Hydrochloric Acid → 6-Ethoxy-1,3-dihydro-1-hydroxy-2,1-benzoxaborole

Temperature

0 °C

H181 (110 mg, 0.73 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, 117 mg, 2.93 mmol) and bromoethane (0.22 mL, 2.93 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 (85 mg, 65% yield). 1H NMR (300 MHz, DMSO-d6): δ 9.13 (s, 1H), 7.29 (d, J=8.1 Hz, 1H), 7.20 (d, J=2.4 Hz, 1H), 7.03 (dd, J=8.1 & 2.4 Hz, 1H), 4.91 (s, 2H), 4.02 (q, J=7.0 Hz, 2H) and 1.33 (t, J=7.2 Hz, 3H) ppm; Mp: 80-82° C.

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

ORD record

ord-29eda886421849d6b3341170d681ae7e

Source dataset

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09346834B2