Hydrogen Bromide → 2-Bromo-1-(5-ethylthiophen-3-yl)ethanone

Temperature

0 °C

5-Ethylthiophene-3-carbonyl chloride (224 mg, 1.28 mmol) was dissolved in dry CH3CN (10 ml) and cooled at 0° C., under nitrogen atmosphere. (Diazomethyl)-trimethylsilane (1.92 ml, 3.85 mmol, 2M in hexane) was slowly added, and the resulting reaction was stirred at room temperature for 18 hours. Then the reaction was cooled at 0° C. and 48% HBr was added dropwise. The reaction was stirred at 0° C. for 2 hours. Smashed ice was added to the mixture, and then sodium bicarbonate was added until pH is about 7. The solution was extracted with EtOAc, and the organic layer was separated, dried over sodium sulfate, filtered and evaporated under reduced pressure. The crude was purified by flash chromatography (Petroleum ether/EtOAc=9/1) to obtain 2-bromo-1-(5-ethylthiophen-3-yl)ethanone (97 mg, 32.4% yield).

1. customthe resulting reaction
2. temperatureThen the reaction was cooled at 0° C.
3. stirringThe reaction was stirred at 0° C. for 2 hours
4. additionSmashed ice was added to the mixture
5. extractionThe solution was extracted with EtOAc
6. customthe organic layer was separated
7. dry with materialdried over sodium sulfate
8. filtrationfiltered
9. customevaporated under reduced pressure
10. customThe crude was purified by flash chromatography (Petroleum ether/EtOAc=9/1)

ORD record

ord-b1e6217d49484f49b82a2c67aeb0d503

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08492548B2