Synthesis of 2-amino-4H-pyran and 2-benzylidene malononitrile derivatives using a basil seed as a cheap, natural, and biodegradable catalyst

Abstract

Developing green and sustainable principles in catalytic systems using natural materials is becoming a suitable strategy to reduce the possible pollutant with high-risk agents. This study introduces basil seed (Ocimum basilicum) as an efficient catalyst for the synthesis of 2-amino-4H-pyrans from aromatic aldehyde, malononitrile, and ethyl acetoacetate and 2-benzylidene malononitriles from aromatic aldehyde and malononitrile through the Knoevenagel condensation reaction in an aqueous medium at 80 ​°C and 50 ​°C, respectively. The prepared catalyst was characterized by FT-IR, XRD, SEM, EDS, BET, TGA, and Elemental mapping techniques, and its performance was evaluated in the synthesis of 2-benzylidene malononitriles and 2-amino-4H-pyrans. Indeed, the basil seed catalyst displays excellent catalytic activity (80–98%) and stability at the mentioned reactions. Furthermore, compared to other catalysts employed in these syntheses, the basil seed catalyst has properties that can outstand it as a catalyst. These attributes include easy separation, easy work manner, high efficiency, cost-effectiveness, reusability, and recyclability. Furthermore, this catalyst is entirely biodegradable, non-toxic, based on the green chemistry frameworks, and can be reused without a remarkable reduction in its catalytic activity.

Keywords

• Basil seed
• Knoevenagel reaction
• 2-Amino-4H-pyran
• Heterogeneous catalyst