Hydrochloric Acid → 2-Benzyloxy-5-trifluoromethylphenylboronic acid

A solution of 4-benzyloxy-3-bromobenzotrifluoride (4.48 g, 13.54 mmol) in tetrahydrofuran (100 ml) was cooled to −100° C. (diethyl ether/liquid nitrogen) with stirring under nitrogen. 1.6 M n-butyllithium in hexanes (9.3 ml, 14.89 mmol) was added over 20 mins. at −100° C. and the mixture warmed to −78° C. (acetone/Drikold) and stirred for 1 h. Triisopropylborate (7.64 g, 9.38 ml, 40.66 mmol) was added dropwise at −78° C. and the reaction stirred and allowed to warm to room temperature over 1.5 h. 1M Hydrochloric acid (100 ml) was added and the mixture stirred vigorously for 1 h. The layers were separated and the aqueous layer extracted with diethyl ether (50 ml). The combined organic phases were washed with water, dried (MgSO4) and the solvent removed in vacuo. The yellow waxy solid was flash chromatographed (silica gel, 4-20% EtOAc-isohexane) and the product triturated with hexane. The white solid was filtered and dried in vacuo to give the title compound (1.53 g, 38%).

1. stirringstirred for 1 h
2. stirringthe reaction stirred
3. stirringthe mixture stirred vigorously for 1 h
4. customThe layers were separated
5. extractionthe aqueous layer extracted with diethyl ether (50 ml)
6. washThe combined organic phases were washed with water
7. dry with materialdried (MgSO4)
8. customthe solvent removed in vacuo
9. customchromatographed (silica gel, 4-20% EtOAc-isohexane)
10. customthe product triturated with hexane
11. filtrationThe white solid was filtered
12. customdried in vacuo

ORDレコード

ord-bd0fd85a63164f8c8d8aa1b007100bc2

出典データセット

uspto-grants-2008_11

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US07446222B2