438193-60-3

Upstream product

• 384339-31-5 3-bromo-2-(4-methoxybenzyl)pyrazole 1-oxide 
• 696-62-8 para-iodoanisole 
• 438193-56-7 3-bromo-2-(4-methoxybenzyl)-5-(4-methoxyphenyl)pyrazole 1-oxide 
• 384339-33-7 3-(4-methoxyphenyl)-2-(4-methoxybenzyl)pyrazole-1-oxide 

Downstream Products

• 438193-78-3 3,5-bis(4-methoxyphenyl)-1-hydroxypyrazole 

Relevant academic research and scientific papers

Sequential functionalization of pyrazole 1-oxides via regioselective metalation: Synthesis of 3,4,5-trisubstituted 1-hydroxypyrazoles

A range of 3,5-diarylated and 3,4,5-triarylated 2-(4-methoxybenzyl)pyrazole 1-oxides have been prepared by regioselective deprotonation at C-5 or bromine-magnesium exchange at C-3 or C-4 followed by transmetalation with ZnCl2 and palladium(0)-catalyzed cross-coupling. Furthermore, the metalated pyrazole 1-oxides could be trapped with electrophiles. The sequential metalation/functionalization of the pyrazole 1-oxides may follow the order C-5, C-3, C-4, or alternatively the order C-3, C-5, C-4. The 4-methoxybenzyl group of the functionalized 2-(4-methoxybenzyl)pyrazole 1-oxides could be removed by treatment with TFA and i-Pr3SiH in CH2Cl2, providing the corresponding functionalized 1-hydroxypyrazoles.