The preparation 6-epi-ampicillin by hydrolysis of 6-epihetacillin is described. During this conversion, the formation of a diketopiperazine was also observed. The best yield was obtained at pH 7.0 and room temperature for 3-7 hours. The lowest yield of 6-epi-ampicillin and the highest formation of the diketopiperazine occurred in pyridine-acetic acid-water. Treatment of ampicillin (with D-aminophenylacetyl side chain) with nitrous acid gave α-hydroxybenzylpenicillin with about 66% of L- and 34% mandelyl side chain. Reaction 6-epi-ampicillin gave 6-epi- α-hydroxybenzylpenicillin with practically the same ratio of L- and D-isomers.
通过6-epihetacillin的
水解制备6-epi-
氨苄西林的过程被描述。在此转化过程中,还观察到了二酮
哌嗪的形成。在pH 7.0和室温下进行3-7小时,获得了最佳产率。在
吡啶-
乙酸-
水体系中,6-epi-
氨苄西林的产率最低,而二酮
哌嗪的形成量最高。用
亚硝酸处理具有D-
氨基苯乙酰侧链的
氨苄西林,得到了含有约66% L型和34%
扁桃酸侧链的α-羟基苄
青霉素。反应6-epi-
氨苄西林得到了实际上L型和D型比例相同的6-epi-α-羟基苄
青霉素。