5‐Amino‐2‐(p‐tolylamino)‐4‐phenylthieno[2,3‐d]pyrimidine‐6‐carbonitrile 9, which was synthesized by an innovative method, was used as a versatile precursor for synthesizing pyrimido‐thienopyrimidine, triazolopyrimidothienopyrimidine, and pyrimidothienotriazine compounds. Thus, reaction of aminothienopyrimidinecarbonitrile 9 with chloroacetylchloride in dioxane afforded the chloroacetylaminocarbonitrile derivative 10, which underwent nucleophilic substitution reactions with various primary and secondary amines gave the corresponding N‐alkyl‐(aryl)amino acetamides 11a,b. On the other hand, the reaction of aminocarbonitrile 9 with triethyl orthoformate followed by cyclization with hydrazine yielded an aminoiminopyrimidine derivative 13. The latter was used as versatile precursor for synthesis of new heterocyclic compounds. The structures of all the new compounds have been established on the basis of their analytical and spectral data (IR, 1H NMR, 13C NMR, and MS). Some of the synthesized compounds were evaluated in vitro for their anti‐inflammatory activity. All the tested compounds exhibited remarkable anti‐inflammatory activity.

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Oxygen-containing heterocycles are largely distributed in natural and synthetic compounds. Coumarins are among the most famous heterocycles which possess one oxygen atom in their rings. Coumarins are classified as multifunctional scaffold and are used as anti-oxidant reagents, anti-inflammatory, anti-microbial, anti-fungal, anti-HIV active, analgesic, anti-histaminic, insecticides, dyes, herbicides, sensitizers, perfumes, cosmetics and food additives. Due to their diverse applications in industrial and pharmaceutical fields, many chemists have given significant interest to these compounds. Herein, the review highlights various methods for the synthesis and interactions of coumarin moiety as one of the most efficient categories of heterocycles.

Biocompatible luminogens with aggregation-induced emission (AIE) have several applications in the biology field, such as in detecting biomacromolecules bioprobes and in bio-imaging. Due to their bioactivities and light-emitting properties, many heterocyclic compounds are good candidates for such applications. However, heterocyclic π-conjugated systems with AIE behavior remain rare as strong intermolecular π–π interactions usually quench their emission. In this work, new thienopyrimidine heterocyclic compounds were synthesized and their structures were verified by elemental analysis and Fourier transform infrared (FT-IR), 1H nuclear magnetic resonance (NMR), and 13C NMR spectra. The photophysical properties of some compounds were investigated in the solution and solid states. Density functional theory calculations were also performed to confirm the observed photophysical properties of the compounds. The studied dyes displayed AIE properties with spectral shapes related to the aggregate structure and a quantum yield up to 10.8%. The emission efficiency of the powder is attributed to the incorporation of multiply rotatable and twisted aryl groups to the fused heterocyclic moieties. The dyes also showed high thermal stability and potent antimicrobial activities against numerous bacterial and fungal strains. Additionally, the cytotoxicity of the new compounds was evaluated against the Caco-2 cell line, and molecular docking was used to investigate the binding conformation of the most effective compound with the MNK2 enzyme. Therefore, the presented structures may potentially be used for bioapplications.

Pyrimidine and thienopyrimidine derivatives play a very important role in organic chemistry because of their wide applications as bioactive compounds with multiple biological activities. However, a literature survey revealed that the merger of different groups in the thieno[2,3-d]pyrimidine heterocyclic ring enhances its antibacterial, antifungal and anti-inflammatory activities. This encouraged us to prepare a new series of thieno[2,3-d]pyrimidine heterocyclic compounds and to test them as antimicrobial and anti-inflammatory agents. These compounds have shown remarkable activity toward fungi, bacteria, and inflammation. Thus, these compounds have been prepared by the chloroacylation of 5-amino-4-phenyl-2-(p-tolylamino) thieno[2,3-d] pyrimidine-6-carboxamide (4) using chloroacetyl chloride under neat condition to afford the target compound (6), which was used as precursor for the synthesis of a number of bioactive compounds. Thus reaction of the chloromethylpyrimidine derivative (6) with triphenylphosphine in dry benzene gave the corresponding ((4-oxo-9-phenyl-7-(p-tolylamino)-3,4-dihydropyrimido[4 0 ,5 0 :4,5]thieno [2,3-d]pyrimidin-2-yl)methyl) triphenylphosphonium chloride (7). Compounds 8a-8c and 9a-9c were obtained by the reaction of 7 with some selected aromatic aldehydes and ketones in methanol and sodium methoxide under Wittig reaction condition. The structures of the all new synthesized compounds were established on the basis of their analytical and spectral data (IR, 1 H NMR, 13 C NMR, and MS).