反应详情

温度

67.5 °C

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 7 at 20 to 25° C. using 5.3 g of HCl solution (32% strength by weight aqueous solution), and the complete solution was heated to 65 to 70° C. and then adjusted to a pH of 1.5 to 3 using 60 g of HCl solution (32% strength by weight aqueous solution). The reaction mixture was cooled to room temperature (25° C.), and the solid was filtered off on a suction filter and washed ten times with 150 ml of water. The yield after drying under reduced pressure at 100° C. was 134.1 g (91.7% of theory). According to HPLC and NMR measurement, the product was free from decanoic acid and from unreacted para-hydroxybenzoic acid. The purity of the product is >99.9% by weight.

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 7 at 20 to 25° C.
5. temperatureThe reaction mixture was cooled to room temperature (25° C.)
6. filtrationthe solid was filtered off on a suction
7. filtrationfilter
8. washwashed ten times with 150 ml of water
9. customThe yield
10. customafter drying under reduced pressure at 100° C.