21673-04-1

Usage

Synthesis Reference(s)

Tetrahedron Letters, 25, p. 433, 1984 DOI: 10.1016/S0040-4039(00)99904-0

Upstream product

• 186581-53-3 diazomethane 
• 4360-47-8 cinnamonitrile 
• 2700-22-3 Benzylidenemalononitrile 
• 1563174-84-4 4-phenyl-3-tosyl-1H-pyrazole-5-carbonitrile 
• 119672-19-4 α-benzenesulfonyl-cinnamonitrile 
• 13138-21-1 diazoacetonitrile 
• 102-96-5 (2-nitroethenyl)benzene 
• 96256-53-0 4-phenyl-3-(trifluoromethyl)-1H-pyrazole 
• 89864-91-5 3-cyano-4-phenyl-5-trimethylsilylpyrazole 

Downstream Products

• 1189342-75-3 1-(2-oxo-2-phenylethyl)-4-phenyl-1H-pyrazole-5-carbonitrile 
• 1189342-77-5 1-(4-methylphenylsulfonyl)-4-phenyl-1H-pyrazole-5-carbonitrile 
• 1189342-72-0 1-(oxiran-2-ylmethyl)-4-phenyl-1H-pyrazole-5-carbonitrile 

Relevant academic research and scientific papers

Transition-Metal-Free [3 + 2] Cycloaddition of Nitroolefins and Diazoacetonitrile: A Facile Access to Multisubstituted Cyanopyrazoles

A transition-metal-free [3 + 2] cycloaddition reaction between nitroolefins and diazoacetonitrile (N2CHCN) is described. This protocol exhibits several merits including simple starting materials, mild reaction conditions, broad substrate scope, good yields, and regioselectivities. The one-pot three-component reaction of nitroolefins with diazoacetonitrile (N2CHCN) and alkyl halides is also developed, thus delivering a series of multisubstituted cyanopyrazoles in good to high yields.

Reactions of vinyl sulfone with α-diazo-β-ketosulfone and Bestmann-Ohira reagent for the regioselective synthesis of highly functionalized pyrazoles

The 1,3-dipolar cycloaddition of diazomethylsulfone anion, generated in situ from α-diazo-β-ketosulfone, with vinyl sulfone proceeds in a regioselective manner to provide sulfonylpyrazoles. Similar reaction of diazomethylphosphonate anion, derived from Bestmann-Ohira reagent, with vinyl sulfone leads to phosphonylpyrazoles. The sulfonyl group of vinyl sulfone undergoes chemoselective elimination in these reactions.

Synthesis of 3-cyanopyrazoles from 3-trifluoromethyl-pyrazoles via direct ammonolysis reaction

A simple and green method to prepare 3-cyanopyrazoles in aqueous ammonia from easy-obtained 3-trifluoromethyl-pyrazoles was explored. Most substrates got acceptable yields. The hydrogen position of N1-H on cyanopyrazoles was assigned by X-ray crystal structure analysis.

NEW METHODS AND REAGENTS IN ORGANIC SYNTHESIS. 41. LITHIUM TRIMETHYLSILYLDIAZOMETHANE. A NEW SYNTHON FOR THE PREPARATION OF PYRAZOLES FROM α,β-UNSATURATED NITRILES

Lithium trimethylsilyldiazomethane reacts smoothly with various α,β-unsaturated nitriles to give 3(or 5)-trimethylsilylpyrazoles in good yields.