Scalable preparation, characterization, and application of alkali-treated starch as a new organic base catalyst

Preparation, characterization, and application of alkali starch (AS) given by dry co-grinding of starch and alkali is described in this work. Grinding using a mortar (agate) and pestle or, more conveniently, a ball mill has been found to be satisfactory for the preparation of the AS. The AS products were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) and x-ray fluorescence (XRF) analyses. The base capacities of ASs were 4.25–4.45 mmol/g, respectively. AS is a low cost and easy to handle base catalyst that showed promising catalytic performance in the synthesis of a dihydroquinazoline-based antibacterial drug that involves tandem hydration or decarboxylative amidation, imination, and Aza-Michael reactions. [Display omitted] •Grinding by mortar-pestle or ball mill of starch and NaOH gives alkaline starch.•Solvent-free alkalization helps to much interaction of starch with NaOH.•The base capacity of alkaline starch (AS) is high to act as an alkali catalyst.•AS is a handlebar solid, low-cost anionic polymer, and reusable catalyst.•As shows a talented catalytic performance in synthesis of an antibacterial drug.