A New Synthesis of Pyrazoles through a Lewis Acid Catalyzed Union of 3-Ethoxycyclobutanones with Monosubstituted Hydrazines
作者:Gang Shan、Pengfei Liu、Yu Rao
DOI:10.1021/ol2002682
日期:2011.4.1
A new efficient and convenient approach toward the synthesis of pyrazoles is described. Through a Lewis acid catalyzed union of 3-ethoxycyclobutanones with monosubstituted hydrazines, a variety of pyrazole derivatives were prepared readily at ambient temperature with complete regioselectivity.
Zinc-promoted cyclization of tosylhydrazones and 2-(dimethylamino)malononitrile: an efficient strategy for the synthesis of substituted 1-tosyl-1H-pyrazoles
A Zn(OTf)2-promoted cyclization reaction of tosylhydrazones with 2-(dimethylamino)malononitrile has been successfully developed providing an efficient strategy for the synthesis of substituted 1-tosyl-1H-pyrazoles.