02167nas a2200241 4500008004100000022001400041245012000055210006900175260007300244300001200317490000800329520127700337653001801614653002401632653001301656653002201669653001901691653001401710100002101724700002501745700002901770856012601799 2009 eng d a1381-116900aHydroesterification of 2-vinyl-6-methoxynaphthalene using palladium complexes containing chelating nitrogen ligands0 aHydroesterification of 2vinyl6methoxynaphthalene using palladium aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL a134-1410 v3073 a

Hydroesterification of 2-vinyl-6-methoxynaphthalene (VMN) to methyl ester of 6-methoxy naphthyl propionic acid (ester of naproxen) has been investigated using palladium complexes containing the chelating N(boolean AND)O and N(boolean AND)N ligands (pyridine-2-carboxylate, 2-acetylpyridine, 2-pyridine-carboxaldehyde, and bipyridine) as catalysts. Palladium complex containing 2-acetylpyridine as the ligand was found to be superior to other Pd-complexes. Both acid and halide promoters were necessary for high activity and selectivity. As an acid promoter, benzenesulfonic acid was found to be more effective compared to p-toluenesulfonic acid. Formation of ether 2-methoxy-6-(1-methoxyethyl)naphthalene and a polymer of VMN was observed in all the reactions. It was observed that active catalytic species generated during carbonylation reaction was responsible for the polymer formation. The effect of various parameters such as solvents, CO pressure, and alcohols on the catalytic activity as well as the selectivity was investigated. The turnover frequency using the complex Pd(acpy)(PPh(3))(OTs)(2) (acpy = 2-acetylpyridine) catalyst was found to be 42 h(-1), which is the highest for the hydroesterification of VMN. (C) 2009 Elsevier B.V. All rights reserved.

10aCarbonylation10aHydroesterification10aNaproxen10aPalladium complex10aPolymer of VMN10aPromoters1 aAtla, Shashi, B.1 aKelkar, Ashutosh, A.1 aChaudhari, Raghunath, V. uhttp://library.ncl.res.in/content/hydroesterification-2-vinyl-6-methoxynaphthalene-using-palladium-complexes-containing-002602nas a2200265 4500008004100000022001400041245010800055210006900163260007100232300001200303490000600315520165100321653001301972653002301985653001902008653001902027653001302046653002802059100002302087700002302110700002102133700002702154700002402181856013102205 2012 eng d a1543-838400aProbing influence of mesophasic transformation on performance of self-emulsifying system: effect of ion0 aProbing influence of mesophasic transformation on performance of a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB a318-3240 v93 a

Self-emulsifying systems are mixtures of oils and surfactants, ideally isotropic, sometimes including cosolvents, which emulsify under conditions of gentle agitation, similar to those which would be encountered in the gastrointestinal tract. The process of self-emulsification has remained the center of attraction for most researchers. Controlled hydration of self-emulsifying systems shows formation of an intermediate gel phase which upon rupture forms an emulsion. Current work was undertaken to understand and explore the microstructural properties of intermediate gel phase which are believed to influence the performance (droplet size) of the final formulation. The effect of additives on microstructural properties of intermediate gel phase has also been investigated. Microstructural elucidation of hydrated samples of intermediate regimes was done by using techniques such as small angle X-ray scattering, differential scanning calorimetry and rheology. Samples from intermediate regimes showed formation of local lamellar structure which swelled with hydration. In the present work, the effect of addition of salt form of naproxen (sodium and potassium) and naproxen (base) on microstructural properties of intermediate regimes was investigated. Systems containing naproxen salts formed larger droplets whereas naproxen base formed smaller ones. Microstructural properties of intermediate lamellar structures were well correlated with performance of the final formulation. The current studies indicate that by controlling the properties of intermediate regimes optimized formulations with desired performance can be tailor-made.

10aemulsion10alamellar structure10aliquid crystal10aMicrostructure10aNaproxen10aself-emulsifying system1 aPatil, Sharvil, S.1 aVenugopal, Edakkal1 aBhat, Suresh, K.1 aMahadik, Kakasaheb, R.1 aParadkar, Anant, R. uhttp://library.ncl.res.in/content/probing-influence-mesophasic-transformation-performance-self-emulsifying-system-effect-ion-001634nas a2200265 4500008004100000022001400041245010100055210006900156260007300225300001000298490000800308520069500316653001401011653001301025653002501038653001501063653001401078653002201092100002901114700002701143700002401170700001901194700002401213856013101237 2014 eng d a0926-860X00aRegioselective acylation of 2-methoxy naphthalene catalyzed by supported 12-phosphotungstic acid0 aRegioselective acylation of 2methoxy naphthalene catalyzed by su aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP a55-610 v4863 a

12-Phosphotungstic acid supported on silica gel, zirconium sulfate, and a combination of silica gel and zirconium sulfate (50% w/w) were employed as solid acid catalysts for regioselective acylation of 2-methoxynaphtalene with acetic anhydride. 1-(6-Methoxynaphthalen-2-yl)ethanone (2,6-AMN), a commercially important intermediate for production of Naproxen, was obtained with excellent selectivity (>98%) at 67-68% conversion using 12-phosphotungstic acid supported on silica gel 20% (w/w) in refluxing tetrachloroethane. The unreacted starting material can be easily separated from the product by a simple crystallization from nonane. (C) 2014 Elsevier B.V. All rights reserved.

10aAcylation10aNaproxen10aPhosphotungstic acid10aSilica gel10aSupported10aZirconium sulfate1 aKumaraguru, Thenkrishnan1 aDevi, Ayala, Vedamayee1 aSiddaiah, Vidavalur1 aRajdeo, Kishor1 aFadnavis, Nitin, W. uhttp://library.ncl.res.in/content/regioselective-acylation-2-methoxy-naphthalene-catalyzed-supported-12-phosphotungstic-acid-0