New Plant Growth Regulators of Benzimidazole Series

Introduction

Benzimidazole derivatives have a wide range of biological activity, including plant growth regulating activity. The study of the structure-activity relationship (SAR) in a number of benzimidazole derivatives is important for the development of new effective plant growth regulators. The design of new effective plant growth regulators based on these derivatives is an important scientific direction, as it is relevant for the development of agriculture, taking into account modern stringent environmental requirements.

Experimental

The reaction was monitored and the identification of the obtained compounds was determined by TLC, FTIR, NMR and XRD. The ¹H,¹³C NMR (400 MHz, 100 MHz, respectively), HMBC, HSQC, COSY spectra were obtained using a Varian 400 spectrometer. XRD of the single crystal of 2a was performed on an Xcalibur Ruby diffractometer.

Results and Discussion

A series of benzimidazole derivatives was synthesized (1-3a-c). The biological activity of the obtained compounds was carried out on wheat seeds. The results of studying the growth regulating activity of benzimidazole derivatives 1-3a-c showed that phenyl-substituted tricyclic benzopyrroloimidazolone 1a demonstrated the greatest effectiveness compared with the control (water) and the reference drug, indole-3-acetic acid (IAA).

It was found that the effectiveness of the compounds depends both on the structure of the molecule (cyclic or non-cyclic form) and on the steric volume of the side substituent and the volume of the molecule as a whole (the propionated molecule is sterically more voluminous than the original non-propionated one).