90012-56-9Relevant academic research and scientific papers
Selective synthesis of functionalized pyrazoles from 5-amino-1H-pyrazole-4-carbaldehydes with sodium nitrite: 5-Amino-4-nitrosopyrazoles and pyrazole-4-carbaldehydes
Hsiao, Rong-Hong,Tseng, Ching-Chun,Xie, Jia-Jun,Tsai, Shuo-En,Uramaru,Lin, Ching-Ya,Chern, Ching-Yuh,Wong, Fung Fuh
supporting information, p. 4561 - 4569 (2019/07/10)
A novel and efficient redox reaction was developed to react 5-amino-1H-pyrazole-4-carbaldehyde with sodium nitrite (NaNO2) in an acidic solution (HCl/MeOH) to generate 5-amino-4-nitrosopyrazole, pyrazole-4-carbaldehyde, or diazenylpyrazole selectively. The results showed that 5-amino-4-nitrosopyrazoles were formed as the major product in the diluted acidic solution (≤2 N HCl in MeOH solution) through redox, formylation, and nitrosation reactions of NaNO2. Intriguingly, pyrazole-4-carbaldehyde was the main product under 6 N HCl in MeOH solution.
Cyclization of 4,5-diamino pyrazole derivatives and their antibacterial activities
Rizk, Hala F.,Ei-Badawi, Mahmoud A.,Ibrahim, Seham A.,Ei-Borai, Mohamed A.
experimental part, p. 1451 - 1459 (2011/10/30)
A convenient synthesis of intermediate 4,5-diamino-3-aryl-1-phenylpyrazoles 4a-4c was reported. The different cyclization reactions were carried out with chalcone, 2-mercaptoacetic acid and p-anisialdehyde, ethyl chloroformate, glyoxal and thiourea to afford different N and S containing heterocycles. The reaction conditions were compared by conventional heating and microwave irradiation. The structures of the cyclization products were determined by analytical and spectroscopic data. All the synthesized compounds were screened for antibacterial activities in vitro. Copyright
