In step with the development of organic chemistry, heterocyclic compounds play an important part. Electron-rich nitrogen containing heterocyclic compounds and their derivatives play key role in diverse biological activities. The wide-ranging functionality and stereochemical complexity in a five-member ring structure is shown by the pyrazole nucleus, which has two nitrogen atoms and exhibit aromatic character. The medicinal chemists have been using the relationship between chemical structure and biological activity of a molecule in drug discovery as the driving force to guide synthetic efforts, to design new chemical derivatives. It has been reported that pyrazoline derivatives possess a broad spectrum of biological activities such as antibacterial, antimicrobial, anti-inflammatory, antioxidant, antidiabetic, anticancer, antifungal, antitubercular, antidepressant, anticonvulsant and analgesic activities. They also possess some potent receptor selective biological activities like monoamine oxidases (MAOs) inhibitor, Nitric oxide synthase (NOS) inhibitor, Angiotensin converting enzyme (ACE) inhibitor, cholecystokinin-1 receptor antagonist and estrogen receptor (ER) ligand activity. Hence in this article, we focus on the pyrazole derivatives having heteroaryl substituents and their pharmacological activities along with their structure–activity relationships in order to create opportunities to explore the full potential of these compounds.
Keywords: Heterocyclic compounds, Pyrazolines, Claisen-Schmidt condensation, Chalcone.