A convenient and efficient synthesis of a series of ethyl-1-(6-(4-substitutedacetylatedpiperazin-1-yl)pyrimidin-4-yl)-5-amino-1H-pyrazole-4-carboxylate (8a-8j) has been developed by five steps which include activation of a methylene group, hydrazinolysis, cyclisation and chloro-amine coupling reactions. Moreover, our proposed mechanism was confirmed in this study demonstrating that ethyl 5-amino-1-(6-chloropyrimidin-4-yl)-1H-pyrazole-4-carboxylate is the key intermediate to fulfill the desired outcomes. In silico and in vitro studies were carried out to identify the active agents among the developed adducts against mycobacterium tuberculosis (PDB ID:4TRO). Compound 8a (Docking Score: -26.81 and MIC: 1.6 ug/mL) was found to be the most potent among the synthesized molecules. All the synthesized compounds showed acceptable drug-like properties which make them suitable for further lead modification using in silico design approaches.

Pyrimidine compounds continue to attract great interest in the field of organic synthesis due to their various chemical and biological applications observed, especially in recent times. As a result, this review covering some periods from 1957 to 2021 has been prepared to discuss some of the structural pathways of these compounds as well as some of their interactions and applications.

Thiazolopyrimidnes are considered one of the most interesting classes in heterocyclic chemistry due to their pharmaceutical importance. Herein, we report the synthesis of some new heterocyclic compounds containing thiazolopyrimidine starting from compound (1) which was previously prepared in literature. The starting compound was allowed to react with different alkylating agents such as chloroacetone, chloroacetyl chloride, and phenacyl bromide to afford derivatives (2-4). Compound (5), benzylidene derivative, was obtained by the reaction of compound (2) with benzaldehyde while amino-dicarbonitrile compound (6) can be obtained by the reaction of compound (5) and malononitrile. Acetylation of amino group in compound (6) with chloroacetyl chloride led to formation of compound (7). Nucleophilic substitution of chlorine in compound (7) by aniline gave compound (8) which further subjected the Munich reaction to form compound (9). All new synthesized compounds were characterized using different elemental and spectral analysis.

A sequence of pyrano[2, 3-c]pyrazoles was constructed through promoting an eco-friendly, green, and efficient approach. M1-M25 derivatives were developed by a base-catalyzed one-pot reaction involving application of hydrazine hydrate 96%, β-keto ester as ethyl acetoacetate or diethyl malonate, aryl/heteroaryl aldehyde or isatin, and enolizable active methylene compounds with isolation of unexpected compound M2. Further on, intramolecular cyclization of compounds M10, M13 with formic acid, acetic anhydride, and formamide leads to the corresponding pyrimidine derivatives M26-M31. Afterwards, the antimicrobial activity of the compounds was evaluated and fortunately, the vast majority of the compounds showed outstanding anti-bacterial results. Besides, the potential mode of action of the synthesized compounds was determined by employing a molecular-docking study against penicillin-binding protein implicated in anti-bacterial action. Compound M21 was one of the most promising anti-bacterial agents with potential binding affinity against the penicillin-binding protein. This study shed light on novel compounds for further antimicrobial drug development.