Add solution made from 14.5 g of potassium permanganate and 150 mL of water, slowly over 2h, with stirring to a suspension made from 10 mL of veratraldehyde and 60 mL of water, the mixture should be heated at 60°C. Then the mixture let to stand for 5h at room temperature and it is filtered and washed with some hot water. The filtrate is acidified to pH of 4 with conc. HCl with stirring and then filtered. The crude product is recrystallized from hot ethanol.
Addition of the oxidative solution
Acidification of the solution with the HCl
The crude filtered product
The recrystallized pure product