Hydrochloric Acid → 2-(1,3-Dihydro-1-hydroxy-2,1-benzoxaborol-6-yloxy)pentan-3-one

HRID 529203Notes

Reaction equation

[OH:1][C:2]1[CH:11]=[CH:10][C:5]2[CH2:6][O:7][B:8]([OH:9])[C:4]=2[CH:3]=1.[H-].[Na+].Br[CH:15]([C:17](=[O:20])[CH2:18][CH3:19])[CH3:16].Cl>CN(C=O)C>[OH:9][B:8]1[C:4]2[CH:3]=[C:2]([O:1][CH:15]([C:17](=[O:20])[CH2:18][CH3:19])[CH3:16])[CH:11]=[CH:10][C:5]=2[CH2:6][O:7]1

Participants

Conditions

Temperature: 0 °C

Procedure

H181 (150 mg, 1.0 mmol) was dissolved in DMF (6.0 mL) and cooled to 0° C. with ice bath. To this solution under nitrogen were added in sequence NaH (60% in mineral oil, 160 mg, 4.0 mmol) and 2-bromopentan-3-one (660.12 mg, 4.0 mmol). The reaction mixture was stirred for 1 d then treated with 1.0 M HCl (10.0 mL). After extraction with ethyl acetate, the organic phase was washed with water and brine, and dried over anhydrous Na2SO4. The residue after rotary evaporation was purified by column chromatography over silica gel to give the title compound (88.9 mg, 38% yield). 1H NMR (400 MHz, CDCl3): δ 7.21 (d, J=8.1 Hz, 1H), 7.06 (d, J=2.4 Hz, 1H), 6.98 (dd, J=8.4 & 2.7 Hz, 1H), 5.00 (s, 2H), 4.67 (q, J=6.8 Hz, 1H), 2.73-2.61 (m, 1H), 2.49-2.39 (m, 1H), 1.47 (d, J=6.8 Hz, 3H) and 0.99 (t, J=7.2 Hz, 3H) ppm; Mp: 72-74° C.

Workup

extractionAfter extraction with ethyl acetate
washthe organic phase was washed with water and brine
dry with materialdried over anhydrous Na2SO4
customThe residue after rotary evaporation
customwas purified by column chromatography over silica gel

Sources & evidence

ORD record: ord-fb2b4b9d1f2843ec811d8d8cef4d0a2a
Source dataset: uspto-grants-2016_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09346834B2

Reaction notes

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