4b
A series of chiral linear carboxamide derivatives (2- 15) with an incorporated peptide linkage have been prepared via the coupling of 1-ethyl-1,4-dihydro-7-methyl-4-oxo-quinoline-3-carboxylic acid (nalidixic acid, 1) with appropriate amino acid methyl esters. Coupling of 1 with amino acid methyl esters gave the corresponding peptide methyl esters 2, which were hydrolyzed with methanolic sodium hydroxide to the corresponding acids 3. Hydrazinolysis of esters 2with hydrazine hydrate afforded the corresponding acid hydrazide derivatives 4. The latter compounds were coupled with appropriate aldehydes or acetophenone derivatives to afford the corresponding Schiff base derivatives 5 and 6, respectively. The hydrazide derivative was reacted with phenyl isothiocyanate or carbonyl derivatives to give the corresponding thiosemicarbazide 7 and compounds 8- 10, respectively. Also, 4b was treated with acid monoanhydrides to give the corresponding imide derivatives 11- 13. Finally, 4b was reacted with tetracarboxylic acid dianhydride derivatives to afford the corresponding diimido carboxamide derivatives 14 and 15
4b
通过将 1-乙基-1,4-二氢-7-甲基-4-氧代-喹啉-3-羧酸(萘啶酸,1)与适当的氨基酸甲酯偶联,制备了一系列具有肽键的手性线性羧酰胺衍生物(2- 15)。1 与氨基酸甲酯偶联后得到相应的肽甲酯 2,用甲醇氢氧化钠将其水解为相应的酸 3。用肼水合物对酯 2 进行肼解,可得到相应的酸肼衍生物 4。后一种化合物与适当的醛或苯乙酮衍生物偶联,分别得到相应的希夫碱衍生物 5 和 6。酰肼衍生物与异硫氰酸苯酯或羰基衍生物反应,分别得到相应的硫代氨基甲酰肼 7 和化合物 8-10。此外,4b 与酸单酸酐处理后可得到相应的亚胺衍生物 11-13。最后,4b 与四羧酸二酐衍生物反应,得到相应的二亚氨基羧酰胺衍生物 14 和 15。