Diisopropylamine → HCID 87356133, compound

Temperature

-78 °C

A solution of 2-bromothiophene (0.5 g, 3.00 mmol) in dry THF (5 mL) was cooled to −78° C. and freshly prepared lithium diisopropylamide (prepared from diisopropyl amine (0.5 mL, 3.60 mmol) and nBuLi (2.3 mL, 3.60 mmol, 1.6M in THF) was added dropwise. The reaction mixture was stirred at −78° C. for 1 h. Ethyl difluoro acetate (409 mg, 3.30 mmol) was added dropwise at −78° C. and the reaction mixture was stirred for 1 h, then slowly warmed up to room temperature and quenched with saturated NH4Cl solution. The organic product was extracted with EtOAc and dried over anhydrous sodium sulfate. The solvent was concentrated under reduced pressure to get 1-(5-bromothiophen-2-yl)-2,2-difluoroethanone (500 mg, yield 69%). 1H NMR (400 MHz, CDCl3) δ 7.77-7.75 (m, 1H), 7.21-7.20 (d, J=4.1 Hz, 1H), 6.27-6.00 (m, 1H).

1. additionwas added dropwise
2. stirringthe reaction mixture was stirred for 1 h
3. temperatureslowly warmed up to room temperature
4. customquenched with saturated NH4Cl solution
5. extractionThe organic product was extracted with EtOAc
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationThe solvent was concentrated under reduced pressure

ORD record

ord-02a1d62a035c4e8da234176f1fae4034

Source dataset

uspto-grants-2014_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08901156B2