Triisopropyl borate → HCID 86627894, compound

HRID 1669411Notes

Reaction equation

[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([S:8]([O:11][C:12]2[CH:17]=[CH:16][C:15](Br)=[C:14]([O:19][CH2:20][O:21][CH3:22])[CH:13]=2)(=[O:10])=[O:9])=[CH:4][CH:3]=1.C1COCC1.C1(C)C=CC=CC=1.[B:35](OC(C)C)([O:40]C(C)C)[O:36]C(C)C.[Li]CCCC>CCOC(C)=O>[CH3:22][O:21][CH2:20][O:19][C:14]1[CH:13]=[C:12]([O:11][S:8]([C:5]2[CH:6]=[CH:7][C:2]([CH3:1])=[CH:3][CH:4]=2)(=[O:10])=[O:9])[CH:17]=[CH:16][C:15]=1[B:35]([OH:40])[OH:36]

Participants

Conditions

Temperature: -78 °C

Procedure

To a solution (0.30 M) of 4-bromo-3-(methoxymethoxy)phenyl 4-methylbenzenesulfonate in a mixture (1:3) of THF/toluene, triisopropyl borate was added and then the mixture cooled to −78° C. To the cold solution, n-BuLi (2.5 M in hexane; 1.5 eq) was added via syringe pump over 1.5 h. The mixture was stirred at −78° C. for a further 2 h and then left to warm to RT overnight. The mixture was diluted with EtOAc and washed with 1 N HCl, extracting the aqueous fraction a further two times with EtOAc. The combined organics were washed with sat. aq. NaHCO3 and brine, dried (Na2SO4), filtered and concentrated in vacuo to afford the product, that could be used directly as crude or purified by FC (PE/EtOAc 9/1) to afford the title compound (43%). 1H NMR (400 MHz, DMSO-d6, 300 K) δ 2.42 (s, 3H), 3.31 (s, 3H), 5.06 (s, 2H), 6.64-6.69 (m, 2H), 7.44-7.49 (m, 3H), 7.74 (d, J 8.3, 2H); (ES+) m/z 353 (M+H)+.

Workup

waitleft
temperatureto warm to RT overnight
washwashed with 1 N HCl
extractionextracting the aqueous fraction a further two times with EtOAc
washThe combined organics were washed with sat. aq. NaHCO3 and brine
dry with materialdried (Na2SO4)
filtrationfiltered
concentrationconcentrated in vacuo
customto afford the product, that
custompurified by FC (PE/EtOAc 9/1)

Sources & evidence

ORD record: ord-cab92e3717d64be5aa79de96ed977aac
Source dataset: uspto-grants-2011_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07989438B2

Reaction notes

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