Transformations of phenylhydrazones of 5‐acyl‐1,2,4‐triazines to pyrazolo[4,3‐e][1,2,4]triazines or 4‐cyanopyrazole

Abstract

A simple and high yielding preparation of pyrazolo[4,3‐e][1,2,4]triazines and 4‐cyano‐3‐methyl‐1‐phenylpyrazole derivatives from corresponding phenylhydrazones of 5‐acyl‐1,2,4‐triazines by melt under acidic medium and by thermal heating, respectively.

The Anticancer Action of a Novel 1,2,4-Triazine Sulfonamide Derivative in Colon Cancer Cells

“…The starting material for the preparation of the new tricyclic sulfonamide MM131 was the corresponding chlorosulfone derivative 1 ( Scheme 1 ) which was obtained by multistage synthesis according to the procedures described in the literature [ 25 , 26 , 27 , 28 , 29 , 30 , 31 ]. Thus, obtained compound 1 was mixed with the ( R )-enantiomer of 2-amino-propan-1-ol in anhydrous acetonitrile at room temperature.…”

Synthesis of chiral pyrazolo[4,3-e][1,2,4]triazine sulfonamides with tyrosinase and urease inhibitory activity

“…Compound 3 was subjected to the reaction with methylhydrazine in the presence of acidic media according to standard procedure to give suitable hydrazone 4 as key intermediate for the preparation of 1 H -pyrazolo[4,3- e ][1,2,4]triazine derivative 5 . The hydrazone 4 could be converted into derivative 5 under conventional heating (10% HCl, EtOH, reflux, 1 h) 31 or under solvent free reaction conditions according to our previous published procedure 32 . Using Guillaumet and co-worker’s method 33 for the palladium-catalyzed cross-coupling reaction of 3-methylsulfanyl-1,2,4-triazine with boronic acid derivatives we have reacted 5-methylsulfanyl-1 H -pyrazolo[4,3- e ][1,2,4]triazines 5 with 2-ethoxyphenylboronic acid in the presence of copper (I) 3-methylsalicylate to obtain derivative 6 in excellent yield.…”

New pyrazolo[4,3-e][1,2,4]triazine sulfonamides as carbonic anhydrase inhibitors

“…In the beginning the known http://dx.doi.org/10.1016/j.bmc.2015.04.011 0968-0896/Ó 2015 Elsevier Ltd. All rights reserved. pyrazolo [4,3-e] [1,2,4]triazines 9a-f, prepared according to our previously developed procedure, 21 were subjected to the reaction with 2-ethoxyphenylboronic acid under Guillaumet's method 22 to produce corresponding derivatives 6a-f with the yield that strongly dependents on the kind of substituent on the aryl ring at the position N1 of this condensed ring system. The highest yield was observed for derivative 6c (93%) with para-methoxy group, and good yields were noticed for phenyl (62%) and para-tolyl group (71%).…”

“…Elemental compositions are within ±0.4% of the calculated values. Synthesis and spectroscopic data of derivatives 9a-f is described in our previous paper 21 and compounds 2-4 were prepared according to the literature procedure. 24 …”