Hexane → (2,3-dihydro-1H-inden-5-yl)boronic acid
Reaction equation
CCCCCC.Br[C:8]1[CH:9]=[C:10]2[C:14](=[CH:15][CH:16]=1)[CH2:13][CH2:12][CH2:11]2.C([O:19][B:20](OCC)[O:21]CC)C.[Cl-].[NH4+]>O1CCCC1>[CH2:13]1[C:14]2[C:10](=[CH:9][C:8]([B:20]([OH:21])[OH:19])=[CH:16][CH:15]=2)[CH2:11][CH2:12]1Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -65 °C
Procedure
A solution of n-butylithium in hexane (13.2 mL of 1.6 M, 21 mmol) is added to a stirred solution of 5-bromo-indane (1.06 g 4 mmol) in dry tetrahydrofuran (30 mL) at −75° C. under an argon atmosphere. The mixture is stirred for 30 min at −65° C., then treated with triethylborate (3.07 g, 21 mmol) and stirred for 60 min at −50° C. The resulting mixture is allowed to warm to 0° C. and then treated with a saturated aqueous solution of ammonium chloride (60 mL) and extracted with ethyl acetate (2×80 mL). The combined extracts are dried (Na2SO4), filtered and the solvent is evaporated off under reduced pressure to yield the crude product which is purified by chromatography (silica gel, 50% ethyl acetate in hexaen) and recrystallised from ethyl acetate-hexane to give indan-5-boronic acid as a colourless crystalline solid.
Workup
- stirringstirred for 60 min at −50° C
- temperatureto warm to 0° C.
- extractionextracted with ethyl acetate (2×80 mL)
- dry with materialThe combined extracts are dried (Na2SO4)
- filtrationfiltered
- customthe solvent is evaporated off under reduced pressure
- customto yield the crude product which
- customis purified by chromatography (silica gel, 50% ethyl acetate in hexaen)
- customrecrystallised from ethyl acetate-hexane
Sources & evidence
- ORD record
- ord-830f1fb430ab45449374a0996acd9c03
- Source dataset
- uspto-grants-2001_09
- Patent number
- US06288092B1
Reaction notes
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