I am performing solution polymerization of diols (PLLA diols have a secondary alcohols, and can also have trace carboxylic acid endgroups) using triphosgene. I am continuing to have problems with solubility and low Mn. I know that if triphosgene reacts with a carboxylic acid you'll get an acid chloride and if triphosgene reacts with a diol you'll get a chloroformate. But once you have the acid chlorde and the chloroformate, will they react? And if so is the reactivity the same? Theres alot of strange things happening in these reactions. Hoping someone can help clear it up. thankx!
Dear Alex
I guess you are planning to produce carbonate polymers, in fact triphosgene is a weighable form of phosgene (very toxic gas) and inserts carbonyl groups into diols and hydroxy acids. In the absence of base, HCl is generated. In the reaction with carboxylic acids, carbon dioxide is released as well. If you wanted to avoid the generation of a strong acid like HCl in the process, you can employ carbonyl-diimidazole in DMF with heating to at least 50°C.
Best regards, Raffaello
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