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Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes.

ABSTRACT: We describe the synthesis of so far synthetically not accessible 3,6-substituted-4,6-dihydro-3H-pyrazolo[3,4-d][1,2,3]triazines as nitrogen-rich heterocycles. The target compounds were obtained in five steps, including an amidation and a cyclative cleavage reaction as key reaction steps. The introduction of two side chains allowed a variation of the pyrazolo[3,4-d][1,2,3]triazine core with commercially available building blocks, enabling the extension of the protocol to gain other derivatives straightforwardly. Attempts to synthesize 3,7-substituted-4,7-dihydro-3H-pyrazolo[3,4-d][1,2,3]triazines, the regioisomers of the successfully gained 3,6-substituted 4,6-dihydro-3H-pyrazolo[3,4-d][1,2,3]triazines, were not successful under similar conditions due to the higher stability of the triazene functionality in the regioisomeric precursors and thus, the failure of the removal of the protective group.

SUBMITTER: Wippert N

PROVIDER: S-EPMC8630434 | biostudies-literature | 2021

REPOSITORIES: biostudies-literature

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Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes.

Wippert Nicolai N Nieger Martin M Herlan Claudine C Jung Nicole N Bräse Stefan S

Beilstein journal of organic chemistry 20211122

We describe the synthesis of so far synthetically not accessible 3,6-substituted-4,6-dihydro-3H-pyrazolo[3,4-d][1,2,3]triazines as nitrogen-rich heterocycles. The target compounds were obtained in five steps, including an amidation and a cyclative cleavage reaction as key reaction steps. The introduction of two side chains allowed a variation of the pyrazolo[3,4-d][1,2,3]triazine core with commercially available building blocks, enabling the extension of the protocol to gain ...[more]

PMID: 34900007

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