4-Methoxy-2,2,6,6-tetramethylpiperidinyl-1-oxy → 1-(5-Chloro-6-fluoro-1H-benzoimidazol-2-yl-)2,2,2-trifluoro-ethanone

1-(5-Chloro-6-fluoro-1H-benzoimidazol-2-yl)-2,2,2-trifluoro-ethanol (0.34 g; 1.3 mmoles), 4-methoxy-2,2,6,6-tetramethyl-1-piperdinyloxy free radical (4-methoxy-TEMPO free radical; 6.1 mg; 0.03 mmoles) and potassium bromide (KBr; 18 mg; 0.15 mmoles) were dissolved in THF (3.5 mL). The reaction mixture was stirred while cooled to −10° C., after 10 min. a sodium hypochlorite solution (bleach; 10-13% aqueous; 3.0 mL; 5.04 mmoles) was added and allowed to stir for 15 min., then warmed to room temperature and stirred for 15 min. The reaction mixture was diluted with water (20 mL) and ethyl acetate (30 mL), the layers were separated and the aqueous layer was extracted with ethyl acetate (3×30 mL). The extracts were combined and washed with water (30 mL) and brine (40 mL), then dried over Na2SO4. The filtrate was concentrated in vacuo and purified by column chromatography (SiO2; 100% diethyl ether) to yield the title compound as a light yellow solid.

1. additionwas added
2. stirringto stir for 15 min.
3. stirringstirred for 15 min
4. customthe layers were separated
5. extractionthe aqueous layer was extracted with ethyl acetate (3×30 mL)
6. washwashed with water (30 mL) and brine (40 mL)
7. dry with materialdried over Na2SO4
8. concentrationThe filtrate was concentrated in vacuo
9. custompurified by column chromatography (SiO2; 100% diethyl ether)

ORD record

ord-e8e95e62f27c461e9926e8b22edbb807

Source dataset

uspto-grants-2009_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07566733B2