Nitric Acid → 2-Methyl-5-nitroimidazole

Participants

Reaction Steps

In a bottle of 1 liter capacity, an untreated mixture obtained by nitration of the 2-methylimidazole as in examples I, III and V were placed and while stirring and mixing, 100 g of 2-methylimidazole were dissolved in such a manner, that the temperature did not exceed 70°. Then a reflux-condenser was connected and 200 ml of nitric acid of a density of about 1.50 were added, and thereafter sulphuric acid of 1.84 density was gradually introduced such that the temperature increased to 110°. The reaction, which started at once without delay, was intensive with violent liberation of nitric oxides. Then as the intensity of the reaction declined, further quantities of sulphuric acid were added until exhaustion of a quantity of 100 ml, and after the exothermic effect diminished the reflux condenser was changed to a normal one, whereby the temperature of the mixture increased to about 140° by simultaneous distilling off several ml of volatile components. After the reaction the solution was divided, and 1/3 remained for the treatment in the same way as the following charge and from the remaining 2/3 of the solution there were isolated 98 g of 2-methyl-5-nitroimidazole corresponding to about 66% of theoretical.

Provenance & Evidence