Imidazoles, 2-acyl 1- acylamino

Oxo-l-propenylamino)-l,2,4-oxadiazole lagern sich mit Natriumethanolat in Dimethyl-formamid in Ausbeuten von 60-80% in 4(5)-Acyl-2-acylamino-imidazole um392 ... 

Such substrates as a-(acylamino)enaminones (4) can be made by catalytic reduction of acylated 4-aminoisoxazoles (3) [16, 17J, or acetamidines made from 4-amino-5(4/f)-isoxazolones [18]. Although the starting materials require multistep syntheses, they are quite readily available in high yields, and their reduction and transformation into imidazoles are often quantitative (see Section 6.1.2(e)). 

Reaction of bis(triphenyl) oxodiphosphonium trifluoromethanesulfonate salt with 3-tosylamino-a-acylamino esters 78 led to a highly efficient enantiospecific synthesis of imidazolines 79 <04OL1681>. AT-Acylated a-aminonitriles 80 were reacted with triphenylphosphine and carbon tetrachloride to afford 2,4-disubstituted 5-chloro-l//-imidazoles 81, which could undergo Suzuki palladium-catalyzed reactions <04OL929>. 

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