ABSTRACT The series of ibuprofen compounds (1–5) have been synthesized. Acid chloride (4-isobutylphenyl) acetyl chloride (1) was obtained from interaction ibuprofen with thionyl chloride, this compound (1) was treated with hydrazine to give acid hydrazide 2-(4-isobutylphenyl) acetohydrazide (2). Schif’s base of 2-(4-isobutylphenyl) acetohydrazide derivatives (3a–e) were prepared by refuxing (2) with diferent aromatic aldehydes and ketones. The (4-isobutylphenyl) acetyl chloride (1) converts to esters (4a–f) by reacting with alcohols, and with secondary amines to give amide compounds of (4-isobutylphenyl) acetyl chloride (5a–b). All structures of synthesized compounds have been confrmed by elemental analysis (C, H, and N) and spectral data (FT-IR and 1 H NMR). The prepared compounds (3a–e) and (4a–f) have been screened for their antibacterial activity for S. aureus, B. subtilis, E. coli, P. aeuroginosa, and were shown to have antibacterial activity. Keywords: (4-isobutylphenyl) acetyl chloride, Amide derivatives, Antibacterial activity, Ibuprofen derivatives, Schif’s base. International Journal of Drug Delivery Technology (2020); DOI: 10.25258/ijddt.10.3.26 How to cite this article: Thejeel KA. Synthesis and characterization of some new ibuprofen derivatives and study antibacterial activity. International Journal of Drug Delivery Technology. 2020;10(3):454-458. Source of support: Nil. Confict of interest: None Synthesis and Characterization of some new Ibuprofen Derivatives and Study Antibacterial Activity Khalida A. Thejeel * Department of Geophysics, College of Remote Sensing and Geophysics, University of Al-Karkh for Science, Iraq Received: 14th June, 2020; Revised: 05th July, 2020; Accepted: 10th August, 2020; Available Online: 25th September, 2020 INTRODUCTION Ibuprofen is 2-[4-isobutyl phenyl] propionic acid, Figure 1, it is the frst of propionic acid derivatives introduced as a better alternative to aspirin in 1969. 1 It is a nonsteroidal anti- infammatory drug (NSAID) with pronounced analgesic and antipyretic properties. 2 Various ibuprofen derivatives have been prepared to reduce side efects. 3-5 Recently, the profens have been come to demented this therapeutic class. Some of the available profen drugs are ibuprofen, naproxen, ketoprofen, and furbiprofen. 6 Ibuprofen is given as esters, various salts, free acid, and other complexes are also used. These include lysing and salt of sodium, pyridoxine and guaiacol esters, and meglumine and iso-butanol ammonium derivatives. 7-9 Ibuprofen is used to relieve the symptoms (wide range) of illnesses, such as, headaches, backaches, period pain, cold and fu, migraine symptoms, and arthritis. 10 Ibuprofen is produced as a racemate. It contains a chiral center in α-position of the propionate, it has two enantiomers, (S), and (R); the two enantiomers have diferent RESEARCH ARTICLE metabolism and biological efects, the S−(+) − the active form for ibuprofen. 11,12 MATERIAL AND METHODS Apparatus and Chemicals All reagents and solvents are used from Merck, Fluka, and BDH. Melting points were recorded using hot stage Gallen Kamp melting point and uncorrected, England. Thin-layer chromatography (TLC) was carried out using Fertigfollen recoated sheets type polygram Silg, and the plates were developed with iodine vapor. Infrared spectra have been recorded using Shimadzu (8300) (FT-IR) infrared spectrometer, KBr disc in 4,000 to 600 cm -1 spectral range. 1 H NMR spectra have been recorded using NMR Spectrometer 400MHz, Bruker, Germany, using tetra methyl saline (internal standard) and DMSO-d 6 (solvent). The elemental analyses of C, H, and N have been performed using the Perkin-Elmer 240C analyzer. Methods of Synthesis Synthesis of (4-Isobutylphenyl) Acetyl Chloride (1) 15 A 0.01 mole (ibuprofen) was added to a 50 mL round bottom fask with stirring. In the ice bath, the reaction was cooled for 10 minutes and 10 mL thionyl chloride was then introduced into the reaction. After 25 minutes reaction, the reaction *Author for Correspondence: khalidath1971@yahoo.com O OH Figure 1: Ibuprofen