Suggest a mechanism to account for Step 1 in the sequence. (3 marks) 

 

2 equivalents heat in acetic acid C-C H NH3 + N. NH H3C Step 1 H3 1. conc. HNO3/ conc. H2SO4 Step 2 2. neutralisation NO2 NO2 NO2 N. NH HN N OH Step 3 CH3 CH3 CH3 2-methyl-4(5)-nitroimidazole metronidazole