Hexane → (2,3-dihydro-1H-inden-5-yl)boronic acid

HRID 1384393Notes

Reaction equation

C([Li])CCC.CCCCCC.Br[C:13]1[CH:14]=[C:15]2[C:19](=[CH:20][CH:21]=1)[CH2:18][CH2:17][CH2:16]2.C([O:24][B:25](OCC)[O:26]CC)C.[Cl-].[NH4+]>O1CCCC1>[CH2:18]1[C:19]2[C:15](=[CH:14][C:13]([B:25]([OH:26])[OH:24])=[CH:21][CH:20]=2)[CH2:16][CH2:17]1

Participants

Conditions

Temperature: -65 °C

Procedure

A solution of n-butyllithium 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-c4c8f7320b9b4d98a1ff2559a85641af
Source dataset: uspto-grants-2001_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06258843B1

Reaction notes

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