Bromo-formyl imidazoles 16-20 have been prepared by three
different ways. The first consisted of conversion of bromo or iodo
imidazoles 1-6 into diethyl acetals 13-15, and subsequent hydrolysis
into formyl derivatives 7-9. In the second, bromination of.
formyl imidazoles with NBS afforded compounds 16-18 in 45-70°/o
yield. The third method used direct formylation of bromo imidazoles
10-12 with n-BuLi/DMF reagent into compounds 16, 19, and 20