Method of preparing the azomycine and its homologous

摘要

2-Nitroimidazoles, mostly novel, of the general formula FORM:1114154/C2/1 (wherein R represents H or a C1- 8 alkyl group, R1 represents a C1- 8 alkyl group and n is 0, 1 or 2) are prepared by contacting the corresponding 2-aminoimidazoles with about an equimolecular amount of an alkali metal nitrite in 15-65% (by weight) HBF4 and treating the resulting solution with at least an equimolecular amount of an alkali metal nitrite in water in the presence of copper powder as catalyst. 1,5 - Dimethyl - 2 - aminoimidazole is prepared by heating cyanamide with a -methylaminopropionaldehyde acetal in aqueous acetic acid to form 1 - methyl - 1 - [2 - (1,1 - diethoxy) - propyl]-guanidine acetate and heating this in conc. HCl.