Catalysis by Acid-Regenerated Cation Exchangers.

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.

CARBONYLS IN OXIDIZING FAT III. THE DISTRIBUTION OF’VOLATILE and NON‐VOLATILE CARBONYLSa

“…The literature indicates that cation exchange resins are frequently powerful catalysts. They are known to catalyze esterification,, interesterification, and saponification (25,34,36) and form acetals (34). Cation ex- change resins also are capable of catalyzing condensation and polymerization of aldehydes (1).…”

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

“…Efforts directed towards addressing these drawbacks currently account for a large proportion of the research being conducted within the flow chemistry community. The continuous processing of slurries, for example, is now routinely performed [44][45][46][47][48], also, the use of scavengers (e.g., solid support reagents) [49][50][51] and devices such as membrane-based continuous separators [52][53][54][55] has come a long way in aiding with in-line purification and work-up issues. Table 4 provides a general summary list of advantages and disadvantages of a flow approach.…”

Low-temperature polycondensation of carboxylic acids and carbinols in heterogeneous media

“…17 Resins such as Amberpany, was donated by the Dow Corning Corporation. Amberlyst-15 was donated by the Rohm lyst-15 have long been known to catalyze esterification, 18,19 but reported uses in polymerization and Haas Company. have been rare, and in every instance water was rigorously removed by azeotropic distillation at Polycondensation of Azelaic Acid and temperatures high enough to induce resin decom-1,10-Decanediol, Method A: position in addition to other side reactions.…”