Beiträge zur Chemie von Tetraketonen, III Synthese und einige Reaktionen des 1,6-Bis(p-hydroxyphenyl)-1,3,4,6-hexantetrons
Contributions to the Chemistry of Tetraketones, III. - Synthesis and Some Reactions of 1,6-Bis(p-hydroxyphenyl)-1,3,4,6-hexanetetrone 
 
 
 
Condensation of p-hydroxyacetophenone and diethyl oxalate in the presence of sodium ethoxide gave the tetraketone 3 which can be cyclized with o-phenylenediamine, hydrazine, or phenyl-hydrazine to yield the quinoxaline 1 or the 3,3′-bipyrazolyl derivatives 5 and 6, respectively. Transformation of the p-hydroxyphenyl group in compounds 1 and 3 with methyl isocyanate/triethylamine gave the corresponding carbamates 2 and 4. By condensation of 4 with hydrazine or phenylhydrazine the pyrazoles 7 and 8 were prepared. Compounds 4, 7, and 8 showed no progressive inhibitory properties against acetylcholinesterase.