Syntheses of New Unsymmetrical 2,5-Disubstituted-1,3,4-oxadiazoles and 1,2,4-Triazolo[3,4-<i>b</i>]-1,3,4-thiadiazoles Bearing Thieno[2,3-<i>c</i>]pyrazolo Moiety
作者:Shivaraj P. Patil、Shrikant B. Kanawade、Dinesh C. Bhavsar、Prashant S. Nikam、Sachin A. Gangurde、Raghunath B. Toche
DOI:10.1002/jhet.1584
日期:2014.3
New series of (thieno[2,3‐c]pyrazolo‐5‐yl)‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazoles 10a, 10b, 10c and (thieno[2,3‐c]pyrazol‐5‐yl)‐1,3,4‐oxadiazol‐3(2H)‐yl)ethanones 6a, 6b, 6c has been synthesized from thieno[2,3‐c]pyrazole‐5‐carbohydrazide 3 by multistep reaction sequence. (5‐Aryl‐1,3,4‐oxadiazol‐2‐yl)‐1H‐thieno[2,3‐c]pyrazoles 4a, 4b, 4c were also synthesized from thieno[2,3‐c]pyrazole‐5‐carbohydrazide
(thieno [2,3 - c ] pyrazolo-5-yl)-[1,2,4] triazolo [3,4- b ] [1,3,4]噻二唑10a,10b,10c和(thieno [2,3 - c ]吡唑-5-基)-1,3,4-恶二唑-3(2H)-基)乙炔6a,6b,6c是由噻吩[2,3 - c ]吡唑-5合成的碳酰肼3按多步反应顺序进行。(5-芳基-1,3,4-恶二唑-2-基)-1H-噻吩并[2,3- c ]吡唑4a,4b,4c也由噻吩并[2,3 - c ]吡唑-5-碳酰肼3通过与各种芳族羧酸环化。噻吩[2,3 - c ]吡唑-5-羧酸酯2与水合肼反应可得到酰肼3,产率高,化合物2通过5-氯-3-3-甲基-1-苯基-苯胺反应可制得化合物2。在乙醇酸钠存在下1H-吡唑-4-甲醛1和2-乙基硫代乙醇酸收率高。