Synthesis of N-(2-vinyloxyethyl)pyrazoles

Abstract

Alkylation of pyrazoles with 2,2`-dichloroethyl ether under conditions of phase-transfer catalysis was studied. The monoalkylation products of 3(5)-methylpyrazoles at 1903200oC undergo intramolecular cyclization to form bicyclic salts. Conditions for dehydrochlorination of N-[2-(2`-chloroethoxy)ethyl]pyrazoles into N-(2-vinyloxyethyl)pyrazoles were found.

10.1007/s11176-008-1023-0

“…Analogous relation was observed previously in the alkylation of pyrazoles with dichloroethane and dibromoethane [5,6]. The alkylation with equimolar amounts of the reactants was characterized by poor yields (203 40%) of alkylated products IV3VI due to concurrent dehydrochlorination of 2-chloroethylamine, and the yield considerably decreased in going from pyrazole (I) to 3,5-dimethylpyrazole (III).…”

Zwitterionic Ni(ii) complexes bearing pyrazolyl-ether-imidazolium ligands: synthesis, structural characterization and use in ethylene oligomerization

“…1-(2-(2-Chloroethoxy)ethyl)-3,5-dimethyl-1H-pyrazole was prepared by following literature procedures. 26 The ionic liquid [Bmim]Á[AlCl 4 ] was obtained by reacting 1-n-butyl-3-methylimidazolium chloride ([Bmim]Cl) with aluminum chloride, as described in the literature. 27 MAO (AXION s CA 1310, 10 wt% solution in toluene) was used as received.…”