| 摘要 |
<p>Liq. phase prepn. of C-alkyl-triethylenediamines (I) is described. A piperazine feedstock (II) is heated to 220-300 degrees in the presence of a pentavalent acidic P cpd. (III) contg. is not 1 R-O-P grp. (R is H or monovalent organic radical). (where each R is H, 1-6C hydrocarbon alkyl; each R' is H, 1-4C alkyl; providing not all RR' = H). Use of the catalyst (III) affords (I) in good yield with high selectivity. In addn., the liq. phase reaction avoids the formation of polymeric residues and allows ready sepn. of (I) (useful as urethane catalyst). In an example, methyl triethylenediamine was prepd. as an overhead product in 77 mol.% yield by heating a mixt. of N-(2-hydroxyethyl)methylpiperazines PhP(O)(OH)2, and 'Dowthermal A' (RTM) for 20 hr. at 245-257 degrees.</p> |
