反应详情

69.1 g (0.5 mol) of para-hydroxybenzoic acid were first dissolved in 200 ml of water and 300 ml of isopropanol and this solution was adjusted to a pH of 10.5 at 20 to 25° C. using 87.4 g of NaOH solution (32% strength by weight aqueous solution, 0.7 mol). Metered in to this solution at a pH of 10.5 subsequently, over the course of three hours, were 95.4 g (0.5 mol) of decanoyl chloride. The pH was held at 10.5 using 40.5 g of NaOH solution (32% strength by weight aqueous solution, 0.324 mol) and the temperature was held at 20 to 25° C. The batch was stirred for one hour thereafter. Subsequently the reaction mixture was adjusted to a pH of 1.5 to 3 at 20 to 25° C. using 65.3 g of HCl solution (32% strength by weight aqueous solution). The reaction mixture was filtered on a suction filter. Here there were considerable problems, since the suction filter/filtration unit clogged up, owing to the size of the product crystals. The experiment had to be terminated at this point. The same occurs if the product is precipitated at 65° C. and the reaction mixture is filtered at 35 to 65° C.

1. customwas adjusted to a pH of 10.5 at 20 to 25° C.
2. customover the course of three hours
3. customwas held at 20 to 25° C
4. customwas adjusted to a pH of 1.5 to 3 at 20 to 25° C.
5. filtrationThe reaction mixture was filtered on a suction
6. filtrationfilter
7. filtrationsince the suction filter/filtration unit
8. customto be terminated at this point
9. customis precipitated at 65° C.
10. filtrationthe reaction mixture is filtered at 35 to 65° C.