Hydrochloric Acid → 1522107-19-2

Temperature

-78 °C

To solution of 2-isobutylthiophene (743 mg, 5.30 mmol) in 9:1 tetrahydrofuran/hexamethylphosphoramide under argon at −78° C. was added n-butyllithium (2.3 mL, 2.5 M in hexanes) dropwise. The resulting solution was stirred for 20 minutes at −78° C. Bromine (0.35 mL, 6.89 mmol) was added dropwise as a solution in 1 mL anhydrous dichloromethane. The resulting mixture was stirred at −78° C. for 30 minutes before being poured, while cold, into 50 mL of 5% sodium bisulfite solution. 1 N hydrochloric acid (50 mL) was added and organics were extracted with ether (3×75 mL), washed with 0.1 N hydrochloric acid, water and brine (50 mL each), dried over magnesium sulfate, filtered and concentrated. The crude residue was subjected to chromatography on silica gel with gradient elution (0-10% ethyl acetate in hexanes) to give 2-bromo-5-isobutylthiophene as the major component of a mixture of two compounds. Used without further purification or characterization.

1. stirringThe resulting mixture was stirred at −78° C. for 30 minutes
2. additionbefore being poured
3. extractionorganics were extracted with ether (3×75 mL)
4. washwashed with 0.1 N hydrochloric acid, water and brine (50 mL each)
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated
8. washThe crude residue was subjected to chromatography on silica gel with gradient elution (0-10% ethyl acetate in hexanes)

ORD record

ord-f63e5a1a8254464094ba1f8ff9943bdf

Source dataset

uspto-grants-2016_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09315495B2