Boron-chelate assisted synthesis of di[pyrazol-3(5)-yl]methane and 1,1’,2,2’-tetra[pyrazol-3(5)-yl]ethane

A boron-chelate assisted methodology was applied to the synthesis of di[pyrazol-3(5)-yl]methane and 1,1’,2,2’-tetra[pyrazol-3(5)-yl]-ethane from acetylacetone or tetraacetylethane, N,N-dimethylformamide dimethyl acetal and hydrazine hydrate.