| 摘要 |
The title salts are prepared in high purity by contacting in an aqueous reaction medium (a) 2-isopropenyl-2-oxazoline present in its free form in low concentration and (b) an acid selected from the group consisting of hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, nitric acid, organic carboxylic acids, alkyl or aryl sulfonic acids and mixtures thereof. The low concentration of 2-isopropenyl-2-oxazoline (IPO) in its free form can be achieved by adding the IPO slowly to the reaction mixture so that it does not accumulate or by maintaining a pH of less than about 2.5 in the reaction mixture so that nearly all of the IPO will be protonated.
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