Cyanogen Bromide → 5-[(4-Fluorophenyl)methyl]-1,3,4-oxadiazol-2-amine

Participants

Reaction Conditions

Reaction Steps

Solid BrCN 13.37 g (130 mmol, 1.1 eq.) was added in one portion into ice-cooled slurry of (4-Fluoro-phenyl)-acetic acid hydrazide (19.85 g, 118 mmol) and KHCO3 14.77 g (147.5 mmol, 1.25 eq.) in MeOH (150 mL) in a 1L flask. (Followed by MeOH 10 mL to wash the funnel). The mixture was stirred on ice bath at 0-5° C. for 2 hours in a loose-capped flask, then the bath allowed to melt gradually and then the mixture was stirred at 5 to 20° C. overnight (17 hrs). The reaction mixture was diluted with water (200 mL), stirred for 1 hour in an open flask, then cooled on ice bath. The precipitate was collected by filtration, washed with water and dried on highvac. [1st fraction]The supernatants were concentrated on rotavap form warm (40° C.) water bath to remove all MeOH and some water. The obtained slurry was cooled to room temperature, the precipitate was collected by filtration, washed with water and dried on highvac. [2nd fraction]. Combined yield: 20.836 g (91.5%) of a white crystalline solid.

Provenance & Evidence