CRYSTAL-STRUCTURE OF 4-BROMO-2-METHOXY-1- METHYL-5-NITROIMIDAZOLE AND4-BROMO-2-CYANO-1-METHYL-5-NITROIMIDAZOLE PREPARED BY NUCLEOPHILIC-SUBSTITUTION FROM 2,4-DIBROMO-1-METHYL-5-NITROIMIDAZOLE

Reaction of 2,4-dibromo-1-methyl-5-nitroimidazole 1 with sodium methox ide in methanol or with potassium cyanide in DMSO implies univocal nuc leophilic substitution of 2-bromine atom by methoxy or cyano group as revealed by the crystalline structures of 4-bromo-2-methoxy-1-methyl-5 -nitroimidazole 2 and 4-bromo-2-cyano-1-methyl-5-nitroimidazole 3. Com pound 2 (C5H6BrN3O3) crystallizes in the monoclinic system, space grou p P2(1)/c, a = 13.433(5) Angstrom, b = 9.065(2) Angstrom, c = 14.027(5 ) Angstrom, beta = 103.99(2)degrees, Z = 8. The 4-bromo-2-cyano-1-meth yl-5-nitroimidazole 3 (C5H3BrN4O2) crystallizes in the monoclinic syst em, space group P2(1), a = 9.705(9) Angstrom, b = 6.328(2) Angstrom, c = 25.809(9) Angstrom, beta = 95.44(4)degrees, Z = 8. Structures found by molecular mechanics are in good agreement with the solid state geo metries.