Synthesis of 4‐aroyl‐5‐nitro‐1H‐imidazoles and 4‐aroyl‐5‐aminoimidazoles

Abstract

The reaction of α‐(aryl)‐4‐morpholineacetonitriles (masked aroyl anion equivalents) with N‐protected 4(5)‐bromo‐5(4)‐nitro‐1H‐imidazoles gave 4‐aroyl‐5‐nitroimidazoles which were reduced to afford 4‐aroyl‐5‐aminoimidazoles.

Properties of haloimidazoles (review)

“…The respective 1-acyl derivatives 42a,b [17,36], 43 [37], and 44 [38] were obtained with yields of 80-99% by the reaction of 4(5)-bromo(fluoro)imidazoles 11 and 41 with acetic anhydride, of 4,5-dichloroimidazole 6 with chloroformic ester, and of tribromoimidazole 1 with aroyl chlorides. The reaction of 4(5)-iodoimidazole (45) with N,N-dimethylchlorosulfamide leads to a 9:1 mixture of the isomeric products 46 and 47 (total yield 97%) [39].…”

Methods of synthesis of halogenonitroimidazoles (review)

“…Nitration of 2-bromo-1-methylimidazole (XXVII) formed a mixture of two isomers XXVIII and XXIX in overall yield 45% with a 4-nitro/5-nitro ratio of 2:1 [49].…”

The Chemistry of Deprotonated α-Aminonitriles

“…147,148 Albright and Moran used their rugged lithiated (morpholin-4-yl)arylacetonitriles 170, which often give superior results compared to dialkylamino substituted nucleophiles, 149,150 to effect halide substitution on 1-benzyl-5-bromo-2-methyl-4-nitroimidazole. 151 The primary products were subsequently converted into the corresponding aryl ketones 172 by treatment with copper sulfate pentahydrate (Scheme 28, top). The same type of nucleophile permitted the conversion of 4-fluoronitrobenzene into 3-methoxy-4¢-nitrobenzophenone (Scheme 28, bottom).…”