反应详情

A stirred suspension of 4-(4′-cyano-biphenyl-4-yl)-4-oxo-butyric acid (0.7908 g, 0.002831 mol), hydroxylamine hydrochloride (0.2038 g, 0.00293 mol), sodium carbonate (0.3158 g, 0.00298 mol) in absolute ethanol (17 mL) was refluxed under nitrogen for 12 hours and allowed to cool. The mixture was allowed to stand for 2.5 days for convenience. Volatiles were rotary evaporated, and the residue was partitioned between dichloromethane-tetrahydrofuran (50/50 v/v) and 0.05 M aqueous hydrochloric acid (60 mL). The aqueous layer was extracted with additional organics. The extracts were combined, dried (Na2SO4) and rotary evaporated. The residue was dissolved/suspended in dichloromethane and chromatographed on silica gel (165 g, 230-400 mesh), eluting with dichloromethane-methanol (25:1, 30×125 mL; 15:1, 5×125 mL) to give 0.413 g of 4-(4′-cyano-biphenyl-4-yl)-4-hydroxyimino-butyric acid as an off-white solid; mp 157-159° C.

1. temperaturewas refluxed under nitrogen for 12 hours
2. temperatureto cool
3. customthe residue was partitioned between dichloromethane-tetrahydrofuran (50/50 v/v) and 0.05 M aqueous hydrochloric acid (60 mL)
4. extractionThe aqueous layer was extracted with additional organics
5. dry with materialdried (Na2SO4) and rotary evaporated
6. customchromatographed on silica gel (165 g, 230-400 mesh)
7. washeluting with dichloromethane-methanol (25:1, 30×125 mL; 15:1, 5×125 mL)