Aromatic dialdehydes were synthesized from 5-t-butylsalicylaldehyde and o-vanilline in good yields using paraformaldehyde, hydrobromic acid and catalytic amounts of sulfuric acid in one step which was previously unavailable with present methods. Key Words: aromatic dialdehydes, bromomethylation, 5-t-butylsalicylaldehyde, o-vanilline. 

A highly efficient synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones in 2-ethylhexanoic acid as green, low cost and recoverable catalytic medium, illustrates good synthetic utility of this method.  Key Words:  2-ethylhexanoic acid, 3,4-dihydropyrimidin-2(1H)-ones/thiones, organocatalyst. 

In this paper, we obtain a common coincidence point theorem for  two pairs of hybrid functions on cone metric spaces. Key words: Cone metric spaces,coincidence points, multi functions.2000 Mathematics Subject Classification : 47H10,54H25.

The sequential extraction procedure of Zinc and lead performed in a Brazilian soil showed that it presents high pollution potential once over 90% of total lead is present in fractions where the metals can be easily mobilized. The fraction contents…

A potentiometric zirconium sensor based on the use of 4-nitrophenylazo-N-(2-hydroxypropylamine)salicylidine (NHPS) as an ion carrier in poly (vinyl chloride) (PVC) matrix, was developed. The best performance was observed for the membrane composition including 26.27% PVC, 65.67% N-POE, 5.43% NaTPB and…

A Fourier transform infrared (FT-IR) spectrometric method was developed for the rapid, direct measurement of oseltamivir phosphate (OP) in pharmaceutical formulations. Conventional KBr-spectra were compared for best determination of the active substance in pharmaceutical preparations. The Beer-Lambert law and two…

In this study, a solid phase extraction method has been developed for the preconcentration of Zn(II) at trace level using β-cyclodextrin polymer modified with 1-(2-Pyridylazo)-2-Naphthol (PAN) reagent. After preconcentration, metal retained on the polymer was eluted with 5.0 mL of…

In this study, we studied the complete lift of almost product, almost complex, almost contact and almost paracontact structures on a given manifold  to vector subbundle  of vector bundle . Moreover, we studied a correspondence between the integrability conditions of…

In this study, commands written on the basis of Uniform Confidence Bands (UCB) in the new windows version of the XploRe package for testing the validity of the link function assumed for binary parametric complementary log log model were introduced.…

Multilevel inverters have become more popular due to reduced switching losses, low costs, low harmonic distortion and high-voltage capability when compared to traditional PWM inverters. A new family of multilevel inverters that has decreased the number of separated DC sources…