Acetyl-5-methyl-2-vinylimidazole

Allylamine (0.415 ml, 5.05 mmol) is added to a solution of 3-hydroximino-2,4-pentanedione (0.645 g, 5 mmol) in anhydrous acetonitrile (5 ml). The violet 

Less common as a synthetic method is the rearrangement under mild conditions of some hydrazinium salts. In contrast to the severe conditions necessary (200 C, solid KOH) to rearrange 1,1,1-trialkylhydrazinium salts [60], 1,1-dimethyl-l-phenacylhydrazinium bromide is transformed merely by refluxing in pentanol or pyridine into 2-benzoyl-4-phenylimidazole (65-73%). This is a Stevens-type rearrangement [61, 62]. 

Suzuki, T. Iwasaki, K. Matsumoto and Y. Iwasawa, Chem. Pharm. Bull. 32, 2536 (1984). 

Yamanaka, M. Mizugaki, T. Sakamoto, M. Sagi, Y. Nakagawa, H. Takayama, M. Ishi-bashi and H. Miyazaki, Chem. Pharm. Bull. 31, 4549 (1983). 

Bcnjes and M. R. Grimmen, unpublished (P. Benjes, Ph.D. thesis. University of Otago. New Zealand, 1994). 

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