Synthesis of tetra-substituted pyrazoles

A set of highly substituted pyrazoles bearing different functional groups on the pyrazole core was developed. Employing a suitable protecting group strategy we could regioselectively introduce various substituents in position 1, 3 and 4 of the pyrazole. This enabled the synthesis of various derivatives of a pyrazole–biscarboxamide with insecticidal activity. During the optimization process we focused on the precise exchange of carboxamide as well as other functional groups based on the concept of bioisosterism.