Hexamethyldisilazane → Ethyl 1-cyclopropyl-2,5-dimethyl-1H-imidazole-4-carboxylate
Reaction equation
S([O-])([O-])(=O)=O.[NH4+].[NH4+].[CH2:8]([O:10][C:11](=[O:23])[C:12]([NH:19][C:20](=O)[CH3:21])=[C:13]([NH:15][CH:16]1[CH2:18][CH2:17]1)[CH3:14])[CH3:9].C[Si](C)(C)N[Si](C)(C)C>>[CH2:8]([O:10][C:11]([C:12]1[N:19]=[C:20]([CH3:21])[N:15]([CH:16]2[CH2:18][CH2:17]2)[C:13]=1[CH3:14])=[O:23])[CH3:9]Participants
4
Conditions
- Temperature
- 145 °C
Procedure
Fine powdered ammonium sulfate (0.13 g, 1 mmol) was added to a suspension of Z)-2-acetylamino-3-cyclopropylamino-but-2-enoic acid ethyl ester (7.0 g, 20 mmol) and hexamethyldisilazane (50 ml, 235 mmol) and refluxed over night at 145° C. The reaction mixture was evaporated and extracted with ethyl acetate and water. The organic phase was dried over sodium sulfate and evaporated. The crude product was purified by column chromatography on silica gel (ethyl acetate/methanol 4:1) and the desired compound was obtained as a light brown solid (1.3 g, 31%), MS: m/e=209.1 (M+H+).