A Simple and Practical Synthesis of 2-Aminoimidazoles

Article abstract of DOI:10.1021/jo00103a021

A new and simple two-step procedure to synthesize 2-aminoimidazoles (2-AI's) from readily available materials has been developed.The cyclization reaction of α-halo ketones and N-acetylguanidine in acetonitrile (MeCN) at reflux, or in dimethylformamide (DMF) at ambient temperature, gives 4(5)-substituted and 4,5-disubstituted N-(1H-imidazol-2-yl)acetamides, which are then hydrolyzed to their respective 2-AI's.In general, the purified products were isolated in good yields.We have prepared several examples and have demonstrated the usefulness of this method by its application in the total synthesis of 8, an interesting histamine analog, and oroidin, 15, a marine natural product isolated from various sponges.