Dibenzofuran-2-sulfonic Acid. I. The Free Acid and its Alkali Salts

Abstract

Dibbnzofuran-2-sulfonic Acid and its Alkali Salts 1593 VIII (0.2 g.) was dissolved in 8 ml. of ethanol and converted to the 2,4-dinitrophenylhydrazone by treatment with a solution of 0.16 g. of 2,4-dinitrophenylhydrazine in 0.8 ml. of sulfuric acid and 1.2 ml. of water, diluted with 4 ml. of ethanol. The mixture was heated at the reflux temperature for two hours after the appearance of a precipitate. On cooling, filtering and washing with cold alcohol a yield of 0.25 g. (88%) of the dinitrophenylhydrazone was obtained, m. p. 169-170°. After recrystallization from ethanol-ethyl acetate, acetonitrile and chloroform-carbon tetrachloride, the derivative was a crystalline crimson powder with a constant m. p. of 177-178°.

Electrochemistry of anilines. 6. Reactions of electrogenerated biphenylylnitrenium ions

“…Genies and Lapkowski have found spectroelectrochemical evidence for the involvement of a nitrenium ion in the electropolymerization of unsubstituted aniline.3 A persistent ion 4c has been characterized by spectroscopic and electrochemical methods. 4 The hypothesis has been formulated that the ions5 are formed by an overall two-electron transfer via radical cations 26 and most likely the nitryl radicals 3 (Scheme I).…”

“…(5) The positive charge is distributed over the entire aromatic system in these cations. 4 From the possible mesomeric structures only that having the charge at the NH group is shown here.…”

Inorganic Gravimetric Analysis

“…The optimum pH values for the precipitation of copper, iron, and aluminum were, respectively, 3.6 to 6.0, 3 to 5.5, and 3.6 to 6.4. Wendland, Smith, and Muraca (160) reported that 2-dibenzofuransulfonic acid appeared to be a general metalion precipitant even for the alkali metal ions. Hovorka and Holzbecher (78) examined the reactions of cations with the /3-semicarbazone of isatin and its derivatives.…”