Tetrabutylammonium Fluoride → 4-((1R,2S)-1-(5-(4-bromophenyl)-1,3,4-oxadiazol-2-yl)-2-hydroxypropylamino)-2-chloro-3-methylbenzonitrile

Temperature

-20 °C

To a solution of 4-((1R,2S)-1-(5-(4-bromophenyl)-1,3,4-oxadiazol-2-yl)-2-(tert-butyldimethylsilyloxy)propylamino)-2-chloro-3-methylbenzonitrile (1.63 g, 2.9 mmol) in THF (60 mL) was added TBAF (3.2 mL, 3.2 mmol, 1 M solution in THF) at −50° C. After addition, the reaction mixture was allowed to warm to −20° C. gradually (about 1 h), then quenched by adding saturated aqueous NH4Cl solution (20 mL) and extracted with EtOAc. The EtOAc extracts were washed with water, brine, dried over Na2SO4 and filtered. Concentration provided a residue, which was purified by flash chromatography over silica gel to provide the title compound 4-((1R,2S)-1-(5-(4-bromophenyl)-1,3,4-oxadiazol-2-yl)-2-hydroxypropylamino)-2-chloro-3-methylbenzonitrile (1.10 g, 85%). 1H NMR (400 MHz, CDCl3, δ in ppm) 7.79 (d, J=8.4 Hz, 2H), 7.61 (d, J=8.4 Hz, 2H), 7.40 (d, J=8.8 Hz, 1H), 6.63 (d, J=8.8 Hz, 1H), 5.23 (d, J=8.6 Hz, 1H), 4.72 (dd, J=2.5, 8.6 Hz, 1H), 4.62 (m, 1H), 3.01 (d, J=3.5 Hz, 1H), 2.34 (s, 3H), 1.42 (d, J=6.3 Hz, 3H).

1. additionAfter addition
2. customquenched
3. additionby adding saturated aqueous NH4Cl solution (20 mL)
4. extractionextracted with EtOAc
5. washThe EtOAc extracts were washed with water, brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationConcentration
9. customprovided a residue, which
10. customwas purified by flash chromatography over silica gel

ORD record

ord-df1c624e054041e3bb7b3c0795194e38

Source dataset

uspto-grants-2013_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08455525B2