N-bromobutanimide → 2-(5-bromothiophen-2-yl)ethanol

Temperature

-20 °C

2-(2-thienyl)ethanol (Aldrich, 5.0 g, 39 mmol) was diluted in toluene (50 mL) and cooled to −20° C. using an ice/NaCl bath. NBS (6.95 g, 39 mmol, 1 eq) was added portionwise over 15 minutes and the mixture was stirred at rt overnight. After quenching with 10% aq potassium hydroxide (20 mL), the layers were separated and the aqueous layer was extracted twice with dichloromethane (50 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated. Purification by Isco Combiflash, eluting with 0-80% ethyl acetate in hexanes (120 g column), afforded the desired as a slightly yellow oil (6.72 g, 83%).

1. customAfter quenching with 10% aq potassium hydroxide (20 mL)
2. customthe layers were separated
3. extractionthe aqueous layer was extracted twice with dichloromethane (50 mL)
4. dry with materialThe combined organic layers were dried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. customPurification by Isco Combiflash
8. washeluting with 0-80% ethyl acetate in hexanes (120 g column)
9. customafforded the

ORD record

ord-3af207063f4c46249b374db00a80894e

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08372875B2