Synthesis and reactions of 3-aminotetrachloroquinazolin-2,4-dione

N-phenylsulphonyloxytetrachlorophthalimide was obtained by treatment of N-hydroxy tetrachlorophthalimide with benzenesulphonyl chloride. Also, the titled compound 3 was obtained by reaction of compound 2 with hydrazine hydrate via Lossen rearrangement. Compound 3 used as starting material for the synthesis of new pyrimidine and quinazolinedione derivatives containing four chlorine atoms which have pharmacological activity

Utility of (2,4-dioxo-1,4-dihydro-2H-quinazolin-3-yl)-acetic acid hydrazide in the synthesis of some heterocyclic nitrogen compounds

An efficient synthesis of (2,4-dioxo-1,4-dihydro-2H-quinazolin-3-yl)-acetic acid hydrazide (3) has been achieved and described. The obtained hydrazide (3) was used in building of some interesting heterocycles such as, triazole, oxadiazole, pyrazole, phthalazine, and indol-2-one rings at position 3. The structures of the obtained compounds were confirmed by IR, 1H NMR, 13C NMR, MS spectral and elemental analysis

2D finite element analysis and force calculations for induction motors with broken bars

AbstractIn this paper an ABC transient model of the three phase induction motor is developed that depends on self- and mutual inductance calculations based on accurate finite element analysis (FEA). This model can represent both healthy and broken bars’ conditions. The effects of that type of fault on the stator current, rotor bar currents distribution, the forces exerted on the rotor bars, the motor speed and motor torque are studied. It was observed that broken bar faults will cause fluctuations in the stator peak current and in the motor speed and torque. It was found that the asymmetry in the rotor bar currents will lead to asymmetrical distribution of the radial and tangential forces affecting the bars. The asymmetry in the tangential forces causes the fluctuations in the motor torque, while the asymmetry in the radial forces will increase the mechanical stresses on the rotor shaft

Synthesis and spectral characterization of some heterocyclic nitrogen compounds

Quinazolines and pyrimidines are most important class of compounds and have received much attention from both synthetic and medicinal chemists, because of the diverse range of their pharmacological properties. Owing to their versatile chemotherapeutic importance, a number of quinazolin-2,4-dione derivatives were synthesized using appropriate synthetic routes and characterized by IR, 1H NMR, MS, and elemental analysis

Synthesis, Structural, and Theoretical Studies of Quinazoline-2,4-dione Derivatives

<p>New quinazolin-2,4-dione derivatives have been synthesized and fully characterized. The new derivatives were synthesized using 3-(2-imino-4-oxo-3H,4H,5H-thiazolidin-3-yl)-1H-quinazolin-2,4-dione by nucleophilic addition mechanism. DFT calculations using B3LYP/6–311++G(d,p) level of the theory were used to investigate the molecular structures and the relative stabilities of the anticipated isomers (E and Z). Both experimental and theoretical calculations confirmed the higher stability of the Z-isomers compared to the E-isomers. The former is stabilized by two intramolecular hydrogen bonds compared to only one in the latter isomer. The frontier orbital calculations (HOMO and LUMO), and the energy gap confirmed the stability of the molecules.</p

Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality