A novel synthesis of s-triazoloazines fused at the N2C3 bond of the triazole ring

N‐Acylhydrazines: Future Perspectives Offered by New Syntheses and Chemistry

“…The cyclisation of hydrazides to give heterocyclic compounds (mainly five-membered heterocyclic rings) is an important reactivity, but is not considered here because good reviews have already been published. [24]…”

Synthesis of Eosinophil Infiltration Inhibitors with Antihistaminic Activity.

“…When the Z group, which is a linker between the fused ring and a cyclic amine containing a benzhydryl group, is NH or NCH 3 , the compounds 5 and 6 were synthesized by a one-step condensation of azoles (1,2) and amines (3), or by a three-step sequence, i.e. amination of the azoles (1,2) with aminoalcohols (7), mesylation of the resulting alcohols (10a, b), and amination with cyclic amines (11). The compounds having an oxygen atom as a linker (5, 6; ZϭO) were synthesized by condensation of the azoles (1, 2) and alcohols (4) using a base.…”

“…The compounds having a sulfur atom as a linker (5, 6; ZϭS) were synthesized by the following method. The azoles (1,2) were treated with ethyl 3-mercaptopropionate in the presence of sodium methoxide to afford 6-azolylthiolates, which were alkylated with 1-bromo-3-halogenated propanes (8), and the resulting halides (10c, d) were condensed with the cyclic amines (11). Imidazo [1,2-b]pyridazine with a carbon side chain introduced directly at the 6-position (6; ZϭCH 2 ) was obtained by cross coupling of the azole (2) and an organo zinc reagent 8) in the presence of dichlorobis(triphenylphosphine)palladium(II), followed by alkylation of the cyclic amine (11) with the resulting halide (10e).…”

“…Other [1,2,4]triazolo [1,5b]pyridazines were prepared according to reported procedures. [10][11][12] Imidazo [1,2-b]pyridazines (2a-h) were synthesized as shown in Chart 4. Compound 12 was condensed with methyl 4-chloroacetoacetate (15), and alkylation of the resulting 2i gave dialkylated or cycloalkylated compounds (2a-c).…”

Synthesis of [1,2,3]triazolo[1,5-a][1,2,4]triazolo[5,1-c]pyrazines

“…We focused on the formation of 1,2,4-triazole ring fused to the N(5)=C(4)(NH 2 ) unit of the amine 1, 5 ( Figure 1), by the general synthetic method that use N,Ndimethylformamide dimethyl acetal (DMFDMA), hydroxylamine hydrochloride, and polyphosphoric acid (PPA) as the main required reagents, 7,8 thinking that this procedure could be extended to the heterocyclic system 1. …”