The demethylation ot o-vanillin (I) with AlCl3 dissolved in pyridine gives 2,3 dihydroxybenzaldehyde (II). Subsequent alkylation by means of hexyl bromide with NaH gives 3-hexyloxy-2-hydroxybenzaldehyde (III), which is then condensed with malononitrile and piperidine, yielding 3-cyano-8-hexyloxycromen-2-one (IV), a needle-like yellow crystalline substance. Finally, compound (IV) is treated with sodium azide and AlCl3 in refluxing THF, yielding the formation of the tetrazole ring.