| 摘要 |
<p>Polyesters (I) based on hydroxycarboxylic produced by converting H-(OCHR-(CR'R'')x-CO)n-OH(II) to H-(OCHR-(CR'R'')x-CO)m-OH (I). In the formulae, R, R', R'' = alkyl and/or H; m, n = whole nos, with m greater than n; and x = 0 or a whole no. The novelty is that the reaction is carried out in the presence of a condensation catalyst (III). Specifically (III) is a cpd of formula R1-N=C=N-R2 (with R1, R2 = opt substd alkyl, cycloalkyl or aryl), R3-C0-R4 (with R3, R4 = opt Hal-substd alkoxy, a 5-, 6- or 7-membered ring (opt with 1 or more C atoms replaced by hetero atom(s) and opt unsatd and/or substd), or Hal (pref C1), R5-S02-X (with 5 = opt substd alkyl or aryl; X = Hal, pref Cl), R6-0-C0-0-R7 (with R6, R7 = opt substd heteroaryl or aryl, or C6H2Y1Y2Y3-Hal (with Y1, Y2, Y3 = H or nitro); pref (III) is phosgene, diphosgene or triphosgene, carbonyldi-imidazole (CDI) or dicyclohexylcarbodi-imide (DCC); reaction is carried out in the presence of an acylation catalyst, pref a 4-dialkylaminopyridine, esp pref 4-dimethylamino-, 4-piperidino- or 4-pyrrolidino-pyridine; (II) are alpha- and/or beta-hydroxycarboxylic acids or oligomers thereof, esp glycols acid, D- and/or L-lactic acid and/or oligomers thereof, or a mixt of these acids and oligomers.</p> |
