Synthesis, Characterization and Antimicrobial Activity of Some Hydroxypyrazolines

New hydroxypyrazolines were obtained starting from some hydrazides. 4-(4-X-Phenyl-sulfonyObenzoic acid hydrazides la-c were treated with 1,1,1 -trifluoroacetylacetone in order to obtain new corresponding pyrazole compounds. However, formation of desired pyrazoles from these hydrazides failed and instead new hydroxypirazolines intermediates 2a-c were obtained. Also, by reaction of 2-0-(4-(4-chlorophenylsulfonyl)phenyl)-4-(2-fluorophenyl)-4H-1,2,4-triazol-3-ylthio)acetohydrazide 6b with 1,1,1-trifluoroacetylacetone was obtained the new hydroxypirazoline 7b and not corresponding pyrazole. The new hydrazide 6b was obtained by reaction of ethyl 2-0-(4-(4-chlorophenylsulfonyl)phenyl)-4-(2fluoropheny1)-4H-1,2,4-triazol-3-ylthio)acetate 5b with hydrazine hydrate. The new ester 5b was obtained by alkylation of corresponding 1,2,4-triazol-3-thione with ethyl bromoacetate in basic media. By reaction of hydrazide la with ethyl (4,4,4-trifluoroacetyl)acetate did not occur expected pyrazolone and the acylhydrazone intermediate 3a. The structures of these compounds were elucidated by elemental analysis and IR, UV, H-1-NMR, C-13-NMR, MS spectra. The hydroxypyrazoles obtained were tested for their antimicrobial activity.