Synthesis and Antimicrobial Activity of New Pyridothienopyrimidines and Pyridothienotriazines

Abstract

5‐Acetyl‐3‐amino‐4‐aryl‐6‐methylthieno[2,3‐b]pyridine‐2‐carboxamides (5a,b) were reacted with triethyl orthoformate or nitrous acid to give the corresponding pyrimidinones6a,b and triazinones 7a,b. The reaction of 5a,b with acetic anhydride was carried out and its products were identified as a mixture of 8‐acetyl‐9‐aryl‐2,7‐dimethylpyrido[3′,2′:4,5]thieno[3,2‐d]pyrimidine‐4(3H)‐one (9a,b) and related 5‐acetyl‐4‐aryl‐3‐biacetylamino‐6‐methylthieno[2,3‐b]pyridine‐2‐carbonitrile (10a,b). Reaction of 7a with some halocompounds afforded the N‐alkylated triazinones8a‐c. Chlorination of6a,b and 9a,b with phosphorus oxychloride produced 4‐chloropyrimidines 11a‐d which were used as precursors for the rest of the target heterocycles. Some of the prepared compounds were tested in vitro for their antimicrobial activities.

Synthesis and antifungal activity of novel polyheterocyclic compounds containing fused 1,2,4-triazine moiety

“…[26][27] On the other hand, compound 4 was also obtained using alternative pathways. Treatment of diamine 1 with hydrazine hydrate afforded 4-(4-chlorophenyl)-3,6,7-triamino-7H-pyrazolo [3,4-b]pyridine-5-carbonitrile (5). Heating an ethanolic solution of 5 with CS 2 /KOH at reflux yielded thioxopyrazolotriazolopyridine 6 which on methylation yielded the methylthio derivative 7.…”

“…[4][5][6] Triazolopyridines are also interesting compounds due to their pronounced biological activity, as they can be used as antidepressants. [7][8] Various 1,2,4-triazine derivatives are well known to possess an array of physiological activities, such as anticancer, muscle relaxant, hypnotic, anti-inflammatory, diuretic and antihypertensive activities.…”

Synthesis and Reactions of New Thienopyridines, Pyridothieniopyrimidines and Pyridothienotriazines

“…11 Moreover, some pyridothienotriazines are known to exhibit antianaphylactic, 12 and antiallergic activity. 13 In view of these facts and as a continuation of our previous work on thieno [2,3-b]pyridines, [14][15][16][17] we report herein the synthesis of the title compounds and their evaluation regarding antimicrobial activities.…”

Heterocyclic synthesis with 4-hydrazinopyridothienopyrimidines: Synthesis of pyridothienotriazolopyrimidines and heterocyclylpyridothienopyrimidines with biological interest

“…Furthermore, thienopyrimidines also exhibit different types of biological activity. A number of compounds of this class have been known to show antimicrobial [14][15][16] and antitumor [17] activities. Additionally, such a ring system has been used as antiprotozoals [18], intercalating nucleic acids [19], and phosphordiesterase IV inhibitors [20].…”