The current work involves synthesis of 6-amino-4-(4-hydroxyl-3-methoxyphenyl)-3-methyl-1-phenyl-1,4- dihydropyrano[2,3-c]pyrazole-5-carbonitrile (2) by condensation of 2-(4-hydroxyl-3-methoxybenzylidine) malononitrile (1) with 3-methyl-1-phenyl-2-pyrazolin-5-one. The product 2 was then reacted with various aldehydes to form a series of Schiff base derivatives 3a-h. The reaction of the chosen Schiff base derivatives (3a and 3b) with mercaptoacetic acid gave thiazolidinone derivatives (4a and 4b). The structures of prepared compounds were confirmed using FT-IR, 1H NMR, and 13C NMR spectroscopies.  They were evaluated as good copper corrosion inhibitors, anti-rust, and antioxidants. This was done by mixing them with the base medium lubricating oil (type 60 stock) provided by the Iraqi Midland Refineries Company/Al-Daura according to the American Society of Testing and Materials ASTM-D130, ASTM-D665, and Institute of Petroleum's testing method, oxidation stability test (IP-280), respectively.

The use of multifunction additives in the lubricant sector has attracted great interest due to their ability to simultaneously improve and add multiple functions. This work describes the preparation and evaluation of over-based magnesium stearate detergent as a multifunction additive by the reaction of stearic acid with carbon dioxide gas in the presence of magnesium oxide nanoparticles and ammonia. The prepared over-based magnesium stearate was evaluated as a multifunction additive through blending it in various concentrations of 1-5 wt/wt% with sixty stock lubricating oils. The American Society for Testing and Materials (ASTM) and the Institute of Petroleum (IP) were used to determine the total base number (TBN), viscosity index (VI), pour point (PP), rust prevention, copper corrosion inhibition, and oxidation stability. The over-based magnesium stearate detergent gave higher values for TBN and detergency efficiency. The blended oil with one percent of the prepared additive showed more rust, oxidation, and corrosion resistance than the standard antioxidant (hindered phenol HP). The VI values of the blended oils showed that the 5 wt/wt% over-based magnesium stearate, which has approximately the same VI values as the blend with 5% of the standard olefin copolymer (OCP), provides better performance.

Aminomethylene Meldrum’s acid derivatives were synthesized by a three-component, one-pot reaction of Meldrum's acid with triethyl orthoformate and different aromatic amines. The prepared compounds were characterized using Fourier transform infrared (FT-IR), nuclear magnetic resonance (1H NMR and 13C NMR) and evaluated as anti-corrosion and anti-rust additives by blending with base lubricating oil, according to the American Society of Testing and Materials (ASTM-D130 and ASTM-D665). The blends of the synthesized compounds with the base lubricating oil showed better anti-rust and anti-corrosion effects than the base oil Blank).

A series of overbased magnesium fatty acids such as caprylate, caprate, laurate, myristate, palmitate, stearate and oleate) were synthesized by the reaction of the fatty acids with active – 60 magnesium oxide and carbon dioxide (CO2) gas at 60 oC in the presence of ammonia solution as catalyst, toluene / ethanol solvent mixture (9:1vol/vol) was added.The prepared detergent additives were characterized by FTIR, 1HNMR and evaluated by blending each additive in various concentrations with medium lubricant oil fraction (60 stock) supplied by Iraqi Midland Refineries Company. The total base number (TBN, mg of KOH/g) was determined, and the results of TBN were treated by using two-way analysis of variance (ANOVA) test. It was found that the number of carbons in the fatty acid (C8-C18) used for overbased detergent preparation had slight effect on the TBN of the oil, while detergent concentrations (1-5% wt/wt) had a significant effect on the TBN of the blended oil.The oxidation stability of the oil blends with 2% of overbased magnesium palmitate and overbased magnesium stearate detergents was evaluated, and the results showed that these blends gave higher oxidation stability compared with the blends with standard antioxidant supplied by Midland Refineries Company.