Synthesis, antifungal and anti-hiv activities of new heterocyclic compounds

Thiophene chalcones, pyrazolines and 1,5-benzodiazepines are important heterocyclic compounds which show broad spectrum of biological activities. Three series of heterocyclic chalcones and their N-acetylated pyrazoline derivatives have been synthesized in low to good yields. The first step in this study is the synthesis of 3-acetyl-2,5-dichlorothiophene and 2-acetyl-5-chlorothiophene as heterocyclic ketones using Friedel-Crafts acylation. All thiophene chalcones were synthesized in three separate reactions by Claisen-Schmidt reaction of substituted thiophene aldehydes with ketones. Several acetophenone derivatives (series 2 and 3) were produced by cyclization reaction using hydrazine hydrate to form new and known N-acetylated pyrazoline derivatives. A series of substituted 1,5-benzodiazepines were synthesized in moderate to good yields. 4-Methyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one was synthesized as starting material by reacting ortho phenylenediamine and crotonic acid in the presence of toluene. Cyclization of the starting material with appropriate acid chlorides, unsubstituted and five types of groups (fluoro, chloro, bromo, methyl and methoxy) attached at ortho, para and meta position of phenyl ring in the presence of triethylamine and anhydrous tetrahydrofuran have furnished substituted 1,5-benzodiazepines. The structures of the compounds were confirmed by infrared (IR), 1H NMR and 13C NMR (1D and 2D) nuclear magnetic resonance spectroscopies. Compounds of series 2 and 3 were tested for their antifungal activities against two types of pathogenic strains, namely Candida albicansa and Aspergillus niger with fluconazole as standard drug. The results for series 2 showed that the presence of bromo and methoxy substitution at para position on phenyl ring in chalcone and pyrazoline, respectively, resulted in significant enhancement in potency against both tested fungal strains with MIC value of ＞64 µg/mL. Compound carrying para fluoro on phenyl ring in pyrazoline derivatives exhibited the highest potency with MIC value of ＞32 µg/mL and 64 µg/mL against C. albicans and A.niger, respectively, among the series 3. The anti-HIV-1 RT assay of substituted 1,5-benzodiazepines (series 4) showed that the presence of chloro substitution at meta and ortho position inhibited the activity of HIV-1 RT with IC50 values 6.87 and 8.62 µM, respectively

Synthesis and characterization of heterocyclic chalcones containing halogenated thiophenes

Heterocyclic chalcones containing halogenated thiophenes were synthesized. The first step was to synthesize 3-acetyl-2,5-dichlorothiophene and 2-acetyl-5-chlorothiophene as heterocyclic ketones by using Friedel-Crafts acylation. The ketones were then used to synthesize thiophene chalcones through Claisen-Schmidt reaction with the respective heterocyclic aldehydes such as 5-bromothiophene-2-carbaldehyde, 3-methyl-2-thiophene carboxaldehyde and 2-thiophene carboxaldehyde with 3-acetyl-2,5-dichlorothiophene or 2-acetyl-5-chlorothiophene in presence of basic medium, sodium hydroxide to form the corresponding chalcones. Structures of the synthetic compounds were confirmed by IR, MS, 1H and 13C NMR spectral data

(E)-3-(3-methylthiophen-2-yl)-1-p-tolylprop-2-en-1- one. corrigendum

In the paper by Naveen et al. [IUCrData (2017), 2, x170234], there was an error in the name of one of the authors

Synthesis, spectroscopic, quantum computation, electronic, AIM, Wavefunction (ELF, LOL) and Molecular Docking investigation on (E)-1-(2,5-dichlorothiophen-3-yl)-3-(thiophen-2-yl)-2-propen-1-one

The compound (E)-1-(2,5-dichlorothiophen-3-yl)-3-(thiophen-2-yl)-2-propen-1-one (DClTP) was synthesized and analyzed using FT-IR, FT-Raman and 1H and13C NMR spectroscopic tools. The Gaussian computations were carried out by DFT method using B3LYP functional and 6–311G(d,p) as basis sets. The 13CNMR and 1H NMR were calculated by using the Gauge Independent Atomic Orbital (GIAO) method. AIM topology analysis was done on the molecule. NBO analysis was used to study the donor – acceptor interaction in the molecule. Chemical reactive site of the molecule was analyzed in MEP profile. The significance of Mulliken charge in the molecule and corresponding charge in Fukui function were also discussed. The different density of states was also computed by the same method. Various thermodynamic parameters were also discussed at various temperatures. Molecular docking was carried out using Autodock programming package for DClTP compound which exhibits the inhibitor human chorionic gonadotropin protein

Temperature dependence of the Raman spectrum of 1-(4-chlorophenyl)-3-(2-thienyl)prop-2-en-1-one

The heterocyclic chalcone containing thiophene ring 1-(4-chlorophenyl)-3-(2-thienyl)prop-2-en-1-one, C13H9ClOS was synthesized and investigated using experimental techniques such as nuclear magnetic resonance (1H and 13C NMR), Fourier transform infrared spectroscopy (FTIR) at room temperature, differential scanning calorimeter (DSC) from room temperature to 500 K and Raman scattering at the temperature range 10–413 K in order to study its structure and vibrational properties as well as stability and possible phase transition. Density functional theory (DFT) calculations were performed to determine the vibrational spectrum viewing to improve the knowledge of the material properties. A reasonable agreement was observed between theoretical and experimental Raman spectrum taken at 10 K since anharmonic effects of the molecular motion is reduced at low temperatures, leading to a more comprehensive assignment of the vibrational modes. Increasing the temperature up to 393 K, was observed the typical phonon anharmonicity behavior associated to changes in the Raman line intensities, line-widths and red-shift, in special in the external mode region, whereas the internal modes region remains almost unchanged due its strong chemical bonds. Furthermore, C13H9ClOS goes to melting phase transition in the temperature range 393–403 K and then sublimates in the temperature range 403–413 K. This is denounced by the disappearance of the external modes and the absence of internal modes in the Raman spectra, in accordance with DSC curve. The enthalpy (ΔH) obtained from the integration of the endothermic peak in DSC curve centered at 397 K is founded to be 121.5 J/g