ChEBI: A hydrazone resulting from the formal condensation of both of the aldehyde groups of anthracene-9,10-dicarbaldehyde with 2-hydrazinyl-4,5-dihydro-1H-imidazole.
A 33.0 g (0.135 mole) of 2-methylthio-2-imidazoline hydroiodide is dissolved
in 300 ml of water and treated with 8 ml (0.16 mole) of hydrazine hydrate.
The mixture is stirred at room temperature for 20 hours and then taken to
dryness under reduced pressure. The residue is dissolved in 250 ml of water
and again taken to dryness under reduced pressure. The residue is
redissolved in 250 ml of water and added to a mixture of 250 ml of water, 25
ml of concentrated hydrochloric acid and 25 g of silver oxide. The resulting
mixture is stirred on a steam bath for 4 hours and then filtered. The filtrate is
reduced to dryness under reduced pressure. The residue is dissolved in 300
ml of ethanol and 20 ml of water at the boil, clarified and cooled at -10°C.
The precipitate is collected, washed with ethanol and ether and dried at 60°C
and then 110°C under reduced pressure. Yield of the 2-hydrazino-2-
imidazoline hydrochloride 11.6 g, melting point 177-180°C.
The 2-hydrazino-2-imidazoline monohydrochloride is converted to the
dihydrochloride by treatment with ethanol and concentrated hydrochloric acid.
A suspension of 3.46 g of the 2-hydrazino-2-imidazoline dihydrochloride and
2.34 g of 9,10-anthracenedicarboxaldehyde in 100 ml of ethanol is stirred and
heated under reflux for two hours. The mixture is cooled and the solid is
collected and washed with ethanol giving the desired product as a crystalline
orange solid, m.p. 288-289°C (dec.).
