SALICYLDEHYDE AZINE
Salicylaldehyde azine is used in the preparation of 2-oxo-2H-1-benzopyran-3-carboxylic acid 2-(2-oxo-2H-1-benzopyran-3-carbonyl)hydrazide by reacting with propadienedione . It has anthelmintic activity.
Salicylaldehyde is converted to chelating ligands by condensation with amines. With ethylenediamine, it condenses to give the ligand salen. Hydroxylamine gives salicylaldoxime. Condensation with diethyl malonate gives 3-carbethoxycoumarin (a derivative of coumarin) by an aldol condensation.
Salicylaldehyde is prepared by heating phenol and chloroform together in the presence of potassium hydroxide and sodium hydroxide. This reaction is called the Relmer-Tiemann reaction. The correct option is Option C, Reimer-Tiemann reaction.
Salicylic acid can be synthesized from salicylaldehyde using KMnO4 without oxidising the hydroxy group (−OH). The hydroxy group that attached to the benzene isn't oxidized, because the C atom that bonded with the hydroxy has already use 2 electrons for sigma bonding and 1 electron for pi bonding.