Triethyl orthoacetate → 2-Methyl-5-(3-nitro-5-(trifluoromethyl)phenyl)-1,3,4-oxadiazole
Reaction equation
[N+:1]([C:4]1[CH:5]=[C:6]([CH:11]=[C:12]([C:14]([F:17])([F:16])[F:15])[CH:13]=1)[C:7]([NH:9][NH2:10])=[O:8])([O-:3])=[O:2].[CH2:18](OC(OCC)(OCC)C)[CH3:19]>>[CH3:18][C:19]1[O:8][C:7]([C:6]2[CH:11]=[C:12]([C:14]([F:15])([F:16])[F:17])[CH:13]=[C:4]([N+:1]([O-:3])=[O:2])[CH:5]=2)=[N:9][N:10]=1Participants
3
Procedure
A mixture of 3-nitro-5-(trifluoromethyl)benzohydrazide (20 g, 80 mmol) in 1,1,1-triethoxyethane (156 g, 963 mmol) was heated to reflux and stirred for 12 h. Then the solvent was concentrated to yield a black solid of 2-methyl-5-(3-nitro-5-(trifluoromethyl)phenyl)-1,3,4-oxadiazole (20 g, 65.9 mmol, 82% yield): 1H NMR (400 MHz, CD3OD) δ 9.04 (s, 1H), 8.71 (s, 1H), 8.66 (s, 1H), 2.67 (s, 1H); ES-LCMS m/z 274 (M+H).
Workup
- temperaturewas heated
- temperatureto reflux