作者:N. Murthy Gandikota、R. Sekhar Bolla、I.V. Kasi Viswanath、Sridharreddy Bethi
DOI:10.14233/ajchem.2017.20624
日期:——
A facile synthesis for preparation of amide derivatives of [1,2,4]triazolo[4,3-a]pyridine can be achieved by the nucleophilic displacement of chloromethyl derivative with methyl amine followed by the reaction with acid analogues in the presence of 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate (HATU). Reaction of 2-chloropyridine with hydrazine hydrate (99 %) gave 2-hydrazinopyridine (2). Compound 3 was obtained in good yields by treating 2-hydrazinopyridine with chloroacetyl chloride. Further 3-chloromethyl-[1,2,4]triazolo[4,3-a]pyridine (4) is obtained by treatment of compound 3 with POCl3. Nucleophilic displacement of compound 4 with methyl amine gave methyl-[1,2,4]triazolo[4,3-a]pyridin-3-ylmethyl-amine (5). Finally protecting and deprotecting of compound 5 with Boc anhydride and HCl in dioxane gives hydrochloride salt of compound 5 i.e. (6) The reaction of hydrochloride salt of methyl-[1,2,4]triazolo[4,3-a]pyridin-3-ylmethyl-amine with 10 different acids yields amide analogues.
通过氯甲基衍生物的亲核取代反应和甲胺的反应,然后在1-[双(二甲基氨基)亚甲基]-1H-1,2,3-三唑并[4,5-b]吡啶-3-氧化物六氟磷酸酯(HATU)的存在下与酸类似物反应,可以实现[1,2,4]三唑并[4,3-a]吡啶酰胺衍生物的简易合成。2-氯吡啶与水合肼(99%)反应得到2-肼基吡啶(2)。用氯乙酰氯处理2-肼基吡啶可得到较高产率的化合物3。用POCl3处理化合物3可得到3-氯甲基-[1,2,4]三唑并[4,3-a]吡啶(4)。化合物4与甲胺发生亲核取代反应得到甲基-[1,2,4]三唑并[4,3-a]吡啶-3-基甲胺(5)。最后,用Boc酐和二氧六环中的HCl保护和脱保护化合物5,得到化合物5的盐酸盐,即(6)。甲基-[1,2,4]三唑并[4,3-a]吡啶-3-基甲胺的盐酸盐与10种不同的酸反应,生成酰胺类似物。