Amberlite IR 4B resin

Aluminum chloride-phosphorus oxychloride complex, 31, 88 Amberlite IR-4B resin, 32, 13 Amidation, of isocyanic acid with bromo-aniline and other aromatic amines, 31,8... 

The resulting e-aminocaproic acid hydrochloride is converted into the amino acid by means of a column containing Amberlite IR-4B resin (Note 2) ... 

Methionine (7 .S-2-amino-4-methylthiobutyric acid) ]59-51-8] M 149.2, m 281"(dec), pKJ 2.28, pK 9.21. Crystallise it from hot water or EtOH. Also purify it by dissolving it in H2O and passing through an Amberlite IR-120 resin (NH4 form). The eluate is concentrated and then passed through Amberlite IR-4B resin, and this eluate is evaporated to dryness. The residue is washed with EtOH, then Me2CO, dried and recrystallised from aqueous EtOH (colourless plates) [Baddiley Jamieson J Chem Soc 4283 7954]. [Greenstein Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 p 2125 1961, Beilstein 4 IV 3190]... 

Raney Ni has also been used for removal of a secondary bromine, and has been applied for the synthesis of deoxy cyclitols with addition of Amberlite IR-4B anion-exchange resin to bind the liberated acid202 205 (eq. 13.110204). 

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