HCID 178524392, compound → Picolinic acid

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Reaction Steps

For isolation, the cell-free picolinic acid solution was precipitated with CaCl2 /H2SO4. For this purpose, the cell-free picolinic acid solution from Example 2 was diluted 3-fold and, while stirring, 0.5 equivalent of CaCl2 per equivalent of picolinic acid was added after the cell-free fermentation solution had been heated to 90° C. The resulting calcium/picolinic acid complex precipitated immediately. The resulting complex was cooled to 4° C. with stirring, filtered off on a glass flit (porosity 3) and washed with demineralized water. The filter cake was suspended in demineralized water and acidified to a pH of 2.5 with concentrated sulfuric acid. During this operation, the picolinic acid was dissolved out of the complex and, at the same time, insoluble calcium sulfate was formed. Since the free picolinic acid is very soluble in water it was possible to remove calcium sulfate by filtration. The picolinic acid solution was evaporated to dryness and analyzed. The crude yield was about 70 percent with a purity of 86 percent by titration. The water content was 0.7 percent measured by the Karl-Fischer method.

Provenance & Evidence