Cation-exchange chromatography and selective complexation in the isolation of branched acyclic polyamines : Syntheses of Ethylidynetris(methanamine) [tame], 2,2-Bis(aminomethyl)propan-1-ol [hmmp], 4,4',4''-Ethylidynetris(3-azabutan-1-amine) [sen] and 5,5',5'-Ethylidynetris(4-azapentan-1-amine) [stn]

Abstract

Large-scale syntheses of ethylidynetris(methanamine)* (tame), 2,2-bis(aminomethyl)propan-1-ol* (hmmp), 4,4',4?-ethylidynetris(3-azabutan-1-amine)* (sen) and 5,5',5''-ethylidynetris(4-azapentan-1-amine)* (stn) are described. The pure hydrochloride salts of tame, hmmp, sen and stn are isolated directly from the crude amine mixtures by acidification and cation-exchange chromatography. Alternatively, selective complexation as [Co(hexamine)] Cl₃ followed by Zn/HCl reduction and cation-exchange chromatography is used to isolate the hexamines sen and stn as their hexahydrochloride salts. These isolation procedures are exceptionally efficient compared with the conventional solvent extraction and (often pyrolytic) high-vacuum distillation methods.