Synthesis of New Derivatives of Pyridazino[6,1-c]Pyrimido[5,4-e][1,2,4]Triazine; a Novel Heterocyclic System

Abstract

Several derivatives of the novel pyridazino[6,1-c]pyrimido[5,4-e][1,2,4]triazine ring system have been synthesised through heterocyclisation of 5-bromo-2,4-dichloro-6-methylpyrimidine with 3-chloro-6-hydrazinylpyridazine followed by treatment with secondary amines in boiling ethanol.

Synthesis, Characterisation, and in Vitro Antibacterial Evaluation of a New Class of 2-substituted-4-methyl-7,8-dihydro-5H-pyrimido[4,5-d]thiazolo[3,2-a] Pyrimidines

“…the related pyrimido [4,5-d]pyrimidine derivatives after the elimination of dimethylamine from the cycloadducts as well as the oxidative aromatisation. 17 In view of these observations and in continuation of our study on fused pyrimidines, [18][19][20][21] we have undertaken the synthesis of some new derivatives of pyrimido [4,5-d]thiazolo [3,2-a] pyrimidine and tested their antibacterial activity.…”

Synthesis and Density Functional Theory Study of [1,2,3]Triazolo[4,5-d][1,2,4] Triazolo[4,3-a]Pyrimidine Derivatives: A Novel Heterocyclic System

“…[17][18][19] Some recently published protocols for assembling this bicyclic system have been accomplished through a one-pot multicomponent reaction using substituted aromatic aldehydes, malononitrile and 3-amino-1,2,4-triazole catalysed by boric acid in aqueous micellar conditions, 20 oxidative cyclisation of 4-amino-6-arylidene(heteroarylmethylidene) hydrazinyl-1,3,5-triazin-2-ones with Pb(OAc) 4 via a Dimroth-type rearrangement, 21 treatment of chloro-5,6diaminopyrimidines with NaNO 2 /HCl 22 and cyclisation of diethyl 2,4,6-trifluorophenylmalonate with 3-amino-1,2,4triazole. 11 Regarding these points, and due to our interest in the synthesis of various fused heterocyclic derivatives with a pyrimidine core, [23][24][25][26][27][28] herein we wish to report a convenient method for…”