反应详情

For example, Japanese Unexamined Patent Application Publication No. 54-163516 discloses a process for preparing a crystalline sorbic acid. This process includes the steps of preparing a polyester from ketene and crotonaldehyde, decomposing the polyester with hydrochloric acid in the presence of, for example, a urea compound to yield a decomposition reaction mixture, separating the decomposition reaction mixture by filtration, and washing the residue to yield a crude sorbic acid, adding a sodium hydroxide aqueous solution to the crude sorbic acid to yield a sodium sorbate aqueous solution, treating the aqueous solution with activated carbon, neutralizing and cooling the treated solution to crystallize sorbic acid. Japanese Examined Patent Application Publication No. 44-26646 discloses a process for producing a crystalline sorbic acid. The process includes the steps of preparing a polyester from ketene and crotonaldehyde, decomposing the polyester with hydrochloric acid having a concentration of 35% by weight or more at temperatures ranging from room temperature to around the boiling point of the hydrochloric acid used, cooling the reaction mixture, separating a crude sorbic acid by filtration, washing the crude sorbic acid with water, putting the washed crude sorbic acid into water, heating and dissolving the sorbic acid to yield a solution, adding activated carbon to the solution, boiling the mixture, and filtering the mixture while heating, and gradually cooling the resulting filtrate to yield a crystalline sorbic acid.