Uncatalyzed One-Pot Synthesis of Highly Substituted Pyridazines and Pyrazoline-Spirooxindoles via Domino SN/Condensation/Aza-ene Addition Cyclization Reaction Sequence
摘要:
A previously unknown class of highly substituted pyridazines and pyrazoline-spirooxinoles are easily prepared by an uncatalyzed one-pot three-component approach incorporating a domino SN/condensation/aza-ene addition cyclization reaction sequence. 1,1-Dihydrazino-2-nitroethylene (DHNE) which is generated in situ from the nudeophilic substitution (SN) reaction of hydrazine and 1,1-bis(methylthio)-2-nitroethylene (BMTNE), allowed to be condensed with active 1,2-dicarbonyl compounds followed by an intramolecular aza-ene addition cyclization to obtain the titled products depending on the type of 1,2-dicarbonyl. All reactions are easily performed and proceed with high efficiency under very simple and mild conditions without any catalyst and give good yields avoiding time-consuming, costly syntheses, and tedious workup and purification of products.
A Unique Approach to Catalyst-Free, One-Pot Synthesis of Spirooxindole-Pyrazolines
作者:Abdolali Alizadeh、Nasrin Zohreh
DOI:10.1055/s-0031-1290322
日期:2012.2
A pseudo-five-component synthesis of spirooxindole-pyrazolines via a one-pot and catalyst-free reaction under mild conditions is reported. The 1,1-bishydrazino-2-nitroethylene intermediate generated in situ from the addition of aqueous hydrazine to 1,1-bis(methylthio)-2-nitroethylene is trapped by two equivalents of isatin derivatives to obtain the title compounds. spirooxindole - isatin - spiropyrazole