Design and preparation of a new Ni/Arg@zeolite-Y nano-composite: investigation of its performance as a multi-functional and bio-organic catalyst for the one-pot synthesis of thieno[2,3- d]pyrimidinones

Abstract

This paper describes the design and fabrication of a Ni/Arg@zeolite-Y nanocomposite, and investigates its application as a multifunctional nanocatalyst in the one-pot synthesis of thieno[2,3-d]pyrimidinone derivatives. Herein, nickel metal ions were stabilized on NaY zeolite through a sodium exchange process (Ni@zeolite-Y). Then, this catalyst was functionalized via the linker 3-chloropropyltriethoxysilane with the basic l-arginine amino acid (Arg@zeolite-NiY). The structure of the nano-catalyst was confirmed using techniques such as FT-IR, XRD, BET, FE-SEM, TGA-DTA, and EDX-MAP. The catalytic activity of this nanocomposite in the green synthesis of thieno-pyrimidines was evaluated. Initially, the feasibility of conducting the reaction with this nano-catalyst was assessed through a one-pot reaction involving the cyclization of 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxamide with various aromatic aldehydes under different conditions. Subsequently, the reaction's generality for synthesizing thienopyrimidines under optimized conditions was successfully demonstrated. Key advantages of this project include the elimination of the toxic homogeneous catalyst hydrochloric acid and the use of green solvent ethanol. Additional benefits are the non-toxic nature, cost-effectiveness, recyclability of the nano-catalyst, ease of product isolation, high yield, and reduced reaction time.

Fig. 1. Frameworks of some thienopyrimidine-based drugs.

Scheme 1. The synthetic pathway of thieno[2,3-d]pyrimidinones using Ni/Arg@ZY.

Scheme 2. Synthesis pathway of the Arg@zeolite-NiY nanocatalyst.

Fig. 2. Comparison of the FT-IR spectra of zeolite-NaY, Ni@ZY, Ni/Pr–Cl@ZY, and Ni/Arg@ZY.

Fig. 3. Energy dispersive X-ray (EDX) analysis of the Ni/Arg@ZY nanocatalyst.

Fig. 4. Elemental distribution map (EDX-MAP) of elements in the Ni/Arg@ZY nanocatalyst.

Fig. 5. FE-SEM images of the samples: (a) zeolite-NaY, (b) Ni–ZY, and (c and d) of the Ni/Arg@ZY nanocatalyst.

Fig. 6. Histogram of particle size distribution in the Ni/Arg@ZY nanocatalyst.

Fig. 7. Adsorption–desorption isotherm curves for samples (a) zeolite NaY, Ni@ZY, and (b) Ni/Arg@ZY.

Fig. 8. Pore size distribution chart of the Ni–Arg@ZY nanocatalyst.

Fig. 9. Thermal stability curve (TGA–DTA) of the Ni–Arg@ZY nanocatalyst.

Fig. 10. XRD spectrum of Ni–Arg@ZY nanocatalyst.

Scheme 3. Synthesis route for the preparation of 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxamide (1).

Fig. 11. Reusability of Ni–Arg@ZY nanocatalyst for the model reaction.

Fig. 12. FT-IR spectra of the (a) Ni–Arg@ZY before the reaction and (b) after five cycles.

Scheme 4. The proposed mechanism for the preparation of thieno[2,3-d]pyrimidinones using Ni–Arg@ZY catalyst.