A simple one-pot protocol is described for the synthesis of dispiro[fluorene-9,3′-pyrazole-5′,4″-pyrazolidines] via a [3 + 2] cycloaddition reaction between 9-diazo-9H-fluorene (DF) and a series of (E/Z)-4-arylidene-1-phenylpyrazolidine-3,5-diones (APPs). In all cases, the cycloaddition proceeds with complete regioselectivity, affording a single regioisomeric framework as a pair of diastereomers through an endo approach. The structures and regiochemical outcomes of the cycloadducts were established by comprehensive 1D and 2D NMR spectroscopic analyses (¹H, ¹³C, DEPT-135, COSY, ¹H-HSQC, HMBC, and ROESY). The regiochemistry and mechanism of the cycloaddition reaction were investigated using density functional theory (DFT) calculations at the B3LYP/cc-pVTZ level of theory, supported by analysis of global and dual local electrophilicity and nucleophilicity descriptors. To rationalize the observed stereoselectivity, the relevant transition-state structures were located and optimized using a QST3-based transition-state search at the same level of theory. Global electron density transfer (GEDT) analysis revealed that the cycloaddition reactions are highly polar, with electron density flowing from 9-diazo-9H-fluorene (DF) toward the (E/Z)-4-arylidene-1-phenylpyrazolidine-3,5-dione (APP) framework. Consistently, molecular electrostatic potential surface (MESP) analysis showed that, in the energetically favored transition states, the reacting partners approach through regions of opposite electrostatic potential, leading to stabilizing electrostatic interactions between the two fragments. The computational results are consistent with the experimental observations and support a polar, synchronous one-step cycloaddition mechanism. The developed protocol affords the desired dispiro compounds in good to excellent yields (59–91%) with complete regioselectivity, providing a single regioisomeric framework as a pair of diastereomers. This work provides valuable insights into diazo-based cycloaddition chemistry and is expected to stimulate further research in the synthesis of structurally complex spiroheterocycles. Compared to previously reported approaches, the present method offers a simple one-pot strategy with high efficiency, complete regioselectivity, and operational simplicity.

Acetylation of 1-amino-5-(piperidin-1-yl)-N-phenyl-6,7,8,9-tetrahydrothieno[2,3-c]isoquinoline-2-carboxamide (3) with acetic anhydride afforded unexpected [1,3]oxazinothienoisoquinolinone derivative in an excellent yield instead of the expected N-phenylpyrimidothienoisoquinolinone. Diazotization of 3 using sodium nitrite in acetic acid and sulfuric acid yielded the corresponding triazinothienoisoquinoline, while the reaction with triethyl orthoformate in acetic acid produced N-phenylpyrimidine derivative 7. Chloroacetylation of compound 3 with chloroacetyl chloride in dioxane at 60–70°C yielded chloroacetamido compound 8, which underwent ring closure upon reflux in acetic anhydride to produce the chloromethyl oxazinone derivative 9. Oxazinone derivatives 5 and 9 underwent nucleophilic substitution upon treatment with ammonium acetate/acetic acid mixture and hydrazine hydrate to afford pyrimidinone …

This study investigated the insecticidal bioefficacy of seven compounds (1-7) against maize aphid (Rhopalosiphum maidis). Results indicated that LC₅₀ values ranged from 1.52 to 18.45 mg/L for nymphs and 23.96 to 80.73 mg/L for adults. Compound (6) demonstrated the highest potency, with LC₅₀ values of 1.52 mg/L against nymphs and 23.96 mg/L against adults, establishing it as the most effective analogue for potential aphid control. The other compounds also exhibited varying degrees of insecticidal activity. For nymphs, compound (5) was notably effective, followed by compound (7), and compound (3) with LC₅₀ values of 2.23, 2.37, and 2.45 mg/L, respectively, indicating their promising potential. Compounds (4), (2), and (1) showed comparatively lower efficacy against nymphs with LC₅₀ values of 12.19, 14.14, and 18.45 mg/L, respectively. Similarly, for adults of maize aphids, compounds (5), (7), and (3 …

Two novel polyamides, Poly(Oxa) and Poly(Pip), were successfully synthesized through the polycondensation of 1,4-bis(2-chloroacetamido)benzene with either 5,5′-(1,4-phenylene)bis(1,3,4-oxadiazole-2-thiol) or piperazine, respectively. Comprehensive computational, structural, morphological, thermal, and photophysical analyses revealed distinct structure–property relationships governed by the nature of the polymer backbone. Poly(Oxa), containing a heteroaromatic framework, exhibited pronounced conjugation and semi-crystallinity, confirmed by FT-IR and XRD analyses. This architecture imparted exceptional thermal stability (char yield: 42.4 %), high flame retardancy (LOI = 34.5 %), and a heterogeneous morphology with strong π–π stacking interactions, which enhanced methylene blue adsorption. Remarkably, Poly(Oxa) displayed excitation-dependent photoluminescence, shifting from deep-blue to …

