Acetic Anhydride → 3-(4-Bromo-3,5-dimethyl-phenyl)-5-methyl-[1,2,4]oxadiazole
Reaction equation
C(O[C:5](=[O:7])[CH3:6])(=O)C.[Br:8][C:9]1[C:18]([CH3:19])=[CH:17][C:12]([C:13]([NH:15]O)=[NH:14])=[CH:11][C:10]=1[CH3:20]>N1C(C)=CC(C)=CC=1C>[Br:8][C:9]1[C:18]([CH3:19])=[CH:17][C:12]([C:13]2[N:14]=[C:5]([CH3:6])[O:7][N:15]=2)=[CH:11][C:10]=1[CH3:20]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
Acetic anhydride (0.35 mL) is added to a solution of 4-bromo-N-hydroxy-3,5-dimethyl-benzamidine (0.30 g) in collidine (3 mL) at room temperature. The solution is stirred at room temperature for 1 h and then at 120° C. for 3 h. After cooling to room temperature, the mixture is concentrated, the residue is taken up in water and acetonitrile, and the resulting mixture is filtered. The filtrate is chromatographed on reversed phase (HPLC; acetonitrile/water/trifluoroacetic acid) to give the title compound. LC (method 11): tR=1.20 min; Mass spectrum (ESI+): m/z=267/269 (Br) [M+H]+.