Process for the preparation of aromatic dicarboxylic acid dichlorides
AssigneeBayer Aktiengesellschaft
InventorsDieter Freitag, Manfred Schmidt, Ludwig Bottenbruch
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Abstract
A one-step process for the preparation of pure aromatic dicarboxylic acid dichlorides by reacting an aromatic dicarboxylic acid or an aromatic dicarboxylic acid mixture with phosgene in the presence of a catalyst and, optionally, in a solvent or diluent, by using tertiary phosphines as catalysts, and the use of the dicarboxylic acid dichlorides obtained for the production of polycondensates.
Claims4
A process for preparing aromatic dicarboxylic acid dichloride which comprises reacting an aromatic dicarboxylic acid selected from the group consisting of ##STR4## and mixtures thereof wherein R is H, C.sub.1 -C.sub.4 -alkyl or halogen and
- X is a single bond, --O--, --S--, --CH.sub.2 --, ##STR5## or C.sub.5 -C.sub.7 cycloalkylene with phosgene in the presence of a catalytic amount of a tertiary phosphine of the formula ##STR6## wherein R.sub.1, R.sub.2 and R.sub.3 are each selected from the group consisting of C.sub.1 -C.sub.8 alkyl, C.sub.6 -C.sub.10 aryl, C.sub.7 -C.sub.20 aralkyl and C.sub.7 -C.sub.20 aralkyl.
Dependencies are inferred from the claim text.