Quaternary amino groups

Dry strength additives are usually water soluble, hydrophilic natural or synthetic polymers, the commercially most important of which are starch, natural vegetable gums and polyacrylamides. These polymers are often made in cationic form by the introduction of tertiary or quaternary amino groups into the polymer, and are therefore polyelectrolytes. They are thus also able to function to some extent as drainage and retention aids. 

Fluorine containing ammonium salts. As amino compounds often have marked physiological action, it seemed worth while to prepare compounds containing both fluorine and a quaternary amino grouping. 

Nevertheless, in many cases, hydrogcnolysis docs not occur readily however, the ammonium salt of the Mannich base appears more suitable for a successful reaction. Thus, several ortho-phenolic Mannich bases arc hydrogenated as hydrochlorides, in order to avoid the presence of the intramolecular hydrogen bond between OH and N, which is responsible for the weak reactivity of the free Mannich base. ITie ferroccnyl Mannich base 282, containing both tertiary and quaternary amino groups, gives 2-di-methylaminomethyl-l-(2-methylferroccn-l-yl) ferrocene (283) upon reaction of the more reactive quaternary ammonium moiety. ... 

Equally unusual is hydrogenolysis of a bond between an aromatic ring and a quaternary amino group. Phenyltrialkylammonium iodides are reductively cleaved to benzene and trialkylamines by electrolysis (equation 85). ... 

Anion-exchange chromatography on membranes, disks, and rods bearing mainly quaternary amino groups or diethylaminoethyl groups as ligands has been used for the separation of serum proteins, microbial proteins and enzymes, membrane... 

In the synthesis of hydroxamic acid 19a, having a free quaternary amino group (see Scheme 4.4), the intermediate sulfone 21 was synthesized by Pd-catalyzed reaction of phenol with p-bromo derivative 20 [24], Lithiation of 20, followed by nucleophilic addition to the A-Cbz imine of trifluoropyruvate 22 [25] afforded the a-CF3 a-amino acid derivative 23 in fair yields. Basic hydrolysis of the ester function gave the carboxylic acid 24, which was submitted to condensation with ()-15 n-hydroxylamine, affording hydroxamate 25. The subsequent hydrogenolysis of 25 afforded the target molecule 19a. 

Today, silanes are available or can be synthesized for a one-step surface thesis of all the different types of ion-exchangets. However, the preparation of some of the older types is likely to involve multiple surface reactions. The details of the preparation of many commercial products is not public knowledge, so it is difB t to know which products are made by which procedure. When multiple reactions are carried out on the surface, a more heterogeneous product is obtained. For example, if the silica is first derivatized with propylamino silane, and the product is subsequently quatemized with methyl iodide, an appreciable amount of tertiary amino groups will remain on the surface. Such an ion exchanger has properties different from those of an ion exchanger that contains purely quaternary amino groups. 

As bretylium did not prove satisfactory, one alternative was to replace the quaternary amino group in bretylium by the guanidine group of guanethidine. The most effective compound of a series reported by Boura et al. [37] was found to be bethanidine ... 

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