Strong-base ion exchange

Solid phase-transfer reactions.2 A strong base ion-exchange resin (Duolile A-109, Diamond Shamrock) can serve as a solid phase-transfer catalyst for synthesis of /1-lactams (3) from oc-methyl-a./l-dibromopropionyl chloride (I) and an amino acid (2) U / 9, 360). 

Strong-base ion-exchange resins Korngold, Belayev and Aronov (2001)... 

In the tosylation of LXI, only the equatorial hydroxyl group reacts readily introduction of a second tosyl group (onto the axial oxygen atom) is very difficult. Detosylation is carried out with a strong-base ion-exchange resin to minimize epoxide migration (see p. 182) if alkali is used, rac-inositol is the main product. 

Step 3. Read about the radiochemistry of iodine to improve your understanding of the radioanalytical chemistry of iodine. An old but helpful monograph is Radio chemistry of Iodine, NAS-NS-3062, by Milton Kahn and Jacob Kleinberg, Office of Scientific and Technical Information, US DOE, 103 pp (1977). A copy may be obtained from the instructor, the library, or internet search. Also read about ion-exchange theory and practice, and in particular, the relative affinity of anions for strong-base ion-exchange material. 

High-Purity Water Obtain High-Purity Water from a mixed-bed strong-acid, strong-base ion exchange apparatus capable of producing water of more than 15-megohm resistivity. 

The use of spectroscopic methods to facilitate the most informative analysis of the factors involved in such selective complexation of metal ion by strong add and strong base ion exchangers has provided an important direction of research for the author and his colleagues. 

Strong-base ion-exchange fibrous materials (SBF) were tested as sorbents for purification of air from acid impurities exemplified by S02- The SBF exchangers were prepared by amination with the trimethylamine of chloromethylated polystyrene grafted on polypropylene fibres. 

Fig. 2. Technological scheme of preparation of strong-base ion-exchange fibres 1 - reactor for...

Figure 8,4 Strong-base ion-exchange monomer (quaternary ammonium struc-...

Strong-base ion exchangers have been obained by treatment of chloromethylated resins with both aliphatic and aromatic tertiary amines. Similar weak-base ion-ex-change resins have been synthesized using ammonia as well as primary and secondary amines instead of tertiary amines. 

The yields (Table I) of resins varied with the method and temperature of preparation. The exchange capacities were found to be below the theoretical values. However, in most cases the exchange capacities were comparable to those of commercial strong base ion exchange resins determined by the already outlined procedure. 

Monomer can be removed from solution by strong-base ion-exchange resin, presumably because it is ionized to HSiOj" by the OH" ions at the resin surface, and is then adsorbed. 

Pyridinium betaines can be prepared conveniently from the esters with Dowex 1, a strong base ion exchanger... 

An aq. soln. of l-methyl-3-carbomethoxypyridinium iodide passed through a column of Dowex-1 (OH form), a strong base ion exchange resin, and eluted with water trigonelline. Y 87.4%. F. e. s. E. M. Kosower and J. W. Patton, J. Org. Ghem. 26, 1318 (1961). 

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