Part-II: an update of Schiff bases synthesis and applications in medicinal chemistry-a patent review (2016-2023)

ABSTRACT

Introduction

Schiff bases are compounds with characteristic features of azomethine linkage (-C=N-). Schiff bases are capable of coordinating with metal ions via azomethine nitrogen. Schiff base derivatives and their metal complexes are known for intriguing novel therapeutic properties. In organic synthesis, the Schiff base reaction is prime in creating the C-N bond. Synthetic accessibility and structural diversity are the salient features for facile synthesis of Schiff base hybrids via a condensation reaction between an aldehyde/ketone and primary amines.

Area covered

This review aims to provide a comprehensive overview of the commendable medicinal applications of Schiff base derivatives and their metal complexes patented from 2016 to 2023.

Expert opinion

Schiff base derivatives are exceptional molecules for their assorted applications in medicinal chemistry. Several Schiff base products are marketed as drugs, and plenty of room is available for the purposive synthesis of new compounds in a diverse pool of disciplines. Expansion in the derivatization of Schiff bases in innumerable directions with multitudinous applications makes them ‘magical molecules.’ These compounds have proved extraordinary, from medicinal chemistry to other fields outside medicine. This review covers the therapeutic importance of Schiff base derivatives and aims to cover the patents published in recent years (2016–2023).

GRAPHICAL ABSTRACT

KEYWORDS:

• Schiff base
• metal complexes
• medicinal chemistry
• imine bond
• azomethine linkage
• biological activities

Article highlights

• Schiff bases are the condensation products of aldehydes/ketones and primary amines.

• The characteristic feature of Schiff bases, azomethine linkage, has played an important role in tagging biologically active aromatic/heterocyclic scaffolds to form diverse molecular hybrids.

• Perfectly tailored Schiff base derivatives are desirably well suited for their applications in various fields.

• Herein, we have reviewed Schiff base derivatives patented for their medicinal applications from 2016 to 2023.

Declaration of interests

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgments

The authors also acknowledge the financial support of the Pakistan Academy of Science, 3-Constitution Avenue, G-5/2, Islamabad-44000, Pakistan, under PAS Project No. 111.

Author contribution statement

Hafiza Amna Younus wrote the article; Faiza Saleem wrote and finalized the article; Abdul Hameed conceived the idea and performed the literature survey; Mariya al-Rashida organized and sorted out the literature; Muhammad Saeed supervised; Khalid Mohammed Khan supervised, provided critical feedback and finalized the article; Raed A. Al-Qawasmeh provided critical feedback; Mohamed El-Naggar provided critical feedback; Sobia Rana finalized the article.

Additional information

Funding

This paper was funded by the Pakistan Academy of Science, 3-Constitution Avenue, G-5/2, Islamabad-44000, Pakistan, under PAS Project No. 111.