica gel eluting with 10% methanol/dichloromethane
Sources & evidence
- ORD record
- ord-c0a83057945c473bb1fa9471038772e5
- Source dataset
- uspto-grants-1999_10
- Patent number
- US05972951
Reaction notes
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