Concurrent Treatment Involving Carboxylic Groups

As already mentioned, the perfiuorinated anhydrides TFAA, HFBA and less often the more expensive PFPA, can promote esterification of carboxylic groups provided that they are in a molar excess over the haloalcohol present. It is logical to suppose that even polyfunctional acids might be effectively treated, since side chain groups are acylated smoothly. This has been confirmed experimentally by treating hy-droxyphenolic acids, bile acids and even amino acids, the carboxylic and side chain groups of which are esterified and acylated simultaneously. It is assumed that the reaction proceeds in two steps, i.e. by the formation of mixed anhydride intermediate that is subsequently alcoholysed to the ester, as shown by p-hydroxyphenylacetic acid treated with PFPA/HFIP (reaction [I]). Derivatization of a number of car-boxylic acids has been achieved by treatment with TFAA and HFB or TFE in the presence of an organic base with heating to 60°C for 30-40 min.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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