a spectrophotometric study concerning the interactoin between iodine and bromine with tetrabutylammonium iodide (tbai), tetrabutyl- ammonium bromide (tbabr) and cryptand 222 (c222) has been performed in dichloromethane solution at 25°c. the results are indicative of the formation of tba+x3- and  c222x+x3-  through equilibrium and formation of c222x+x-  through nonequilibrium reactions. the stab...

A new, high yielding method for the preparation of vasicinone (7) is described. Reaction of 2-nitrobenzoic acid with N, N¢-carbonyldiimidazole followed by 2-pyrrolidinone gave 1-(2-nitrobenzoyl)pyrrolidine-2-one (3). Reduction of the latter with 10% Pd-C afforded deoxyvasicinone (4). Reaction of deoxyvasicinone (4) with bromine yielded monobromo-deoxyvasicinone (5). Exchange of bro...

Bromine may act as a catalyst for recombination of ozone and could be more efficient than either nitric oxide or chlorine. The lower atmosphere contains small concentrations of gaseous bromine produced in part by marine activity, in part by volatilization of particulate material released during the combustion of leaded gasoline, with an additional contribution due to the use of methyl bromide a...

the synthesis of 4-(substituted benzylidene)-2-(pyrazin-2-yl) oxazol-5(4h)-one was achieved in two steps, in first step, pyrazine-2-carboxamide  dissolved in etoh, 10% koh solution with clch2cooh produced compound 2-(pyrazine-2-carboxamido) acetic acid (ii) and in second step, compound (ii) in (ch3co)2o with aromatic aldehyde, and catalyst potassium acetate produced title compounds 4-(substitut...

Known polyene amide, clathrynamide A, and three novel related metabolites, debromoclathrynamide A, (4E,6E)-debromoclathrynamide A and (6E)-clathrynamide A, were isolated from an Okinawan marine sponge, Psammoclemma sp. The absolute stereochemistry of clathrynamide A was determined to be 3R,12R by the modified Mosher method. The structures of the three new compounds were elucidated by spectrosco...

A selective and practical bromine-metal exchange on bromoheterocyclics bearing substituents with an acidic proton under non-cryogenic conditions was developed by a simple modification of an existing protocol. Our protocol of using a combination of i-PrMgCl and n-BuLi has not only solved the problem of intermolecular quenching that often occurred when using alkyl lithium alone as the reagent for...

A spectrophotometric method for the determination of chlorine,bromine or iodine ion by using1,5-bis(6-methy1-4-pyrimidyl)carbazone has been established.The ranges of determination were0.355-3.55ppm of Cl-,0.799-7.99ppm of Br and1.27-12.7ppm of F.The proposed method could be applied to the analyses of various halogen-containing organic compounds, including sulfur-containing compounds.Eleven comm...