Vol. 58and concentrated. There resulted a viscous yellow oil boiling at 280-285°( 2 mm.). The yield was 4.4 g. or 84.1%. Anal. Caled, for CuHieOaBr: C, .5; , 4.1; -OCHs, 9.8. Found; C, 60.8; , 4.0; -OCHs, 10.0.o-Bromophenylglyoxylic Acid.-This acid was purified by several crystallizations from methyl alcohol and water. The thin colorless needles melted over a range with decomposition as reported by Russanow. For a concentra-tion of 0.03449, molecular conductivity 266.21, and conductivity at infinite dilution 348, the ionization constant at 25°was calculated to be 8.6 X 1Q-Z.

No abstract

Little has appeared in the literature on anion exchange reactions for metal recovery, although organic cation exchangers are being used for this purpose. The present investigation was undertaken to study anion exchange for recovery of metals which form complex anions. Satisfactory adsorption and recovery have been demonstrated with chromium, gold, iron, molybdenum, palladium, platinum,and vanadium, using differently pes of complex anions. A more extensive study was made of chromium recovery. The anion exchange mechanism of the adsorption was demonstrated. Adsorption on different anion exchanger salts and from several influents warcarried out. Best results were obtained with adsorption from a neutral chromate sokition on the anion exchanger chloride. Recovery experiments were run with several salts, bases, mixtures of the two, and with an acid. Alkaline regenerants were found best. Acid regenerants caused oxidation of the anion exchange resin and reduction of the chromate. Precious metals ere recoverable by ashing the resin. Metal concentrations of more than twenty-five times the Influent concentration were obtainable without recycling ... A typical automatic ion exchange unit Is reproduced at the right; this equipment may be used for processes ranging from the softening of water to the recovery of metal.

No abstract

Acid-regenerated cation exchangers, long used for «ater treatment and related ion exchange processes, are applied as catalysts for esterification, acetal synthesis, ester alcoholysis, acetal alcoholysis, alcohol dehydration, ester hydrolysis, and sucrose inversion.Several types of organic cation exchangers were used, and their continued re-use was demonstrated.These catalysts permit simplified procedures for reactions involving high boiling and viscous compounds, because the catalysts can be separated from the reaction products by simple filtration.Compounds which polymerize in the presence of acids have been esterified directly by the use of these cation exchangers.EARLY in 1941 all investigation of the use of acid-regenerated cation exchangers as catalysts for organic reactions was undertaken in this laboratory. The preliminary results were promising and, during the intervening years, the method has been used for an esterification process in this country. However, the pressure of war research forced postponement of further work on this problem. We have been led to publish our incomplete preliminary results at this time by the recent publication of a German technical report on the use of Wofatit, a cation exchange resin, as a catalyst for certain esterification, ester interchange, and hydrolysis reactions (£).The literature disclosed two references which, at first glance, appear to report the use of ion exchangers as catalysts. Cheetham (f) catalyzed the condensation of certain resins by adding to the reaction mixture an acid-regenerated cation exchange resin and a salt. In this case it is quite probable that the cation exchange resin reacted with the salt, producing an equivalent amount of mineral acid which, in turn, was the actual catalyst. Likewise, Spurlin (6) employed a methylated anion exchange resin, together with sodium chloride, as a substitute for calcium oxide in the synthesis of pentaerythritol. Here also it is probable that the anion exchanger reacted with the salt to yield sodium hydroxide, which was the actual condensation catalyst.