137527-44-7

Upstream product

• 137527-42-5 (E)-1-(1,3-dimethyl-5-hydroxy-4-pyrazolyl)-3-phenyl-2-propen-1-one 
• 4192-77-2 ethyl cinnamate 
• 2749-59-9 1,3-dimethyl-5-pyrazolone 
• 102-92-1 Cinnamoyl chloride 
• 5203-77-0 1,3-dimethyl-1H-pyrazol-5-ol 

Downstream Products

• 137527-45-8 5,6-dihydro-1,3-dimethyl-6-phenylpyrano<2,3-c>pyrazole 

Relevant academic research and scientific papers

New 1-substituted 4-cinnamoyl-5-hydroxypyrazoles and precursors thereof: Synthesis, ring closure reactions and NMR-spectroscopic investigations

Reaction of 1-substituted 5-hydroxy-1H-pyrazoles (pyrazolones) with trans-cinnamoyl chloride / calcium hydroxide in dioxane affords the corresponding 4-cinnamoyl-5-hydroxy-1H-pyrazoles. Cyclization of the latter into 5,6-dihydropyrano[2,3-c]pyrazol-4-ones proceeds in very low yields upon treatment with concentrated sulfuric acid. 1,6-Diphenyl-1H-pyrano[2,3-c]pyrazol-4-one was synthesized by reaction of of 4-acetyl-5-hydroxy-1-phenyl-1H-pyrazole with benzoyl chloride and lithium bis(trimethylsilyl)amide and subsequent cyclization of the thus obtained 1,3-diketone. NMR-spectroscopic investigations with the obtained 4-substituted 5-hydroxypyrazoles and their precursors regarding their tautomeric behavior in various solvents are presented.

Pyrazoles. 5. Novel Pyrazole Analogues of Flavanone, Flavone and Flavane

The synthesis of the new pyranopyrazole derivatives 4, 5, and 7 starting from (E)-1-(1,3-dimethyl-5-hydroxy-4-pyrazolyl)-3-phenyl-2-propen-1-one (2) is reported.