Tetrahydrofuran → 2-(2-(Ethylthio)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Temperature

-70 °C

A mixture of 14.1 g of 1-bromo-2-ethylsulfanylbenzene and 65 mL of THF was cooled to −70° C., and 44.7 mL of n-butyllithium (1.63 M hexane solvent) was added to the mixture at a rate so as to maintain an internal temperature of −60° C. or lower, and the mixture was stirred at −50° C. for 30 minutes. A mixture of 14 g of isopropoxyboronic acid pinacol ester and 5 mL of THF was added to the mixture at a rate so as to maintain an internal temperature of −60° C. or lower, and the mixture was heated to room temperature. Water was poured to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with water, then dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting residue was applied to a silica gel column chromatography to obtain 7.9 g of 2-ethylsulfanylphenylboronic acid pinacol ester.

1. temperatureto maintain an internal temperature of −60° C.
2. additionwas added to the mixture at a rate so as
3. temperatureto maintain an internal temperature of −60° C.
4. temperaturelower, and the mixture was heated to room temperature
5. extractionthe mixture was extracted with ethyl acetate
6. washThe organic layer was washed with water
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationconcentrated under reduced pressure

ORD record

ord-b208a98f8f964c518f29a5c5e2d45938

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09271500B2