6-Amino-4-(4-hydroxyphenyl)-5-cyano-3-methyl-1-phenyl-1, 4-dihydropyrano [2,3-c] pyrazole (compound 2) was prepared by condensation of 2-(4-hydroxylbenzylidine) malononitrile (compound 1) [which was prepared by Knoevenagel condensation of malononitrile with 4-hydroxy benzaldehyde ] with 3-methyl-1-phenyl-2-pyrazolin-5-one. Reactions of compound 2 with different reagents formic acid, formamide, and ammonium thiocyanate under microwave irradiation leads to the synthesis of 4-(4-hydroxyphenyl)- 3-methyl-1-phenyl-4,6-dihydro- pyrazolo [3', 4':5,6] pyrano [2,3-d] pyrimidine-5-one (compound 3), 4-(4-hydroxyphenyl)- 3-methyl-1-phenyl-4, 6-dihydro- pyrazolo [3', 4':5,6]pyrano[2,3-d]pyrimidine-5-imine (compound 4) and N-[4-(4-hydroxyphenyl)- 3-methyl-1-phenyl-7-thioxo-7,8- dihydropyrazolo [3', 4':5,6] pyrano [2,3-d] pyrimidine-5-yl] thiourea (compound 5) respectively. Moreover a series of Schiff bases 6(a-f) were prepared by reaction of compound 2 with different aromatic aldehydes.
The prepared compounds were characterized by FTIR, and most 1HNMR,13CNMR and evaluated as antioxidant additives by blending 1% of each compound with base lubricating oil 60 stock supplied by Midland Refineries Company, Baghdad, Iraq. The formulated blend of compound 6a showed better oxidation stability compared with the base oil (blank), while the oil blend of compound 5 gave higher oxidation stability than the blend with standard antioxidant supplied by Midland Refineries Company.
Synthesis, Characterization and Evaluation of Some Pyranopyrazoles and Pyranopyrimidines Derivatives as Antioxidants for Lubricating Oils
Pyranopyrazol
Pyranopyrimidine
Schiff base
Microwave
Lubricating oil
Antioxidant.
Publication Date
Tue Jan 18 2022
Journal Name
Materials Science Forum
The Effect of Gamma Radiation on the Manufactured HgBa<sub>2</sub>Ca<sub>2</sub>Cu<sub>2.4</sub>Ag<sub>0.6</sub>O<sub>8+δ</sub> Compound
Gamma doses radiation
crystal size
strain
degree of crystallinity
Scherrer
crystallinity and Williamson equations.
In this article four samples of HgBa2Ca2Cu2.4Ag0.6O8+δ were prepared and irradiated with different doses of gamma radiation 6, 8 and 10 Mrad. The effects of gamma irradiation on structure of HgBa2Ca2Cu2.4Ag0.6O8+δ samples were characterized using X-ray diffraction. It was concluded that there effect on structure by gamma irradiation. Scherrer, crystallization, and Williamson equations were applied based on the X-ray diffraction diagram and for all gamma doses, to calculate crystal size, strain, and degree of crystallinity. I
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