Dissolve 70 g of potassium permanganate in 1 L of water followed by 4g of NaOH and 40 mL of heptanol, stir for 5h and allow the stand for 24h at room temperature, filter and pour the filtrate into an evaporation dish. The residue is treated with 75 mL of conc. sulfuric acid and washed several times with water until no more acid remains, the crude product is then dried over anhydrous calcium chloride and it is distilled at 222-223°C.
Evaporation of the residual water from the filtrate
Washing the residue with the sulfuric acid and water
Drying the distilled product