In this paper, new thieno[2,3-d]pyrimidine analogs have been synthesized and characterized through different spectroscopic techniques. The photophysical properties of the molecules (7b-7f) and the quantum chemical calculations have been investigated. These molecules exhibited aggregation-induced emission behavior and showed efficient emission in both solid and solution states. A shift toward shorter wavelengths (hypsochromic shift) was observed when transitioning from the solution to the solid state, which could be explained by photoinduced intramolecular charge transfer (ICT) processes. DFT calculations confirmed that the diverse behavior of the thieno[2,3-d]pyrimidine analogs could be attributed to variations in molecular packing and rigidity. This study illustrates how luminophores aggregation can occur without significantly impacting the excited state, emphasizing the unconventional behavior …

This study presents the efficient synthesis of a novel series of pyrazole-thiosemicarbazone derivatives (3-7) from a key precursor (2) via cyclization with α-halocarbonyl compounds. The structures of all synthesized hybrids were unequivocally confirmed through elemental analysis and comprehensive spectral studies (IR, NMR, MS). Among them, in vivo anti-inflammatory evaluation in a carrageenan-induced paw edema model identified compounds 3 and 4 as exceptionally potent, exhibiting significant inhibition rates of 66.67% and 73.08%, respectively. Molecular docking studies revealed strong and favorable binding interactions of these lead compounds with the active sites of cyclooxygenase enzymes (COX-1 and COX-2), providing a rational structural basis for their observed efficacy. Furthermore, in silico pharmacokinetic predictions indicated that 3 and 4 possess promising drug-likeness and oral bioavailability …

Thienopyridines one of the most important classes in organic chemistry due to their outstanding medicinal and environmental applications. In this study, we report the synthesis of a series of novel thienopyridine derivatives bearing different aryl substituents on the fused thiophene moiety to showcase their inhibition behavior on different strains of bacteria and Fungai which can further be evidenced by molecular docking. The 4,6-dimethyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile (3) was used as a starting material for the synthesis of the target compounds (4-15). The condensation of compound 3 with thiophene-2-carbaldehyde led to formation of thienylpyridine product 4, which subsequently reacted with ethyl chloroacetate or chloroacetaldehyde to furnish the thienopyridine derivatives (6,7). Moreover, the alkylation of compound 3 with various bromoalkyl ketones followed by Thorpe-Zeigler cyclization furnished the …

Introduction: Rodents, thriving in human-altered environments, pose significant
public health risks due to their role as reservoirs for numerous zoonotic parasites.
Among these, Cryptosporidium spp. are recognized globally as leading causes
of waterborne and foodborne diarrheal illnesses in humans. The specific role of
fat sand rats (Psammomys obesus) in the transmission of Cryptosporidium spp.
in Egypt and the genotypic characteristics of the circulating species in these
animals remain poorly understood.
Methods: In this study, a total of 150 individual fat sand rat stool samples were
collected from the saline marsh periurban areas of Abu-Rawash, Giza, Egypt. The
samples were initially screened for the presence of Cryptosporidium spp. using
light and scanning electron microscopy to characterize the parasite’s oocysts.
Furthermore, molecular identification and characterization of the parasite
were carried out on selected microscopy-positive samples (n = 30) using
conventional polymerase chain reaction (PCR) targeting the Cryptosporidium
oocyst wall protein (COWP) gene. A subset of these positive samples by PCR was
subjected to sequencing, with the resulting sequences deposited in GenBank™
and analyzed through phylogenetic methods.
Results: Conventional microscopy revealed that 46.7% (70/150; 95% CI:
38.7–54.6) of the analyzed stool samples contained structures consistent
with Cryptosporidium oocysts. Moreover, the molecular analysis confirmed
Cryptosporidium species in DNA from all 30 stool samples previously identified
as heavily infected through microscopy. Notably, the phylogenetic analysis
identified Cryptosporidium parvum (C. parvum) in the sequenced samples, likely
originating from the rats’ native habitats. These identified species have been
deposited in GenBank™ under the accession numbers OM817461 (C. parvum FSA-1), OM817462 (C. parvum FSA-2), and OM817463 (C. parvum FSA-3) and revealed closed genetic identity with those species reported from human and other animal species in the same geographic location.
Conclusion: Overall, this study represents the first morphological and genetic identification of C. parvum isolated from fecal samples of fat sand rats trapped from periurban areas in Egypt. These findings provide valuable insights into the potential zoonotic implications of rodents in disease transmission at the national level, offering crucial information for public health awareness campaigns and informing local authorities.