Mikdad T. Ayoub

New palladium(II) complexes bearing pyrazole-based Schiff base ligands: Synthesis, characterization and cytotoxicity

Reactions of 5-hydrazino-1,3-dimethyl-4-nitro-1H-pyrazole (1) with substituted benzaldehydes (2-5) in methanol gave the new substituted benzaldehyde (1,3-dimethyl-4-nitro-1H-pyrazol-5-yl)hydrazone Schiff base ligands (6-9) benzaldehyde (1,3-dimethyl-4-nitro-1H-pyrazol-5-yl)hydrazone (H-BDH, 6), 2,3-dimethoxybenzaldehyde (1,3-dimethyl-4-nitro-1H-pyrazol-5-yl)hydrazone (MeO-BDH, 7), 4-chlorobenzaldehyde (1,3-dimethyl-4-nitro-1H-pyrazol-5-yl)hydrazone (Cl-BDH, 8), and 4-hydroxybenzaldehyde (1,3-dimethyl-4-nitro-1H-pyrazol-5-yl)hydrazone (OH-BDH, 9) in moderate to excellent yields. Reactions of these pyrazole-based Schiff bases with [PdCl(2)(NCPh)(2)] in acetone at room temperature gave the trans-palladium(II) complexes trans-[PdCl(2)(L)(2)] (10-13) (L=6-9). The isolated compounds were characterized by their physical properties, elemental analysis, IR-, MS (EI)- and NMR-spectroscopy. The cytotoxic effect of these complexes against the fast growing head and neck squamous carcinoma cells SQ20B and SCC-25 has been studied. The influence was dose dependent and varies by cell type. The complexes 11, 12, and 13 had higher clonogenic cytotoxic effect than cisplatin when tested on SQ20B cell line.

Synthesis and antitumor activity of 2-aryl-7-fluoro-6-(4-methyl-1-piperazinyl)-4(3H)-quinazolinones

A series of new 2-aryl-7-fluoro-6-(4-methyl-l-piperazinyl)-4(3H)-quinazolinones were prepared by the oxidative cyclization of the corresponding 2-arylidineamino-4-fluoro-5-(4-methyl-1-piperazinyl)benzamides. The new quinazolinones were evaluated for their antitumor activity.

Synthesis, characterization, and antimicrobial activity of some new coumarin derivatives

A number of new [(4-methyl-2-oxo-2H-chromen-7-yl)amino]methylcoumarins (5a–c), benzofuran (6), and benzoxazol (7) were synthesized through the reaction of 7-amino-4-methylcoumarin (1) with a number of organic halides. In addition, series of N-substituted 2-[(4-methyl-2-oxo-2H-chromen-7-yl)oxy]acetohydrazide (11a–h) and (12a–d) were prepared from the reaction of 2-[(4-methyl-2-oxo-2H-chromen-7-yl)oxy]acetohydrazide (8) with corresponding heteroaryl/alkyl halides (2–4, 9, and 10). The synthesized compounds were characterized by elemental analysis and by spectroscopic techniques such as 1H-NMR, 13C-NMR, and mass spectrometry and were tested for their in vitro antimicrobial activity. The newly synthesized compounds exerted significant inhibitory activity against the growth of tested bacterial strains and a few of them are found to be potent antimicrobial agents.

Synthesis of Some 1,3-Dimethyl-6-substituted-1H-pyrazolo[3,4-b]pyrazin-5(4H)-ones

A series of new 6-substituted-1,3-dimethyl-1H-pyrazolo[3,4-b]pyrazin-5(4H)-ones (13a - e) and 1,3-dimethyl-5a,6a,7,8-tetrahydro-1H-pyrazolo[4,3-e]pyrrolo[1,2-a]pyrazin-5(4H)-one (15) have been synthesized. The synthetic strategy involves direct interaction of D,L-α-amino acids with 5- chloro-1,3-dimethyl-4-nitro-1H-pyrazole (10) to produce the respective N-(1,3-dimethyl-4-nitro-1Hpyrazol- 5-yl) D,L-α-amino acids 11a - e and 14. The latter compounds underwent reductive lactamization to deliver the corresponding target heterocyclic systems 13a - e and 15 Graphical Abstract Synthesis of Some 1,3-Dimethyl-6-substituted-1H-pyrazolo[3,4-b]pyrazin-5(4H)-ones

Preparation of some alkenoic acid derivatives as new plant growth regulators

A number of 3-alkoxy-5-substituted-2,4-alkadienoic acids (4a–f) have been synthesized from the reaction of ethyl (E)-3-alkoxy-2-butenoate with different ketones in the presence of KOH in DMSO. Similarly, several (2Z,4E)-5-[4-(benzylthio)phenyl]-3-alkoxyhexa-2,4-dienoic acids were prepared via condensation of ethyl (E)-3-alkoxy-2-butenoate with 4-(benzylthio)acetophenone in the presence of KOH in DMSO. The structures of all synthesized compounds were confirmed by IR, 1H NMR, 13C NMR, and MS spectra and by elemental analysis.