Synthesis of β-(N-1,2,3-Triazolyl)-Substituted α,β-Unsaturated α-Amino Acid Derivatives. A New Example of 1H- to 2H-1,2,3-Triazole Isomerisation

Synthesis of alkyl 2-benzoylamino-3-(4,5-dicyano-1H-imidazol-1-yl)propenoates

“…Compound 5 was prepared as described in the literature. 16 All other compounds were used without purification as obtained from commercial sources.…”

“…[13][14][15] In the course of our investigations of the use of diaminomaleonitrile in heterocyclic synthesis we reported a new approach to 1,2,3-triazol-1-yl-substituted unsaturated amino acid derivatives. 16 Attempts to prepare structurally similar imidazolyl amino esters 2 by treatment of propenoates 1 with triethyl orthoformate at reflux temperature failed, giving rise to highly functionalized imidazo [1,5- …”

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

“…This type of reaction, but with the two groups in the same ring, had been observed in some heterocycles, for example in 2-amino-3-cyanopyridine. 9,10 In addition, [1,2,3]triazoloazines with a bridgehead nitrogen atom exhibit valence tautomerism and could suffer lost of dinitrogen forming azine derivatives, via the corresponding diazomethylazines.…”

“…1,2 Recently we designed novel approaches to β-(1,2,3-triazol-1-yl)-α-amino acid derivatives, 3 β-(imidazol-1-yl)-α-amino acid derivatives, 4 As an extension of these investigations we describe here further functionalization of the [1,2,3]triazolo [1,5-a]pyrazine system and the synthesis of some [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.…”

A Novel Approach to Imidazo[1,5-a]pyrazines

“…3 Recently, we disclosed a novel approach to the a,b-unsaturated b-1H-1,2,3-triazol-1-yl substituted a-amino acid derivatives. 4 As a continuation of this research we describe herein a novel approach to the imidazo[1,5-a]pyrazine system.…”