Hydrochloric Acid → 3-(1-Methylcyclohexyl)-4-methoxyphenyl boronic acid

Temperature

-75 °C

To a mixture of 2-(1-methylcyclohexyl)-4-bromoanisole (13.66 g, 0.0482 mol) in THF (121 mL) cooled to −75° C. under an atmosphere of argon was added n-BuLi (33.2 mL, 1.6 M, 0.053 mol) dropwise maintaining a temperature below −70° C. The resulting suspension was stirred for 30 minutes and triisopropylborate (34.2 mL, 27.87 g, 0.148 mol) was added dropwise. The mixture was allowed to warm to RT overnight. The resulting mixture was cooled to 0° C. and 1.0 N HCl (150 mL) was slowly added. After warming to RT the mixture was diluted with ether and the layers separated, the aqueous layer was extracted ether (3×) and the organic layers combined. The resulting organic layer was washed with water, brine and dried (Mg2SO4). The mixture was filtered, evaporated and the resulting yellow oil was purified on silica gel (eluent: CH2Cl2:MeOH, 100 to 92:2) to afford 3-(1-methylcyclohexyl)-4-methoxyphenyl boronic acid (7.72 g, 64%) as a white solid. 1H NMR (300 MHz; DMSO-d6): δ 120 (s, 3H), 1.40–1.85 (m, 8H), 2.00–2.10 (m, 2H), 3.75 (s, 3H), 6.90 (d, J=8.4 Hz, 1H), 7.60 (d, J=8.4 Hz, 1H), 7.66 (brs, 1H), 7.81 (s, 2H).

1. temperaturedropwise maintaining a temperature below −70° C
2. temperatureto warm to RT overnight
3. temperatureThe resulting mixture was cooled to 0° C.
4. temperatureAfter warming to RT the mixture
5. customthe layers separated
6. extractionthe aqueous layer was extracted ether (3×)
7. washThe resulting organic layer was washed with water, brine
8. dry with materialdried (Mg2SO4)
9. filtrationThe mixture was filtered
10. customevaporated
11. customthe resulting yellow oil was purified on silica gel (eluent: CH2Cl2:MeOH, 100 to 92:2)

ORD record

ord-9b246636201f45418b1b1b6a80748f0b

Source dataset

uspto-grants-2006_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07153875B2