Sulfone resin

Dihydroxybenzophenones are used for the syntheses of dyes, polymers, and medicines. They are prepared by the condensation of resorcinol with benzoic acids. Catalysts used for this transformation are sulfonic resins (99), boron trifluoride (100), or zinc chloride in the presence of POCl (101). 

The sulfonated resin is a close analogue of -toluenesulfonic acid in terms of stmcture and catalyst performance. In the presence of excess water, the SO H groups are dissociated, and specific acid catalysis takes place in the swelled resin just as it takes place in an aqueous solution. When the catalyst is used with weakly polar reactants or with concentrations of polar reactants that are too low to cause dissociation of the acid groups, general acid catalysis prevails and water is a strong reaction inhibitor (63). 

Recovery of dilute acetic acid is achieved by esterification with methanol using a sulfonated resin (Dowex 50w) in a packed distillation column (54). Pure methyl acetate is obtained. This reaction is second order in acetic acid, 2ero order in methanol, and partially diffusion controlled. 

The polyamines putrescine, cadaverine, spermidine, and spermine, which are seen at elevated levels in some victims of cancer, were separated on a Technicon (The Technicon Company Chauncey, NY) TSM Amino Acid Analyzer packed with an 8% divinylbenzene-co-polystyrene sulfonated resin with post-column ninhydrin detection.111 Amines such as ethanolamine, noradrenaline, hexamethylene diamine, methoxytryptamine, spermine, and spermidine were separated from amino acids on a DC-4A cation exchange resin.112 A similar approach, using a Beckman Model 121M amino acid analyzer equipped with an AA-20 column, was also successful.113 A Polyamin-pak strong cation exchange column (JASCO) was eluted with a citrate buffer for the detection of putrescene, spermine, cadaverine, and 1,5-diaminohex-ane from rat thymus.114 A post-column o-phthaldehyde detection system was used. 

This paper describes our efforts to synthesize a series of thermally stable sulfonated resins and to evaluate their activity in a model reaction of 1-butene hydration to sec-butanol. 

Appropriately functionalized resins can sequester excess nucleophiles from solution-phase reactions. Thus the calcium sulfonate resin 4 captures tetra-n-butylammonium fluoride (TBAF) from a variety of desilylation reactions.22,24 Polymer-bound tetra-n-butylammonium sulfonate and insoluble calcium fluoride are formed. The applicability of this strategy was illustrated for deprotection of (3-trimethylsilylethyl esters as well as silyl ethers. 

TBAF-quenching calcium sulfonate resin 4 and acidic-quench resin 51 in step 4 and... 

The sulfinated PCTFE derivative was converted to the sulfonated derivative by stirring the sulfinate in 30 wt % hydrogen peroxide/tetrahydrofuran for 2 days. The infrared spectrum (Figure 3) for the product polymer indicates formation of the sulfonated resin. 

Since the mid-fifties sulfonated resins based on styrene/divinylbenzene copolymers, initially developed as ion exchangers mainly for water treatment, nave also been used as strongly acidic solid catalysts. Witn few exceptions, industrial application in continuous processes is limited to the manufacture of bulk chemicals, sucn as Disphenol A, (meth)acrylates, metnyl ethers of branched olefins (MTBE, TAME) and secondary alcohols (IPA, SBA). 

For instance, methyl tert-butyl ether (MTBE) used worldwide as an octane improver in gasoline is produced at a still growing global capacity of approx. 8 million mt/yr using sulfonated resins as catalysts (ref. 1). 

In a one-step process a Pd-doped sulfonated resin (e.g. a standard macro-porous type with U.l-5 % Pd) catalyzes both the condensation of 4 yielding 6 and the hydrogenation of b to ] in a single reactor. RWE-DEA has been producing ] for many years by this process developed in their labs and pilot plants. 

The cheapest catalyst for the first reactor is a gel-type sulfonated resin (ft... 

