<span style="font-size:11.0pt;font-family: "Times New Roman","serif";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI;mso-bidi-font-weight:bold" lang="EN-GB">Synthesis, characterization and antimicrobial evaluation of <span style="font-size:11.0pt;font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman";mso-bidi-font-family:Mangal; mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-GB">(<i style="mso-bidi-font-style:normal">E</i>)- 4-(substitutedphenyl)-<i style="mso-bidi-font-style:normal">N</i>'-(1-phenylethylidene)cyclohexane carbohydrazide derivatives</span></span>

718-723<span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:minionpro-regular;mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">Encouraged by the various biological activities associated with hydrazone derivatives, the present paper describes the synthesis, characterization and antimicrobial evaluation of (<i style="mso-bidi-font-style: normal">E)-4-(substituted phenyl)-N'-(1-phenylethylidene) cyclohexanecarbohydrazide derivatives 4a-k from commercially available <span style="font-size:11.0pt; font-family:" times="" new="" roman","serif";mso-fareast-font-family:advot863180fb;="" mso-bidi-font-family:mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">4-(4-chlorophenyl)cyclohexanecarboxylic acid. The hydrazide-hydrazone derivatives 4a-k have been synthesized via the nucleophilic addition-elimination reaction of substituted acetophenones a-k with 4-(4-chlorophenyl)cyclohexanecarbohydrazide 3<span style="mso-bidi-font-weight: bold">. <span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:advot863180fb;mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">The structures of the synthesized compounds are confirmed by 1H NMR, IR and mass spectral data. <span style="font-size:11.0pt; font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">All the synthesized 4-(4-chlorophenyl)cyclohexane carbohydrazide derivatives 4a-k have been evaluated for their in vitro antibacterial activity against Staphylococcus aureus and Staphylococcus pyogenes <span style="mso-bidi-font-style: italic">(gram positive bacteria) and Escherichia coli and Pseudomonas aeruginosa (gram negative bacteria). The antibacterial screening results reveal that compounds 4f-j exhibit good antibacterial activity with zone of inhibition 21-25 mm while the compounds 4a-c show moderate antibacterial activity with zone of inhibition 16-20 mm whereas the compounds 4d, <b style="mso-bidi-font-weight: normal">4e and 4k show nil activity.