Pyrazolyl ethers, synthesis

The quantitative solid-state synthesis of the pyrazolyl ethers by ball milling of equimolar amounts of pyrazolone derivatives 1 with phenacyl bromide was achieved by Abdel-Latif and MetwaUy [1], In this procedure, it was unnecessary to use base catalysis, solvents, or liquid phases to obtain ether products 2a-c in 100% yield at room temperature after washing with sodium carbonate solution (Scheme 4.1). 0-alkylation of equimolar amounts of reagents was carried out in Retsch MM2000 swing mill in stainless steel lOmL vial and balls (2 x 12mm). 

The following reaction was reported by Abdel-Tatif and MetwaUy (07MC771). The quantitative solid-state synthesis of the pyrazolyl ethers 66 was achieved by ball milling an equimolar ratio of pyrazolone... 

Addition of hydrazines to 1,3-difunctional compounds is one of the most common methods employed for the preparation of pyrazoles. For example, several synthesis of pyrazoles have been reported where azide reagents are added to a,P-unsaturated systems. Reactions of trifluoroacetyl enol ether (thiophene) 1 with hydrazines afforded 3-(2-furyl) or 3-(2-thienyl)pyrazoles 2 <05S2744>. A regiospecific one-pot synthesis of trifluoromethyl-substituted heteroaryl pyrazolyl ketones has also been disclosed <05JHC631, 05JHC1055>. 1,3,5-... 

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