3-Chloro-5-isoxazoleacetic acid is prepared from 3-chloro-5-isoxazolepropionic acid by conversion of the latter to E-3-chloro-5-isoxazoleacrylic acid. This is first converted to the acid chloride, then to the acid azide, which is subjected to a Curtius degradation and hydrolysed and the hydrolysed product is condensed with hydroxylamine to give the corresponding nitrile, which is hydrolysed to give said 3-chioro-5-isoxazoleacetic acid.
3-Cloro-5-isoxazoleacetic acid 是由 3-Cloro-5-isoxazolepropionic acid 制成的,方法是将后者转化为 E-3-Cloro-5-isoxazoleacrylic acid。首先转化为酰
氯,然后转化为
叠氮酸,
叠氮酸经过 Curtius 降解和
水解,
水解产物与
羟胺缩合得到相应的腈,腈经过
水解得到所述的 3-
氯-5-
异恶唑乙酸。