74618-12-5

Upstream product

• 90-02-8 salicylaldehyde 
• 29978-83-4 o-propargyloxybenzaldehyde 
• 1576-35-8 toluene-4-sulfonic acid hydrazide 

Downstream Products

• 74618-08-9 2-(propargyloxy)-N'-acetyl-N'(p-toluenesulfonyl)-benzoylhydrazine 
• 65698-90-0 2-Phenyl-2,4-dihydrochromeno<4,3-c>pyrazol 
• 122835-22-7 2-(p-toluenesulfonyl)-2,4-dihydro⁽¹⁾benzopyrano(4,3-c)pyrazole 
• 104057-36-5 2-Phenyl-5-<2'-(2''-propinyloxy)phenyl>tetrazol 

Relevant academic research and scientific papers

1,3-Dipolar Cycloaddition of Alkyne-Tethered N-Tosylhydrazones: Synthesis of Fused Polycyclic Pyrazoles

A general and transition-metal-free access to the fused polycyclic pyrazoles via an intramolecular 1,3-dipolar cycloaddition reaction of alkyne-tethered tosylhydrazones has been reported. The pure solid products could be obtained without column chromatography in high to excellent yields, and the obtained products are useful bioactive molecules or could be used as the key intermediate for synthesis of these compounds in one or two steps. Additionally, a [3+2]-cycloaddition followed by a direct H-shift aromatization reaction mechanism was proposed, which is different from the previously reported aryl or alkyl sequential [1,5]-sigmatropic rearrangement pathway.

Unified Approach to Pyrazole-Fused Heterocyclic and Carbocyclic Motifs through One-Pot Condensation and Intramolecular Dipolar Cycloaddition Reaction

A one-pot synthesis of highly substituted pyrazoles that are fused to dihydrochromenes, dihydroquinolines and cyclopentane motifs, from readily available precursors is reported. The reaction involves conversion of alkyne-tethered aldehydes into the corresponding tosylhydrazones, base-mediated generation of diazo compounds, and subsequent intramolecular dipolar cycloaddition reaction. A range of internal and terminal alkynes as well as bromoalkyne compounds can be employed as the tethered dipolarophile to afford the corresponding cycloadducts.

(1)BENZOPYRANO(4,3-c)PYRAZOLES BY INTRAMOLECULAR NITRILE IMINE ADDITION TO ACETYLENES

2-Alkynyloxy-benzaldehydes 1 are obtained by alkylation of the corresponding salicylaldehydes either with p-toluenesulfonic acid propargylester or 1-acetoxy-4-chloro-but-2-yne.The aldehydes 1 are converted into the hydrazones 2 by reaction with p-toluenes

Intramolekulare 1,3-dipolare Cycloadditionen von Diarylnitriliminen aus 2,5-Diaryltetrazolen

Alkenyl-substituted diaryl-nitrile-imines - generated by photolysis or thermolysis of alkenyl-substituted 2,5-diaryl-tetrazoles - undergo a regioselective intramolecular cycloaddition to yield new heterocyclic compounds, e.g. fused 2-pyrazolines.Wit