Structural Identification between Phthalazine-1,4-Diones and N-Aminophthalimides via Vilsmeier Reaction: Nitrogen Cyclization and Tautomerization Study

N-aminophthalimides and phthalazine 1,4-diones were synthesized from isobenzofuran-1,3-dione, isoindoline-1,3-dione, furo [3,4-b] pyrazine-5,7-dione, or 1H-pyrrolo [3,4-c] pyridine-1,3-dione with monohydrate hydrazine to carry out the 5-exo or 6-endo nitrogen cyclization under the different reaction conditions. Based on the control experimental results, 6-endo thermodynamic hydrohydrazination and kinetical 5-exo cyclization reactions were individually selective formation. Subsequently, Vilsmeier amidination derivatization was successfully developed to probe the structural divergence between N-aminophthalimide 2 and phthalazine 1,4-dione 3. On the other hand, the best tautomerization of N-aminophthalimide to diazinone was also determined under acetic acid mediated solution.

Synthesis, molecular and crystalline structure of 8-formylharmine

For the first time, synthesis of 8-formylharmine by the Vilsmeier reaction was carried out. 8-Formylharmine was obtained by treating alkaloid harmine with dichloromethoxymethane in the presence of SnCl4.The yield of the target product was 64 %. The structure of the obtained compound was established on the basis of 1H and 13C NMR spectroscopy as well as mass-spectrometry data. The crystalline structure of 8-formylharmine was determined by X-ray diffraction. It has been shown that the replacement of the hydrogen atom in the harmine molecule with a formyl group occurs at the C8 atom. It was revealed that the methoxy group at the C7 atom changes its orientation to the opposite one as compared to the orientation in the harmine molecule and its salts due to the mutual Van der Waals repulsion of the methoxy and formyl groups. A weak intramolecular hydrogen bond was found in the crystal between the O2 atom of the formyl group and the hydrogen atom of the secondary amino group. It was shown that molecules in the crystal form an intermolecular hydrogen bond between the same atoms (О2 and НN9A), as a result of which dimers are formed.

A Leopard Cannot Change Its Spots: Unexpected Products from the Vilsmeier Reaction on 5,10,15-Tritolylcorrole

The reaction of 5,10,15-tritolylcorrole with 3-dimethylaminoacrolein (3-DMA) and POCl3 gives a further example of the rebel reactivity of this contracted macrocycle. While no evidence was obtained for the formation of the expected β-acrolein corrole, the inner core substituted N21,N22-3-formylpropylcorrole and the 10-acrolein isocorrole were the reaction products. By increasing the temperature or the amount of the Vilsmeier reagent, the 10-isocorrole became the unique reaction product. The formation of the isocorrole by electrophilic attack of the Vilsmeier reagent to the 10-position of the corrole is unprecedented in the porphyrinoids field and it could pave the way for a novel route to the preparation of stable isocorroles.

Contribution of Resveratrol in the Development of Novel Urease Inhibitors: Synthesis, Biological Evaluation and Molecular Docking Studies

Aims and Objective: A new library of resveratrol derivatives was designed and synthesized in excellent yield via two-step reaction utilizing Vilsmeier reaction as the first step and subsequent addition of substituted aromatic amine in the second step. Methods: Synthesized compounds were investigated for their antioxidant as well as for in vitro inhibition activity against jack bean urease enzyme. Compounds R3b and R4 with IC50 value 18.85±0.15 and 21.60±0.19µM against urease enzyme and 6.01±0.07 and 7.52±0.14µM in vitro- DPPH free radical scavenging activity have emerged as most active molecules from the selected library. Molecular simulation studies were also carried out for determining the interaction detail of newly synthesized compounds within a protein pocket. Results and Conclusion: Newly synthesized compounds were found to possess better docking score (-5.941 to -6.894) and binding energy (-46.854 to -56.455) as compared to the parent resveratrol (-5.45 and -20.155) which revealed that the newly synthesized compounds bind in a better way as compared to the parent molecule

SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL EVALUATION OF NOVEL QUINOLINE BASED 2-AZETIDINONES AND 4-THIAZOLIDINONES

The present work describes the synthesis of a series of quinoline based 4-thiazolidinone and 2-azetidinone derivatives from Schiff bases obtained from the condensation of 2-chloro-3-formylquinoline and 3-4-aminoacetophenones. Quinoline based 4-thiazolidinone and 2-azetidinone derivatives have been prepared by the reaction of various substituted Schiff base with thioglycholic acid and chloroacetyl chloride, respectively. The intermediate Schiff bases were synthesized by the condensation of different quinoline aldehydes with amino acetophenones. The starting compound i.e aldehyde was synthesized through Vilsmeier reaction from respective acetanilides. The synthesized compounds were characterized by their physical and spectral data. The synthesized compounds were screened for their antibacterial and antifungal activities by using cup plate method against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, 25, 50, 100 μg/mL concentration using ciprofloxacin as reference standard drug and Aspergillus niger, Candida albicans as same concentration using clotrimazole as reference drug, respectively. The spectral data of synthesized compounds of (3a-f), (4a-e) and (5a-f) were characterized by ES Mass, 1H-NMR, IR spectrophotometric methods. The antimicrobial results revealed that the quinoline based Schiff bases, azitidinone and thiazolodinones analogues showed good activity towards Gram (+) bacteria as compared to ciprofloxacin. These compounds showed decent activity against Gram (-) bacteria.

Moving corrole towards a red-record: synthesis of β-acrolein Ga and Cu corroles using the Vilsmeier reaction

Pioneering the red region of emission! β-acrolein substituted Ga corroles show the longest fluorescence emission reported for monomeric corroles.

Microwave assisted synthesis of substituted 4-chloro-8-methyl-2-(1,3-diphenyl-1H-pyrazol-4-yl)-1,5-dioxa-2H-phenanthren-6-ones and their antimicrobial activity

Due to the potential antimicrobial activity of pyranochromenones and pyrazolines moieties, hybrid compounds containing both, substituted 4-Chloro-8-methyl-2-(1,3-diphenyl- -1H-pyrazol-4-yl)-1,5-dioxa-2H-phenanthren-6-ones (4a-g), have been synthesized from substituted (E)-1-(7-Hydroxy-4-methyl-8-coumarinyl)-3-(1,3-diphenyl -1H-pyrazol-4-yl)-2-propen-1-ones (3a-g) in good yield using the Vilsmeier reaction, by microwave-assisted method. The structures of all the compounds have been established on the basis of analytical and spectral data. All the synthesized compounds were tested in vitro for their antibacterial and antifungal activities. Some of the compounds have shown very good activity compared to standard drugs against all pathogenic bacteria and fungi.