Facile Conversion of Aryl Amines Having No α-Methylene to Aryl Nitriles.

Dimethyl carbonimidodithioates, 2 derived from various primary aryl amines (1) by reacting with carbon disulfide and methyl iodide in dimethyl formamide in the presence of concentrated sodium hydroxide, are converted to the diaziridine derivatives, 3 by reacting with hydrazine in ethanol. The diaziridines, 3 on oxidation with lead tetraacetate in refluxing xylene, extrudes nitrogen, and intramolecular stabilization, particularly 1,2-carbon migration, takes place to give the product, 5. The reaction may take place through the intermediates, diazirines, 4, which have not been isolated. This work provides a new approach for the conversion of aryl amines having no α-methylene to aryl nitriles.

Diacetoxyiodobenzene assisted C-O bond formation via sequential acylation and deacylation process: synthesis of benzoxazole amides and their mechanistic study by DFT.

An efficient method for the transformation of N-substituted-N'-benzoylthioureas to substituted N-benzoxazol-2-yl-amides using diacetoxyiodobenzene (DIB) is described in this work. The transformation follows the C-O bond formation leading to the benzoxazole derivative, due to oxidative dehydrogenation by DIB, instead of the expected C-S bond formation of the benzothiazole moiety. The C-O bond formation leading to benzoxazole is due to consecutive acylation and deacylation in conjunction with the reduction of two moles of DIB. A plausible mechanism was proposed for the reaction and density functional calculations were also performed to study the reaction mechanism.

Studies on the chemical constituents and antioxidant activities of extracts from the roots of Smilax lanceaefolia Roxb.

A flavonol glycoside (1) and a steroidal saponin (2), along with beta-sitosterol and beta-sitosterol-D-glucoside, were isolated from the roots of Smilax lanceaefolia Roxb. Mineral contents were determined using the atomic absorption spectrophotometer and the total antioxidant activity was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging method.

Synthesis of some A- and D-ring fused steroidal pyrazoles, isoxazoles and pyrimidines.

The preparation of steroidal heterocycles containing pyrazole, isoxazole and pyrimidine rings fused to the 2,3- and 16,17-positions of the steroid nucleus is described. These were prepared by the reaction of hydrazine, hydroxylamine and guanidine, respectively, with 2-ethoxymethylene-3-oxo- or 16-ethoxymethylene-17-oxo- or 2-bis(methylthio)methylene-3-oxo- or 16-bis(methylthio)methylene-17-oxo-steroids.