A highly efficient and mild protocol for the aminocarbonylation of a nucleoside is developed by employing palladium/(1,3,5-triaza-7-phosphaadamantan-1-ium-1-yl)butane-1-sulfonate (Pd/PTABS) as the catalytic system. The developed aminocarbonylation methodology employs CO gas at a relatively low temperature of 60 °C and is suitable for a wide range of amines, including (heteroaryl)benzylic, aliphatic acyclic, alicyclic and secondary amines. This protocol is also utilized for the synthesis of a sangivamycin precursor by carrying out the Pd-catalyzed amination and aminocarbonylation simultaneously. The utility of this protocol is further demonstrated by the synthesis of the drugs moclobemide and nikethamide.

The osmotic coefficient measurements for binary aqueous solutions of 2,2,2-cryptand (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8] hexacosane) in the concentration range of ~0.009 to ~0.24 mol·kg(-1) and in ternary aqueous solutions containing a fixed concentration of 2,2,2-cryptand of ~0.1 mol·kg(-1) with varying concentration of KBr (~0.06 to ~0.16 mol·kg(-1)) have been reported at 298.15 K. The diamine gets hydrolyzed in aqueous solutions and needs proper approach to obtain meaningful thermodynamic properties. The measured osmotic coefficient values are corrected for hydrolysis and are used to determine the solvent activity and mean ionic activity coefficients of solute as a function of concentration. Strong ion-pair formation is observed, and the ion-pair dissociation constant for the species [CrptH](+)[OH(-)] is reported. The excess and mixing thermodynamic properties (Gibbs free energy, enthalpy, and entropy changes) have been obtained using the activity data from this study and the heat data reported in the literature. Further, the data are utilized to compute the partial molal entropies of solvent and solute at finite as well as infinite dilution of 2,2,2-cryptand in water. The concentration dependent non-linear enthalpy-entropy compensation effect has been observed for the studied system, and the compensation temperature along with entropic parameter are reported. Using solute activity coefficient data in ternary solutions, the transfer Gibbs free energies for transfer of the cryptand from water to aqueous KBr as well as transfer of KBr from water to aqueous cryptand were obtained and utilized to obtain the salting constant (ks) and thermodynamic equilibrium constant (log K) values for the complex (2,2,2-cryptand:K(+)) at 298.15 K. The value of log K = 5.8 ± 0.1 obtained in this work is found to be in good agreement with that reported by Lehn and Sauvage. The standard molar entropy for complexation is also estimated for the 2,2,2-cryptand-KBr complex in aqueous medium.

Review covering the synthesis of 5- and 6-membered as well as condensed heteroarenes, focussing on the combinations in cooperative catalytic systems in strategies used to achieve selectivity and also highlights the mode of action for the cooperative catalysis leading to the synthesis of commercially and biologically relevant heteroarenes.

Herein, we reported our studies related to structural elucidation and gas-phase fragmentation patterns of the imidazolium and pyridinium based ionic liquids, using a positive ion electrospray ionization triple quadrupole mass spectrometry. Ionic liquids mainly imidazolium/ pyridinium/alkylammonium salts, possess properties due to which there are many applications from the point of view of green chemistry. The recorded mass spectral patterns are presented and possible pathways for fragmentations are suggested. The mass spectrum of tetrabutylammonium bromide and its fragmentation pattern is discussed since we used this compound as a template in the synthesis of ionic liquids. Our analysis also suggests possibilities of associations of ions in the form of C2A + species in vapour phase for the studied ionic liquids.

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Aniline was polymerized under different experimental conditions such as interfacial polymerization, rapid mixing in hydrochloric acid medium and classical bulk polymerization method using p-toluene sulphonic acid. The resulting polyanilines were characterized by infrared, X-ray diffraction, conductance and scanning electron microscopic analysis. The main emphasis of the paper is to study the thermal response of the synthesized polyanilines by thermogravimetric analysis and differential scanning calorimetry (DSC). The DSC data were utilized further to calculate the specific heat capacities of the synthesized polyanilines as a function of temperature.

Reliance Industries Limited operates D1D3 deep water gas field in Krishna-Godavari basin in India. Water depth at well heads varies from 550 meter to 1150 meter. Horizontal Christmas trees (XMT) are installed on each well head. Hydrate inhibitor is continuously injected at Christmas tree to prevent hydrate formation occurring in the system during all operating conditions. For a properly designed system, hydrate formation should not be possible in normal operation. The only risk of hydrate formation is related to abnormal operating conditions. Hydrate management philosophy should be developed to address the risk of hydrate formation in all condition with minimum hydrate inhibitor injection. There are always some uncertainties in measurements therefore some level of hydrate inhibitor overdosing is required. In this field Mono Ethylene Glycol (MEG) is injected to prevent hydrate formation. To optimize MEG injection, reliable water and MEG measurements are the important keys. Salinity of slug, pipeline network and different well head water depths are major driving factors to optimize MEG injection. Hydrate curve is developed either with professional software like PVTsim or rocking cell apparatus in laboratory. In this field minimum required MEG percentage is calculated from PVTsim software. MEG optimization is continuous process and since inception of field, the level of overdosing is reduced from 80% to 15%. Wet Gas Flow Meter (WGFM) is installed on each XMT to measure water production. To verify WGFM water measurement from individual well, other methods of measurement were also developed. MEG injection valves are installed on each XMT which can measure the injection quantity. Correlation is established between different measurement techniques to consider most reliable and accurate value of water and MEG measurement which aided to optimize the MEG injection rates. Analysis is done through software for some of wells, to find out the feasibility to stop continuous MEG injection in deep water pipeline network system. After this study, continuous MEG injection was stopped in one well. The paper will describe various steps of MEG optimization and level of confidence on hydrate management philosophy.