Reaction in Dry Media: Silica Gel Supported Ferric Chloride Catalyzed Synthesis of 1,8-Dioxo-octahydroxanthene Derivatives

Herein, we describe a green procedure for the one-pot preparation of 1,8-dioxo-octahydroxanthene derivatives by condensation of dimedone and substituted benzaldehydes in the presence of FeCl ₃ -SiO ₂ as an efficient and heterogeneous catalyst under microwave irradiation and thermal conditions. This method has the advantages of high yields, cleaner reactions, efficient and cost-effective method, simple methodology, short reaction times, easy workup, and greener conditions.     

Experimental and Quantum Chemical Studies of 5-Fluoroisatin-3-(N-Cyclohexylthiosemicarbazone) and Its Metal Complexes

Abstract

Zn(II) and Ni(II) complexes of 5-fluoroisatin-3-[-(N-cyclohexylthiosemicarbazone)] (H₂FIC) have been prepared and characterized structurally by means of elemental analyses, FTIR, electronic, and ¹H NMR spectra. The theoretical wavenumbers, IR intensities, and molecular parameters have been calculated by the ab-initio Hartree–Fock (HF) method with the LanL2DZ basis set. The theoretical wavenumbers show a good agreement with experimental data. The bond lengths, bond angles, the highest occupied molecular orbital energy (E_HOMO), the lowest unoccupied molecular orbital energy (E_LUMO), the energy gap between E_HOMO and E_LUMO (ΔE_HOMO-LUMO), dipole moment, and charges on the atoms of H₂FIC as monomer form were studied by the density functional theory/Becke-3-Lee-Yang-Parr (DFT/B3LYP) and ab-initio HF methods using 6-31G(d,p) basis set. The trimeric possible structure of H₂FIC was also investigated using HF method. The observed IR wavenumbers of the H₂FIC were analyzed in the light of the computed vibrational spectra of its monomer and trimer forms.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Studies on Quinazolines. Part I. Annelation to the Quinazoline Ring Utilizing Amino Acid Esters

The reaction of quinazoline-4(3H)-thiones 2a-d with amino acid ester hydrochlorides in boiling solvents, under the basic catalysis, afforded the corresponding substitution products (3-6)a-e in low yield. The reaction could be improved by carrying it without a solvent yielding imidazo[1,2-c]- and pyrimido[1,2-c]quinazolines (7-10)a-e . The antibacterial and antifungal activities of the prepared compounds were tested.     

Complexes of Tin(IV) Tetrachloride with 3-Formylpyridine Semicarbazone and Thiosemicarbazones

The reaction of tin(IV) tetrachloride with 3-formylpyridine semicarbazone and different 3-formylpyridine thiosemicarbazones produces [Sn(HL)CL 3 ][SnCl 5 ] where HL stands for the neutral ligand. The tin(IV) complexes were characterized using a variety of spectroscopic techniques. Coordination through the pyridine nitrogen occurs in all cases. Solvation studies in DMSO indicated that dissociation of the ligands and their complete replacement by solvent molecules occurs.     

One-Pot Synthesis of Thiazoles from Pyridazin-3-hydrazidic Acid Derivatives

Several new thiazole derivatives have been synthesized; the reactivity of these compounds toward amines, aldehydes, and hydroxyl amine are reported. New syntheses of pyrimidino[5,4:3,4]pyrazolo[4,3:5,6]pyridazine derivatives also have been achieved.     

Synthesis and Chemical Behavior of the N-Morpholino- O-Alkyl-3-Methyl-1,2-Butadienephosphonic Acid Esters

Abstract

The synthesis and the reactivity of the titled compounds towards electrophilic and nucleophilic reagents have been discussed.     

REDUCTIVE DEIMINATION OF SULFOXIMIDES AND SULFIMIDES WITH P-TOLUENESULFONYL NITRITE AND T-BUTYL THIONITRATE1

Abstract

Reduction of sulfimides and sulfoximides with p-toluenesulfonyl nitrite, a new nitrosating agent, gave nearly quantitatively the corresponding deimination products, sulfides and sulfoxides, respectively. In the reaction of dialkyl and aryl alkyl sulfoximides with t-butyl thionitrate, N-t-butylthiosulfoximides were obtained besides the usual deimination products, although diaryl sulfoximides were readily deiminated to the corresponding sulfoxides in good yields in the same treatment. t-Butyl thionitrate was also found to deiminate diphenyl sulfimide to give diphenyl sulfide in good yield. Sulfoximides reacted sluggishly with t-butyl thionitrite, however, eventually affording a small amount of sulfoxides.     

Impact of Geometric Parameters,Charge, and Lipophilicity on Bioactivity of Armed Quinoxaline,Benzothiaole, and Benzothiazine: Pom Analyses of Antibacterial and Antifungal Activity

Abstract

A series of four different armed heterocyclic candidates; 1-(2-methyl-2,3-dihydro-1,3-benzothiazol-2-yl)acetone (2), 1-(3-methyl-4H-1,4-benzothiazin-2-yl)ethanone (3), 2-[(2-aminophenyl)dithio]aniline (4), and 3-hydroxy-3-methyl-4-(3-methyl-2-quinoxalinyl)-2-butanone (5) have been prepared and their microbial activities were evaluated. A correlation of the structure and activities relationships of these compounds with respect to molecular modeling, Lipinski Rule of Five, drug likeness, toxicity profiles, and other physico-chemical properties of drugs are described and verified experimentally.