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New N-heterocylic, homocyclic and aliphatic dronic acids were synthesized through an improved facile and versatile route by the reaction of various carboxylic acids with Phosphorus trichloride (PC), phosphorus acid (PA) and methanesulfonic acid under reflux and inert atmosphere. Representatively, the dronic acid derived from stearic acid as a long chained fatty acid was also synthesized. All the obtained compounds were analyzed and characterized by means of FT IR, 1H, 13C and 31P NMR spectroscopic techniques. In addition, the compound derived from stearic acid was characterized by means of FT IR and Mass spectrometry due to its insolubility in D2O and DMSO-d6. [ABSTRACT FROM AUTHOR]

A facile and efficient method for one-pot synthesis of N-alkyl sulfonamides from alcohols using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this protocol, treatment of various potassium sulfonylamide salts and alcohols in the presence of TsIm and triethylamine in refluxing DMF furnishes the corresponding N-alkyl sulfonamides in good to excellent yields. This methodology is highly efficient for reaction of various structurally diverse primary and secondary alcohols as well as potassium sulfonylamides. Also, the density functional theoretical calculations are employed to mechanistically study this protocol. [Supplementary materials are available for this article. Go to the publisher's online edition ofPhosphorus, Sulfur, and Silicon and the Related Elementsfor the following free supplemental files: Additional text and figures.] [ABSTRACT FROM AUTHOR]

[image omitted] A highly efficient procedure for etherification and oxidation of aromatic alcohol is described using unsupported and supported P2O5 on alumina and/or silica gel. The silica gel and alumina proved to be the most suitable support among the supports examined in our experiments. It was illustrated that the etherification and oxidative performance in reactions depend largely upon variables including reaction temperature, the nature of the P2O5 used (supported or unsupported P2O5), and whether solvent-free conditions are applied. It was shown that P2O5 not only can convert the aromatic alcohols into corresponding ethers and/or aldehyde and ketone but also can convert aromatic ethers into aldehyde or ketone via oxidative cleavage. Finally, quantum mechanical calculations were performed to rationalized these events, and it was indicated that aldehyde and ketone are more favorable products on the basis of the heat of formation (ΔHf). [ABSTRACT FROM AUTHOR]

Purine and pyrimidine nucleobases and other N-heterocycles have been silylated with HMDS in excellent yields in the presence of a catalytic amount of silica sulfuric acid (SSA) as a heterogeneous catalyst. SSA utilizes a shorter reaction time and higher yields of silylated nucleobases. SSA is reusable for several times without a decrease in reactivity or yield of silylated adducts. [ABSTRACT FROM AUTHOR]

A facile and efficient method for dehydration of aldoximes into nitriles using N-(p-toluenesulfonyl) imidazole (TsIm) is described. In this method, aldoximes were refluxed with TsIm in the presence of 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU) in dimethylformamide (DMF) to afford the corresponding nitriles in good yields. This methodology is highly efficient for various structurally diverse aldoximes including aromatic, heteroaromatic, and aliphatic oximes. A plausible mechanism for the conversion of aldoxime into nitriles using TsIm/DBU is explained. [ABSTRACT FROM AUTHOR]

A facile and highly efficient method for one-pot Beckmann rearrangement of ketoximes into N-substituted amides using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, ketoximes are refluxed with TsIm and Cs2CO3 in the presence of SiO2 as a recyclable catalyst in DMF affording the corresponding amides in high yields. This methodology is highly efficient and regioselective for various structurally diverse ketoximes including symmetrical and unsymmetrical as well as cyclic oximes. The results of quantum mechanical studies used to rationalize the experimental outcomes are discussed. [ABSTRACT FROM AUTHOR]