Regioselective Enzyme-catalyzed Synthesis of Pyrazole-containing Podands

Abstract

Initial results are described about a new synthesis of a family of the acylic cation-complexing compounds named podands containing a pyrazole moiety as a part of the molecule. This synthesis was carried out by lipase-catalyzed transesterification of the corresponding pyrazole-3,5-dicarbethoxy derivative with di- and triethyleneglycol monomethylether; it afforded good yields and a high degree of regioselectivity in N-substituted pyrazoles where 3 and 5 positions are not equivalents. As an initial approach, a simpler model of transesterification with n-octanol was studied.