1233979-75-3

Upstream product

• 501357-62-6 2-bromo-1-(6-bromobenzo[d][1,3]-dioxol-5-yl)ethan-1-one 
• 1576-35-8 toluene-4-sulfonic acid hydrazide 
• 71095-26-6 1-(2′-bromo-4′,5′-methylenedioxyphenyl)ethan-1-one 
• 71095-27-7 1-(2′-bromo-4′,5′-methylenedioxyphenyl)ethan-1-ol 
• 15930-53-7 6-bromo-3,4-methylenedioxybenzaldehyde 

Downstream Products

• 1233979-81-1 3-methyl-1-(p-tolylsulfonyl)-[1,3]dioxolo[4,5-f]indazole 

Relevant academic research and scientific papers

Base-catalyzed synthesis of substituted indazoles under mild, transition-metal-free conditions

Back to basics: A transition-metal-free method developed for the synthesis of indazoles involves an inexpensive catalytic system composed of a diamine and K2CO3. Various (Z)-2-bromoacetophenone tosylhydrazones were converted into indazoles at room temperature in excellent yields (see example; Ts=p-toluenesulfonyl). The yield was improved by photoisomerization with UV light when E/Z isomeric mixtures of the starting material were used. Copyright

Z-Selective synthesis of o-bromoacetophenone N-tosylhydrazones and formation of 3-methylindazoles in aqueous ethanol

A practical and effective Z-selective synthesis of o-bromoacetophenone N-tosylhydrazones is developed. Subsequent cyclization of Z-tosylhydrazones to furnish 3-methylindazoles is accomplished with the aid of copper and DMEDA in aqueous ethanol. Cyclization reactions are complete at ambient temperature in 10 min to afford the desired compounds in excellent yields.