Y. V. Rami Reddy

Microwave-assisted facile synthesis of trisubstituted pyrrole derivatives

Abstract We report efficient synthesis of pyrrole derivatives by use of microwave irradiation. Quantitative yields were obtained in short reaction times. Low yields of product were obtained from alicyclic amino unsaturated ketone derivatives; higher yields were obtained from aliphatic amino unsaturated ketone derivatives.Graphical Abstract

Electrochemical Reduction Behavior Of Mephedrone Drug At A Dropping Mercury Electrode And Its Pharmaceutical Determination In Spiked Human Urine Samples

The designer drug 1-(4-methylphenyl)-2-methylaminopropan-1-one (4-methylmethcathinone or mephedrone) is reported to possess psychostimulant, entactogenic and hallucinogenic effects. From the structural point of view mephedrone drug has keto (-C=O) functional group. In the present paper, we have reported the reduction behavior of mephedrone was studied on the surface of the dropping mercury electrode (DME) as working electrode in universal buffer of pH range from 2.0 to 12.0 by direct current polarography, differential pulse polarography, cyclic voltammetry and controlled potential electrolysis. Mephedrone showed one reduction peak and the results indicated that the reduction processes of mephedrone is irreversible and was diffusion controlled as evidence from linear plots of id against h1/2. Millicoulometric experiment was performed successfully in estimating the number of electrons and protons involved in the reduction processes and to understand reduction mechanism. Kinetic parameters such as diffusion co-efficient (D) and heterogeneous forward rate constant (Kof, h) are evaluated and reported. Quantitative measurements were successful in the concentration range 1.0 × 10-5 to 1.5 × 10-9 M with lower detection limit 1.25 × 10-8 M. INTRODUCTION: The designer stimulant 4-methylmethcathinone (4-MMC) (Mephedrone) is a β-ketoamphetamine (1-(4-methylphenyl)2-methylaminopropan-1-one) and is among the most popular of the derivatives of naturally occurring psychostimulant cathinone and substituted amphetamines. Mephedrone is one of hundreds of designer drugs that have been reported in recent years, including artificial chemicals such as synthetic cannabis and semi synthetic substances such as methylhexaneamine. These drugs are primarily developed to avoid being controlled by laws against illegal drugs, thus giving them the label of designer drugs [1]. According to the European Monitoring Centre for Drugs and Drugs Addiction, the synthesis of mephedrone was first reported in 1922 by Saem de Bumaga Sanchez in the Bulletin de la Societe Chemique de France, under the name toluyl-alpha-monomethylaminoethylcetone. Abuse of mephedrone has increased dramatically as well as producing the intended stimulant effect, negative side effects occurs when mephedrone used and has become a significant public health problem in the United States and European countries. A drug similar to mephedrone, containing cathinone, was sold legally in Israel from around 2004, under the name hagigat. When this was made illegal, the cathinone was modified and the new products were sold by the Israeli company, Neorganics [2-4]. The products had names such as Neodoves pills, but the range was discontinued in January 2008 after the Israeli government made mephedrone illegal [5-7]. The metabolism of mephedrone has been studied in rats and humans and the metabolites can be detected in urine after usage. Nothing is known about its potential neurotoxicity but scientist have studied and suggested possible dangers associated with its use based on its similarity to other drugs. Several deaths the media attributed to the drug were later determined to have been caused by other factors. Owing largely to its recent emergence, there is no formal pharmacodynamic or pharmacokinetic studies of mephedrone but very little information is available on neurochemical action of mephedrone. Figure 1. Some biologically active mephedrone like molecules In recent years the electrochemical techniques have led to the advancement in the field of analysis because of their sensitivity, low cost and relatively short analysis time when compared to other techniques. Additional application of electroanalytical techniques includes the determination of reaction mechanisms. Redox properties of a drug can give insight into its metabolic fate or its in vivo redox processes or pharmaceutical activity [810]. Critical literature survey revealed that no attempt has been made to investigate the electrochemical behavior of mephedrone hydrogen chloride and its pharmaceutical determination in spiked urine samples. Based on over view, we have developed a simple and prompted electrochemical method for assay of mephedrone hydrogen chloride. The present work includes the reduction behavior of mephedrone hydrogen chloride at dropping mercury electrode and development of a DPP method for its determination in pharmaceutical formulations as well as suggested the mechanism of reduction processes. NH2 O NH2

Sequential oxonium–olefin–alkyne cyclization for the stereoselective synthesis of (octahydro-1H-pyrano[3,4-c]pyridin-5-yl)methanone derivatives

A broad range of aldehydes undergo a smooth cascade cyclization with (E)-5-(3-phenylprop-2-ynylamino)pent-3-en-1-ol in the presence of BF3·OEt2 at room temperature to furnish a novel series of (octahydro-1H-pyrano[3,4-c]pyridin-5-yl)methanone derivatives in good yields and diastereoselectivities. This cascade process provides a simple and proficient alternative for the stereoselective construction of fused pyranopiperidine derivatives.

Sensitive Spectrophotometric Method for the Determination of Niguldipine in Pharmaceutical Formulations

Simple, sensitive and rapid spectrophotometric methods were developed for the determination of Niguldi- pine in pharmaceutical formulations. Method A was based on the extractive spectrophotometry and the devel- oped color complex due to the formation ion association complex with Bromothymol blue (BTB) at pH 3.7. The formation of a yellow color solution exhibited maximum absorption at wavelength 380 nm. Method B was based on the yellow color formation due to ion association complex between methyl orange (MO) and Niguldipine at PH 3.7 that exhibited maximum absorption at a wave length of 430 nm. Both ion association complexes were extracted into chloroform and Beers law was obeyed over the concentration ranges 4-25 µgml-1 and 2-12 µgml-1 for methods A and B respectively. Both the methods have been successfully applied for the assay of the drug in pharmaceutical formulations. No interference was observed from common pharmaceutical adjuvants. The reliability and the performance of the proposed methods were established by point and interval hypothesis tests through recovery studies.