22717-41-5

Upstream product

• 85920-63-4 5-(1-hydroxyethylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione 
• 75-03-6 ethyl iodide 
• 100-63-0 phenylhydrazine 
• 607-97-6 ethyl 2-ethyl-3-oxobutanoate 
• 1694-31-1 tert-butyl acetoacetate 

Downstream Products

• 1310585-09-1 C₂₄H₂₆N₂O₄ 
• 1310584-87-2 C₂₅H₂₈N₂O₄ 
• 1360466-23-4 C₂₂H₂₁N₃O₃ 
• 1360466-30-3 C₂₉H₂₇N₃O₃ 
• 153787-26-9 4,4'-diethyl-5,5'-dimethyl-2,2'-diphenyl-2,2',4,4'-tetrahydro-3H,3'H-[4,4'-bipyrazole]-3,3'-dione 

Relevant academic research and scientific papers

Tunable Aerobic Oxidative Hydroxylation/Dehydrogenative Homocoupling of Pyrazol-5-ones under Transition-Metal-Free Conditions

A practical and tunable transition-metal-free aerobic oxidation of pyrazol-5-ones preparing either 4-hydroxypyrazoles (via C-H hydroxylation) or bispyrazoles (via dehydrogenative homocoupling) is described. The K2CO3/dioxane reagent system predominately promoted hydroxylation to deliver the α-hydroxylated pyrazoles. In contrast, the formation of bispyrazoles was overwhelmingly preferred with CH3CN as the reaction medium without any additives.

Microwave-assisted synthesis of substituted pyrazolones under solvent-free conditions

Condensation of hydrazine derivatives with various β-keto esters under solvent-free conditions using microwave irradiation leads to very rapid formation of pyrazolones with good to excellent yields.

Solid-phase synthesis of substituted pyrazolones from polymer-bound β-keto esters

Polymer-bound acetoacetate 3 was γ-mono- and γ-dialkylated, as well as α-monoalkylated, to give 6, 9, and 13, respectively. Treatment with hydrazine or substituted hydrazines followed by thermal or acidic cyclizing cleavage yielded the pyrazolones 17a-dd in a purity of >90%.

Solid-phase synthesis of polymer-bound β-ketoesters and their application in the synthesis of structurally diverse pyrazolones

An efficient solid-phase synthesis of different polymer-bound β-ketoesters 7 is described using readily available acid chlorides 1 and haloalkanes 6 as building blocks. The corresponding pyrazolones 9 and 10 were obtained by mild acid catalyzed reaction with phenylhydrazine or by treatment with hydrazine under cyclisation and cleavage from the resin in high purity and good yield.