An acid addition salt of δ-aminolevulinic acid is prepared in such a way that tetrahydrofurfurylamine (VI) is reacted with phthalic anhydride under an anhydrous condition to introduce a phthal group which protects amino group of tetrahydrofurfurylamine to give N-tetrahydrofurfuryl phthalimide (III), carbon atoms of the first- and fourth-positions of thus obtained N-tetrahydrofurfurylphthalimide (III) are oxidized at 80°C using sodium periodate as a oxidizing agent and ruthenium chloride hydrate as a catalyst to yield 5-phthalimidolevulinic acid (II), then the protecting group of 5-phthalimidolevulinic acid (II) is deprotected using an acid to prepare an acid additional salt of δ-aminolevulinic acid. The acid additional salt of δ-aminolevulinic acid is readily converted by neutralization by an alkali to δ-aminolevulinic acid, which is very useful as a precursor of Vitamin B₁₂, heme and chlorophyll.
δ-aminolevulinic acid 的酸加成盐是这样制备的:在无
水条件下,
四氢糠胺 (VI) 与
邻苯二甲酸酐反应,引入保护
四氢糠胺氨基的
邻苯二甲酸基团,得到 N-四氢糠基邻苯二甲
酰亚胺 (III)、以
高碘酸钠为氧化剂,
氯化
钌水合物为催化剂,在 80°C 下氧化由此得到的 N-四氢糠基
酞酰亚胺(III)的第一位和第四位碳原子,得到 5-
酞酰亚
氨基
乙酰丙酸(II),然后用酸脱 5-
酞酰亚
氨基
乙酰丙酸(II)的保护基,制备δ-
氨基
乙酰丙酸的酸性附加盐。δ-
氨基
乙酰丙酸的酸性附加盐经碱中和后很容易转化为δ-
氨基
乙酰丙酸,而δ-
氨基
乙酰丙酸作为
维生素 B₁₂、血红素和叶绿素的前体非常有用。