78830-54-3

Upstream product

• 78830-42-9 [(4S,5R)-5-Benzoyl-3-(4-nitro-phenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-4-yl]-phenyl-methanone 
• 20147-55-1 p-nitrobenzaldehyde phenylhydrazonoyl chloride 
• 98-86-2 acetophenone 
• 555-16-8 4-nitrobenzaldehdye 
• 100-63-0 phenylhydrazine 
• 1131-80-2 (E)-3-(N,N-dimethylamino)-1-phenyl-2-propen-1-one 
• 2829-27-8 4-nitro-benzaldehyde phenylhydrazone 
• 959-28-4 1,4-diphenylbut-2-ene-1,4-dione 

Relevant academic research and scientific papers

The use of enaminones and enamines as effective synthons for MSA-catalyzed regioselective synthesis of 1,3,4-tri- And 1,3,4,5-tetrasubstituted pyrazoles

In the present work, an efficient regioselective synthesis of 1,3,4-tri- and 1,3,4,5-tetrasubstituted pyrazoles via a methanesulfonic acid (MSA)-catalyzed reaction of hydrazones with enaminones or enamines is reported. Mechanistically, the formation of the title compounds involves the [2+3] cycloaddition of hydrazones with enaminones or enamines followed by aromatization with acid and oxygen. This convenient method under mild conditions with various hydrazones, enaminones, and enamines was well-tolerated to afford products in good to excellent yields. Compared with the literature methods, this strategy has advantages such as materials that are available economically, metal-free catalysis, excellent regioselectivity, and high efficiency.

The Cycloaddition of Nitrilimines with 1,2-Dibenzoylethylenes

The cycloaddition of nitrimines with 1,2-dibenzoylethylenes gave an unexpected 1,3-diaryl-4-benzoylpyrazole and benzoic acid, along with an expected cycloadduct, 1,3-diaryl-4,5-dibenzoyl-2-pyrazoline, and its dehydrogenated product, 1,3-diaryl-4,5-dibenzoylpyrazole.The elimination of the benzoyl group from the pyrazoline followed by dehydrogenation was shown to be the course of the unusual reaction.