On triazoles XLIV [1]. synthesis of new ring systems containing imidazo[2′,1′:3,4] [1,2,4] triazolo [1,5‐a]pyrimidine and imidazo[1′,2′:2,3][1,2,4]triazolo[1,5‐a]pyrimidine skeleton

Abstract

Dedicated to Dr. János Császár on the occasion of his 70 th birthdayRing transformation of 2-cyanoimido-3-methyl-1,3-oxazolidine (10) yielded 5-amino-3-[N-(2-hydroxyethyl)-N-methyl]amino-1H-1,2,4-triazole (6) that was ring closed with different β-keto esters to 2-[N-(2hydroxyethyl)-N-methyl]amino-1,2,4-triazolo[1,5-a]pyrimidinones (4). Cyclisation of derivatives 4 led to imidazo[2',1':3,4][1,2,4]triazolo[1,5-a]pyrimidines (2) and imidazo[1',2':2,3][1,2,4]triazolo[1,5-a]pyrimidines (3) representing 10 novel ring systems. Besides spectroscopical evidence of structure of derivatives 2 and 3 X-ray diffraction analysis of derivative 2b was also performed.

Molecular and crystal structure of 5-amino-3-(N-p-methylbenzoyl-N-p-toluenesulfonyl)amino-1-phenyl-1,2,4-triazole

“…The bond length of C (3) -N (5) is 1.429 (2) (2) is 174.9° (178.4° [12]). It should be noted that in compound 2 the N (5) -S (1) bond length is greater than the length characteristic of N-acyl-N-tosylamino fragments (1.60-1.64 Å) [13].…”

“…3,5-Diamino-1-R-1,2,4-triazoles enter into the composition of medicinal preparations [1] and are used for obtaining substances possessing a wide spectrum of biological activity [2,3]. On acylating 5-amino-1-phenyl-3-p-toluenesulfonylamino-1,2,4-triazole (1) with p-methylbenzoyl chloride in acetonitrile in the presence of pyridine a compound is obtained which, on the basis of data of elemental analysis, IR and NMR spectroscopy, was assigned the structure of 5-amino-3-(N-p-methylbenzoyl-N-p-toluenesulfonyl)amino-1-phenyl-1,2,4-triazole (2) [4].…”