55115-08-7Relevant academic research and scientific papers
When hydrazonoyl chlorides meet terminal alkynes: Regioselective copper(I)-catalysed click sequential reactions to 5-substituted pyrazoles
Molteni, Giorgio
, p. 1249 - 1259 (2020/09/18)
In the presence of catalytic amounts of copper(I) salts, terminal alkynes underwent the formation of copper(I) acetylides that enabled their nucleophilic addition onto hydrazonoyl chlorides followed by spontaneous cyclisation of the resulting alkynylhydrazone intermediate. This sequential reaction sequence was exploited as a facile and regioselective synthesis of 1,3,5-substituted pyrazoles. A catalytic cycle has been proposed accounting for the observed results.
Rapid synthesis of tetrahydro-4H-pyrazolo[1,5-a]diazepine-2-carboxylate
Cvetovich, Raymond J.,Pipik, Brenda,Hartner, Frederick W.,Grabowski, Edward J.J.
, p. 5867 - 5870 (2007/10/03)
Hydrazines condense with dimethyl 2-pyrrolidino-4-oxo-2-pentenedioate in the presence of aq. HCl to form N-substituted pyrazole-3,5-dicarboxylates 2. Complex bicyclic derivatives, such as pyrazolo-oxazine 3a, pyrazolo-oxazepine 3b, pyrazolo-pyrazine 4a, and pyrazolo-diazepine 4b, were generated using 2-hydrazinoethanol, 3-hydrazinopropanol, 2-hydrazinoethylamine, and 3-hydrazinopropylamine.
