A convenient method for the synthesis of DNA-recognizing polyamides in solution.

A convenient method for the synthesis of polyamides containing N-methylpyrrole (Py) and N-methylimidazole (Im) in solution has been developed. Most of the building blocks have been prepared by a haloform reaction in a simple way that column chromatography can be avoided. By use of the DCC/HOBT coupling reaction, the building blocks prepared have been effectively connected to construct a variety of subchains and polyamides without employing amino protection and deprotection. By use of the present method, an eight-ring polyamide, PyPyPyPygammaPyImImPybetaDp (gamma is gamma-aminobutyric acid, beta is beta-alanine, Dp is N, N-dimethylpropyldiamine), has been synthesized by the coupling of two four-ring subchains in one step.