Ion exchange resin Amberlite

Filtered broth was passed at 2.5 ml/min through a resin column (2.5 cm diameter, 28 cm length) packed with 150 ml of ion exchange resin Amberlite IRC-50 sodium type (Rohm and Haas Co., U.S.A.). The column was washed with water, eluted with 0.5 N HCI at a flow rate 1.3 ml/min. The eluates were fractionated each 10 ml and tuberactinomycin-N activity was found at fractions No. 45-63 obsarved by ultraviolet absorption method and bioassay. 

Silica gel supported sodium metaperiodate was used for the selective oxidation of dibenzyl sulphide80. Metaperiodate anion soaked on strongly basic-ion-exchange resins Amberlite IRA-904 or Amberlyst A-26 was found to be able to oxidize sulphides into the corresponding sulphoxides in 82-99% yield81. 

Heyd has studied the stability of neomycin in aqueous gels and formulated a satisfactory product by adsorbing the antibiotic on an ion exchange resin, Amberlite IRP-69M, prior to incorporation in the gel. 

Iodometric titration, 50, 17 Ion-exchange resin, Amberlite IR-120, cyclization with,... 

Alternatively, l-oxo-l,2,3,4-tetrahydroquinolizinium ion (111 Scheme 73) and its congeners may be converted to derivatives of 1-hydroxyquinolizinium ion (63JCS2203). The bicyclic ketone (111) can be brominated to yield the 2-bromo (112) or the 2,2-dibromo derivative (113). Action of boiling acetic anhydride converts the monobromo ketone (112) to 2-bromoquinolizinium bromide (Table 2). If the same bromo ketone (112) is heated with ion-exchange resin (Amberlite IRA-400) loaded with hydroxyl ions or, alternatively, heated with silver acetate in water, the 1,2-dihydroxyquinolizinium ion is formed and may be recovered as the picrate (Scheme 74). 

Mixed-bed ion-exchange resin amberlite MB3 (100 g Merck) is pretreated with 500 ml 10% acetic acid for 4 h, washed with distilled water and dried over 3 days. 

Ion-exchange resins Amberlite ion-exchange resin, 240 Amberlyst ion-exchange resin, 152, 287... 

Weakly nucleophilic heterocyclic amines have efficiently been acylated utilizing solid-supported reagent 7 [13]. Here, the electron-deficient phenol group allows for intermediate anchoring of an acyl chloride onto the resin which then is released upon treatment with various 2-aminopyridines and 2-aminothiazoles. Traces of unreacted starting material were then conveniently removed by addition of the acidic ion exchange resin Amberlite IRA-120. 

A convenient resolution method was recently developed (123) which uses the specific affinity of the ion exchange resin Amberlite IRA 400 for tartrate ions. A column of the resin in the (+) tartrate form may be used to resolve many racemic compounds, including [Co(en)3]3+, [Co(pn)3]3+, [Cr(en)3]3+, [Rh(en)3]3+, cis-[Co(en)2Cl2]+, [(en)2Co(OH)2]3-Co + etc. It might be expected that the more readily eluted enantiomers in a series of analogous complexes should have related configurations, provided that adsorption occurs at the same sites on the column and indeed, (—)[Co(en)3]3+, (—)[Co(pn)3]3+, (—)[Cr(en)s]3+, and (+)[Rh (en)3]3+ were all eluted first from their racemic mixtures. 

Compound (2.20 g, 3.7 mmol) (19) is dissolved in 50 mL methanol. Sodium methoxide solution (50 mL, 0.2 M) is added and the solution stirred at room temperature for 2 h. The mixture is neutralized with ion-exchange resin (Amberlite lR-120 [H ]), filtered, and then the solvent removed in vacuo. The product is lyophilized from acetonitrile/water (1 1) to yield the title compound (1.49 g,... 

Raney nickel catalysts (1, 723). The usual preparation of Raney nickel catalysts W-2 and W-h requires a tedious washing process with distilled water to remove the last traces of salt. Wynberg ct a P report that demineralization can be accomplished readily with an ion-exchange resin (Amberlite IR 121), hydrogen form). The resulting catalysts are somewhat more active than those prepared by the Organic Syntheses procedures. 

Fig. 6.22 Measured and calculated isotherms for pure components and mixtures of glucose and fructose (adsorbent ion exchange resin Amberlite CR 1320 Ca, dp = 325 im, eluent water for additional data see Appendix B.3).

Dimensionless degrees of freedom do not always transfer to other column designs as perfectly as shown in Fig. 7.1. In many cases some deviations in the concentration profiles have to be taken into account. These cases will now be demonstrated using a second exemplary separation problem the chromatographic separation of 1 1 mixture of glucose and fructose on ion-exchange resin Amberlite CR 1320 Ca from Rohm Haas (325 pm particle diameter) (Tab. 7.2). 

Adsorbent and catalyst ion-exchange resin Amberlite 15 (Rohm u. Haas)... 

Catalysis of Lobry de Bruyn-Alberda van Ekenstein reactions by a strongly basic, ion-exchange resin [Amberlite IRA-400(OH)] has now been demonstrated. Duff has reported that alkaline impurities present in paper brought about such transformations of several sugars when paper chromatograms thereof were dried at 110°. 

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