1,3-Dibromopropane → 2-[4-(3-Bromopropoxy)phenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

HRID 657527Notes

Reaction equation

[CH3:1][C:2]1([CH3:16])[C:6]([CH3:8])([CH3:7])[O:5][B:4]([C:9]2[CH:14]=[CH:13][C:12]([OH:15])=[CH:11][CH:10]=2)[O:3]1.C([O-])([O-])=O.[K+].[K+].[Br:23][CH2:24][CH2:25][CH2:26]Br>CC#N>[Br:23][CH2:24][CH2:25][CH2:26][O:15][C:12]1[CH:13]=[CH:14][C:9]([B:4]2[O:3][C:2]([CH3:16])([CH3:1])[C:6]([CH3:7])([CH3:8])[O:5]2)=[CH:10][CH:11]=1

Participants

Conditions

Temperature: 70 °C

Procedure

4-(4,4,5,5-Tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenol (CAS #269409-70-3) (10.5 g, 47 mmol) was dissolved in dry CH3CN (200 mL) and dry, pulverized K2CO3 (10.4 g, 75 mmol) was introduced. 1,3-dibromopropane (38.1 mL, 375 mmol) was added dropwise, and the reaction mixture was heated at 70° C. for 7 h under a nitrogen atmosphere. The cooled reaction mixture was filtered and the filtrate was evaporated to an oily residue, which was applied to a column of silica gel. Elution initially with hexanes, gradually increasing polarity to a mixture of hexanes/ethyl acetate (25:1, 20:1 and 10:1) as eluent, provided the title compound (13.93 g, 86%) which crystallized on standing to a white solid, m.p. 62-65° C.

Workup

customdry
additionwas introduced
customThe cooled reaction mixture
filtrationwas filtered
customthe filtrate was evaporated to an oily residue, which
washElution initially with hexanes
temperaturegradually increasing polarity
additionto a mixture of hexanes/ethyl acetate (25:1, 20:1 and 10:1) as eluent

Sources & evidence

ORD record: ord-4c7e820adb7641b0bc25cf47346d48be
Source dataset: uspto-grants-2011_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08076331B2

Reaction notes

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