STUDIES ON THE VILSMEIER-HAACK REACTION: PART XIII. NOVEL HETEROCYCLO-SUBSTITUTED 4,4′-bi-PYRAZOLYL DITHIOCARBAMATE DERIVATIVES

Abstract

5-Imino-3-methyl-1-phenyl-2-pyrazoline-4-dithiocarbamic acid (I) underwent simultaneous formylation and dimerization reactions with the Vilsmeier reagent giving 4-[5′-imino-3-(1”-formyl-2”-dimethylaminoethenyl)-3′-methyl-1′-phenyl-1′H-pyrazolo-4′-dithiocarbamyl-2,4-dihydro-3-imino-5-methyl-2-phenyl-1-pyrazoline]dithiocarbamate (II) which hydrolyzed with sodium hydroxide to give 4-[3′-(1”-formyl-2”-hydroxyethenyl)-3′-methyl-1′-phenyl-1′H'-pyrazolo-4-dithiocarbamyl-1′-pyrazoline]dithiacarbamate-5,5′-dione (IV). Treatment of II and/or IV with morpholine, piperidine, piperazine, hydroxylamine, hydrazine hydrate, phenylhydrazine) afforded the corresponding dipyrazolo-4,4′-dithiocarbamate derivatives with different heterocyclic systems at the 3-position. The structures of these compounds were confirmed by elemental, IR, and ¹H-NMR analyses. All synthesized compounds have been screened in vitro against Gram-positive, Gram-negative bacteria and fungi.

Key Words:

• Imino-piperidine
• morpholine
• piperazine
• isoxazole-bi-(pyrazolyl dithiocarbamate) and biological screening