Studies on derivatives of 4-hydroxycoumarin. V. Condensation products of aromatic dialdehydes with 4-hydroxycoumarin
Dissert Pharmaceut 15(1): 29-33
The course of the reaction between aromatic dialdehydes and 4-hydroxycoumarin was studied for the first time using terephthalic aldehyde and naphthylene-l,4-dialdehyde. As products of condensation [omega]), [omega]'-[phenylene-l,4]-bis-dicoumarol and ([omega],[omega]'-[naphthylene-l,4]-bis-dicoumarol were obtained with fairly good yields. By the action of dehydrating agents (acetic anhydride in pyridine) on these products, the respective epoxydicoumarins were obtained. Naphthylene-l,4-dialdehyde is a little known compound and was characterized through bis-isonicotinoylhydrazone. Moreover, the yield of naphthylene-1,4-dialdehyde can be increased from 12% to about 80% in the reaction of hydrolysis of the urotropine salt of 1,4-dichloromethylnaphthalene with 50% acetic acid.