作者:Yasuhiro Chigira、Mitsuo Masaki、Masaki Ohta
DOI:10.1246/bcsj.42.224
日期:1969.1
α-Ethoxy- and α-acetoxycinnamoyl chlorides were synthesized by treatments of α-ethoxy-and α-acetoxycinnamic acid with thionyl chloride and oxalyl chloride, respectively, and reactions of ammo acid esters with the cinnamoyl chlorides were investigated in order to seek for a synthetic method of N-(phenylpyruvoyl) amino acids. N-Hydroxy- or N-benzyloxy-Dl-alanine esters prepared from 2-bromopropionic esters and hydroxylamine or benzyloxyamine were treated with α-ethoxycinnamoyl chloride to give the corresponding N-(α-ethoxycinnamoyl) derivatives. Treatment of l-leucine ethyl ester with α-acetoxycinnamoyl chloride afforded N-(α-acetoxycinnamoyl)-l-leucine ethyl ester, the removal of the acetyl group from which was readily accomplished under mild, basic conditions, and N-(phenylpyruvoyl)-l-leucine ester was obtained. Treatment of the ester with ammonia yielded 3-benzylidene-6-isobutyl-2,5-piperazinedione.
α-乙氧基和α-乙酰氧基肉桂酰氯通过分别用亚硫酰氯和草酸酰氯处理α-乙氧基和α-乙酰氧基肉桂酸合成。为了寻找合成N-(苯基丙酮酰)氨基酸的方法,研究了氨基酸酯与肉桂酰氯的反应。从2-溴丙酸酯和羟胺或苄氧胺制备的N-羟基或N-苄氧基-Dl-丙氨酸酯与α-乙氧基肉桂酰氯反应,得到相应的N-(α-乙氧基肉桂酰)衍生物。将L-亮氨酸乙酯与α-乙酰氧基肉桂酰氯反应,得到N-(α-乙酰氧基肉桂酰)-L-亮氨酸乙酯,去除乙酰基在温和碱性条件下容易实现,得到N-(苯基丙酮酰)-L-亮氨酸酯。将该酯与氨反应生成3-苄亚甲基-6-异丁基-2,5-哌嗪二酮。