(S)-3-(Dimethylamino)methylidene-5-benzyltetramic acid derivatives 4a and 4b were prepared in three steps from N-protected (S)-3-phenylalanines 1a and 1b, respectively. Similarly, N-[N-(benzyloxycarbonyl)glycyl]glycine (1c) was transformed into the enaminone 4c. Acid-catalysed coupling of enaminones 4a-c with aliphatic, aromatic, and heteroaromatic primary amines 5-34 afforded the corresponding N(3′)-substituted 3-aminomethylidenetetramic acid derivatives 35-64 in 29-96% yields.
(S)-3-(
二甲氨基)亚甲基-5-苄基四
环酸衍
生物4a和4b分别通过三步从N-保护的(S)-3-苯丙
氨酸1a和1b制备得到。类似地,N-[N-(苄氧羰基)甘
氨酰]甘
氨酸(1c)被转化为烯胺酮4c。烯胺酮4a-c与脂肪族、芳香族和杂芳香族一级胺5-34的酸性催化偶联反应,以29-96%的产率得到了相应的N(3′)-取代的3-
氨基亚甲基四
环酸衍
生物35-64。