Method for producing aminobenzoic acid or an aminobenzoic acid derivative product

A process for preparing aminobenzoic acid or an aminobenzoic acid conversion product, comprising:

• (I) fermenting a raw material comprising:
• a fermentable carbon-containing compound, and
• a nitrogen-containing compound,
• in a fermentation reactor using a microorganism and a calcium salt, wherein the microorganism contains a genetic modification to accumulate aminobenzoic acid in the fermentation reactor,
• so as to obtain a mixture suspended in an aqueous fermentation solution, the mixture comprising undissolved microorganisms and precipitated calcium aminobenzoate;
• (II) (1) isolating the
• (1)(i) precipitated calcium aminobenzoate or
• (1)(ii) mixture comprising undissolved microorganisms and precipitated calcium aminobenzoate
• obtained in step (I) from the aqueous fermentation solution,
• (2) converting the aminobenzoate bound in the calcium aminobenzoate to a water-soluble form to form a water-insoluble calcium salt other than calcium aminobenzoate by adding an aqueous phase containing cations that form water-soluble aminobenzoate salts and anions that form water-insoluble calcium salts to the isolated calcium aminobenzoate from (1)(i) or to the mixture comprising undissolved microorganisms and precipitated calcium aminobenzoate from (1)(ii),
• so as to obtain a suspension comprising
• (2)(i) the precipitated water-insoluble calcium salt or
• (2)(ii) a mixture comprising undissolved microorganisms and the water-insoluble calcium salt
• in an aqueous solution of aminobenzoate, and
• (3) separating the aqueous solution of aminobenzoate obtained in step (2) from the precipitated water-insoluble calcium salt from (2)(i) or from the mixture comprising undissolved microorganisms and the water-insoluble calcium salt from (2)(ii);
• (III) introducing carbon dioxide at a pressure of greater than or equal to 1.50 bar(abs.) into the aqueous solution of aminobenzoate separated off in step (II)(3) to separate aminobenzoic acid out, so as to form a suspension containing aminobenzoic acid in an aqueous solution;
• (IV) isolating the aminobenzoic acid separated out in step (III) by lowering the pressure with release of carbon dioxide to give a carbon dioxide-depleted aqueous solution that has been freed of aminobenzoic acid separated out;
• (V) using the aqueous solution obtained in step (IV) that has been depleted of carbon dioxide and freed of aminobenzoic acid separated out as a constituent of the aqueous phase added in step (II)(2);
• and
• (VI) optionally further converting the aminobenzoic acid separated off in step (IV) to an aminobenzoic acid conversion product, wherein step (VI) comprises:
• (1) decarboxylating the aminobenzoic acid to give aniline;
• (2) decarboxylating the aminobenzoic acid to give aniline, followed by acid-catalyzed reaction of the aniline with formaldehyde to form di- and polyamines of the diphenylmethane series;
• (3) decarboxylating the aminobenzoic acid to give aniline, followed by acid-catalyzed reaction of the aniline with formaldehyde to form di- and polyamines of the diphenylmethane series, followed by reaction with phosgene to form di- and polyisocyanates of the diphenylmethane series;
• (4) decarboxylating the aminobenzoic acid to give aniline, followed by conversion of the aniline to an azo compound;
• (5) converting the aminobenzoic acid to an amide;
• or
• (6) converting the aminobenzoic acid to a conductive polymer, the conductive polymer optionally comprising polyanthranilic acid.