Minimizing of power loss in Li-Cd ferrite by nickel substitution for power applications

The effect of Ni substitution on the microstructure, dielectric, impedance, magnetic and power loss properties has been investigated on a series of Li_0.35-0.5xCd_0.3Ni_xFe_2.35-0.5xO₄ (0.00≤x≤0.08) ferrite prepared by citrate precursor method. Dielectric and impedance measurements have been determined in the frequency range 100 Hz-10 MHz. An enhancement in permittivity was observed with Ni concentration and exhibits the maximum value of ∼7×10³ for x=0.02 sample. The impedance spectroscopy technique has been used to study the effect of grain and grain boundary on the electrical properties of all the samples. Power loss measurements have been carried out in the frequency range 50 kHz-5 MHz at induction condition of B=10 mT. Power loss has been found to be quite low, less than 100 kW/m³ up to 500 kHz, with the substitution of Ni in Li_0.35-0.5xCd_0.3Ni_xFe_2.35-0.5xO₄ ferrite, which is useful for technological aspects.     

Synthesis, determination of absolute configuration, and biological evaluation of spiro-fused thiadiazoline inhibitors of kinesin spindle protein (KSP)

A facile and highly convergent synthesis of biologically active spiro-fused thiadiazoline KSP inhibitors is reported. The highlights of the synthesis include the Michael reaction and cyclization of thiosemicarbazone to 1,3,4-thiadiazoline. This chemistry lends itself to the preparation of (+)-2, a potent and orally bioavailable anti-cancer agent, and to the development of a structure-activity relationship program.     

Preparation, structure and spasmolytic activities of some derivatives of harmine series of alkaloids

Keeping in view the interesting chemistry and pharmacological importance of harmine series of bases -- the beta-carboline alkaloids, a number of new derivatives of tetrahydroharmine and harmalol have been prepared and characterized through spectral studies. Some of these derivatives showed spasmolytic activity. It was observed that all the N-acyl tetrahydroharmine derivatives are stable, not labile and no ring opening occurs in these compounds, as reported recently.     

Simultaneous Determination of Paracetamol and Orphenadrine Citrate in Dosage Formulations and in Human Serum by RP‐HPLC

Rapid liquid chromatographic procedures are proposed for analysis of paracetamol and orphenadrine citrate in pharmaceutical preparations and human serum using acetonitrile: water (50:50) as a mobile phase, adjusting pH to 2.6, UV detection at 215 nm and propylparaben sodium as internal standard. The advantages of this method include good and rapid separation, well resolved peaks, and only a small amount of sample is required for assay and adequate precision. The method showed good linearity in the range of 6 to 10000 ng/mL for paracetamol serum concentrations with a correlation coefficient 0.9999 (inter and intra day CV < 3.15) and in the range 3–10000 ng/mL for orphenadrine citrate serum concentrations with a correlation coefficient of 0.9999 (inter and intra day CV < 3.58). The recovery of paracetamol and orphenadrine citrate was > 96.9% and > 96.7%, respectively. The proposed method may be used for the quantitative analysis of paracetamol and orphenadrine citrate alone or in combination from raw materials, in bulk drugs, dosage formulations and in serum.     

Synthesis and Antimicrobial Studies of Some Quinolinylpyrimidine Derivatives

The quinolinylpyrimidine derivatives were prepared by the condensation of quinolinyl chalcones with urea (or thiourea) under basic conditions by using both conventional and microwave heating. Their IR, ¹H NMR, ¹³C NMR, mass spectra and CHN analyses confirmed the prepared compounds. The newly prepared quinolinylpyrimidine derivatives were screened for antimicrobial activities against the bacterial strains viz. S. aureus, Shigella, Salmonela, P. aeroginosa, B. Subtilus and E. coli and found considerably active against S. aureus, P. aeroginosa and E. coli.     

Arylations mediated by lead(IV) in the presence of formazan and imine ligands

The use of formazan and imine ligands in arylations of β-dicarbonyl systems by phenyl boronic acid/lead(IV) carboxylates is examined.     

Dimethyl telluride as a ligand: synthesis and physicochemical studies on its complexes with transition metal bis(chlorosulphates) M(SO3Cl)2(M=Cr,Mn, Fe,Co, Ni,Cu)

Summary Dimethyl telluride, Me₂Te, reacts with first row transition metal bis(chlorosulphates), M(SO₃Cl)₂(M=Cr^II, Mn^II, Fe^II, Co^II, Ni^II, Cu^II) in MeCN resulting in the formation of compounds of the type [M(SO₃Cl)₂-(Me₂Te)₂]. These compounds are stable under N₂ but decompose on exposure to moist air. The covalent nature of bonding of the SO₃Cl^– group has been ascertained on the basis of a positive shift in ₁ (A) vibration, splitting of the doubly degenerate (E) modes and low molar conductivity values. The magnetic moments and electronic spectra suggest an octahedral geometry for these compounds (except for the Ni^II complex where a tetragonal distortion is observed) where each SO₃Cl^– group is bonded in a bidentate manner.     

Heterocyclic steroids: Synthesis of androsteno[17,16-d]pyrazoles and androsteno[17,16-e]pyrimidines

The Vilsmeier-Haack reaction of 3β-acetoxyandost-5-en-17-one ( 1 ) with phosporous oxychloride and dimethylformamide gave 3β-acetoxy-17-chloro-16-formylandrosta-5,16-diene ( 2 ). Reaction of 2 with hydrazine and phenylhydrazine provided substituted 5-androsteno[17,16-d]pyrazoles 3 and 4 respectively. Similarly, condensation of 2 with urea and guanidine hydrochloride revealed the formation of the corresponding substituted pyrimidines 5 and 6 respectively.