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

Temperature

2.5 °C

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.

1. washto wash the funnel)
2. stirringthe mixture was stirred at 5 to 20° C. overnight (17 hrs)
3. additionThe reaction mixture was diluted with water (200 mL)
4. stirringstirred for 1 hour in an open flask
5. temperaturecooled on ice bath
6. filtrationThe precipitate was collected by filtration
7. washwashed with water
8. customdried on highvac
9. concentration[1st fraction]The supernatants were concentrated on rotavap form
10. temperaturewarm (40° C.) water bath
11. customto remove all MeOH
12. temperatureThe obtained slurry was cooled to room temperature
13. filtrationthe precipitate was collected by filtration
14. washwashed with water
15. customdried on highvac

ORD record

ord-090a6af3306d4c7c9c294f3515cdf504

Source dataset

uspto-grants-2006_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07037909B2