However, when utilized on a conmercial scale, primarily the reaction rates, referring to catalyst quantity or bulk volume, are important because they determine reactor size and amount of catalyst required. Referring the reaction rate in table 1 to one gram of resin, the surface-sulfonated ion exchange resin F 027 is the least efficient because the gel areas do not contain any sulfonic acid groups. The other four resins, however, are quite similar they are homogeneous and almost completely sulfonated. Macroporous and surface-sulfonated resins are higher priced, but not more efficient in conmercial application. 

The hydration reaction of alkynes leading to carbonyl compounds is generally carried out in dilute acidic conditions with mercuric 1on salts (often the sulfate) as catalysts (ref. 5). Only very reactive alkynes (phenylacety-lene and derivatives) can be hydrated in strong acidic conditions (HgSO ) without mercury salts (ref. 6). Mercury exchanged or impregnated sulfonic resins have also been used in such reactions (ref. 7). Nevertheless, the loss of the catalyst during the reaction and environmental problems due to the use of mercury make this reaction method not as convenient as it should be for the preparation of carbonyl compounds. 

Cr(III) compounds, like Cr(III) hydroxide deposited on montmoril-lonite,408 Cr(III) stearate,409 Cr(acac)3,409b Cr(III) on a perfluori-nated sulfonic resin (NAFK),410 chloro(tetraphenylporphyrinate) chromium(III) [(TPP)CrCl] (6)411 and (salen)oxochromium(III) complex (7),412,413... 

Both the quality of TFP resin and the resulting polymeric-activated resins may be quantitatively determined by 19F NMR spectroscopy.1 This nondestructive technique takes advantage of the high sensitivity, natural abundance (the 1/2 spin nucleus 19F is 100% abundant), and large chemical shift dispersion ( 200 ppm) of the 19F nucleus. The 19F NMR spectrum of TFP resin shows two resonances at 148 and 165 ppm (Fig. 3), each corresponding to 2 equiv. fluorine nuclei. The 19F NMR spectrum of TFP-activated carboxylate and sulfonate resins shows two resonances at ca. 

Alkylglucosides have already been directly synthesized using heterogeneous catalysts as, for example, macroporous sulfonated resins but with a relatively important amount of oligosaccharides.[38,39] However, it was recently shown that acid zeolites were capable of performing the direct Fischer synthesis by avoiding the formation of oligomer species.[18,40,41]... 

The sulfonated polystyrene beads can be used as a cation exchange resin. For example, if the sulfonated resin is treated with sodium hydroxide, the sodium salt of each of the sulfonic acid groups is formed. This resin can then be employed to exchange sodium cations for other cations in an aqueous solution. 

The structure chosen from this system for further development was the 20% sulfonate resin. It seemed to us to be a good compromise, possessing the best balance of physical properties for a general purpose material and having a good degree of hydrolytic stability. 

A great advantage of such systems as that based on calcium sulfonate resins is that it is a purely physical phenomenon, in the sense that no permanent change occurs in the resin from cycle to cycle. In principle, the resins do not require regeneration, and should be usable for many cycles of operation. 

Other fractionation systems that employ resins have been advocated. In one, the hydrazine salt of sulfonate resins functions by virtue of its relatively greater retardation of D-glucose as compared to D-fruc-tose.54 In this process, D-fructose appears in the eluate first, followed by the D-glucose fraction. 

Other systems for fractionating D-fructose-D-glucose mixtures are based on cationic resins in the hydrogensulfite-sulfite form,55 strontium sulfonate resin,58 silver sulfonate resins,57 and polymeric aryl-boronic resins.58 The arylboronic systems have been used to effect isomerizations to relatively high D-fructose D-glucose ratios, as well as to cause fractionation. 

A polyimide sulfone resin has been prepared having a Tg of roughly 250°C and a M of roughly 35,000 daltons while still remaining melt processable. When extruded and converted into molded articles at 370°C to 390°C, the molecular weight of the polyimide was diminished by less than 30%. 

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