Reported procedures mainly use fuming nitric acid (concentration >86 %) with or without conc. H2SO4 to nitrate quinazolineones, however the only available concentration for me is 69%, can it nitrate it or it should be fuming?
No, dilute nitric acid cannot be concentrated beyond 68% by boiling. It can be concnetrated b y distilling it with concentrated sulphuric acid under reduced pressure . Most commercially available nitric acid has a concentration of 68% in water. When the solution contains more than 86% HNO 3, it is referred to as fuming nitric acid. This mixture boils constantly at constant boiling point without any change in its composition. At this temperature, the gas and the water vapour escape together. Hence the composition of the solution remains unchanged. So nitric acid cannot be concentrated beyond 68% by distillation of dilute solution of HNO3.Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%.Fuming nitric acid is a commercial grade of nitric acid that has a very high concentration and a high density. Moreover, it forms a colorless, yellowish or brownish fume. The lowest concentration of this acid is 90%. Concentrated nitric acid is simply a solution containing more nitric acid in less water.
https://apps.dtic.mil/sti/pdfs/ADA396283.pdf
https://www.tsijournals.com/articles/quinazoline-derivatives-with-potent-antiinflammatory-and-antiallergic-activities.pdf
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