Intermolecular Dipole–Dipole Relaxation of Xe Dissolved in Water

Intermolecular ¹²⁹Xe–¹H nuclear Overhauser effects and ¹²⁹Xe longitudinal relaxation time measurements were used to demonstrate that the dipole–dipole coupling is the dominant relaxation mechanism for ¹²⁹Xe in water, at room temperature. ¹²⁹Xe–¹H cross-relaxation rates were derived to be ς_XeH 3.2 ± 0.3 × 10⁻³ s⁻¹, independent of xenon pressure (in the range of 1–10 bar) and of the presence of oxygen. Corresponding xenon–proton internuclear distances were calculated to be 2.69 ± 0.12 Å. Using the magnitude of the dipole–dipole coupling and the spin density ratio between dissolved xenon and bulk water, it is estimated that ¹²⁹Xe–¹H spin polarization-induced nuclear Overhauser effects would yield little net proton signal enhancement in water.     

Chemoselective Reduction of Carbonyl Compounds with PMHS - ZnCl2

An inexpensive and safer reagent system comprising of PMHS and ZnCl₂ has been developed for the selective reduction of carbonyl compounds to corresponding alcohols.

     

Synthesis and Spectral Characterization of Related Substances of Lacidipine,an Antihypertensive Drug

Five related substances (impurities) were detected in lacidipine bulk drug substance by a simple high-performance liquid chromatographic method (HPLC) and were identified by liquid chromatography–mass spectrometry (LC-MS). These related substances were independently synthesized, characterized, and co-injected with the sample containing impurities.     

A Short,Efficient and Stereos Elective Synthesis of (±)-Recifeiolide

The synthesis of macrolides¹ is currently under intensive investigations because of their diverse biological and physiological activities. The recent developments in their synthetic strategies made the task easier for synthesis of several naturally occurring rnacrolides.     

A Facile Synthesis of 3,7-Diphenyl-4,8-distyryl-2,6-dioxo-2H,6H-benzo[1,2-b:3,4-b′] Dipyrans and Their Antifeedant Activity.

The synthesis, characterisation and antifeedant activity of some new angular dicoumarins prepared from 2,4-diacetyl resorcinol has been reported.     

Lansoprazole,an antiulcerative drug

Lansoprazole, 2‐({[3‐methyl‐4‐(2,2,2‐trifluroethoxy)­pyri­din‐2‐yl]­methyl}­sulfinyl)‐1H‐benz­imidazole, C₁₆H₁₄F₃N₃O₂S, is an antiulcerative agent. The mol­ecules in the lattice are held together by intermolecular hydrogen bonds between the NH group of benz­imidazole and the sulfinyl O atom.     

Novel methodologies for the synthesis of functionalized lipophilic carboranes

Novel synthetic protocols for the synthesis of lipophilic carboranes were developed utilizing two C? C bond forming reactions, namely Baylis–Hillman and enynedioate cycloaddition reactions. Some of these carboranes were converted into further functionalized carboranes via nucleophilic allylic isomerization. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis of R(+)-α-Lipoic Acid

An efficient enantiospecific synthesis of R(+)-α-Lipoic acid (1) a prosthetic group and a vital cofactor in -α-keto acids decarboxylation is described.