This work aims the synthesis of amidino pyrazolines by the cyclocondensation reaction between 3-(hetero)aryl-1-(2-hydroxyphenyl)enones and aminoguanidine hydrochloride under sonochemical conditions. Thirteen new compounds were synthesized in 15-83% of yield after sonication for 30 min without purification by chromatography. Furthermore, antimicrobial activities of the synthesized compounds were investigated by in vitro minimum inhibitory concentration (MIC) in a panel of four bacterial strains and four Candida yeasts. As result, the 5-(4-bromophenyl)-3-(2-hydroxyphenyl)-4,5-dihydro-1H-pyrazole-1-carboximidamide hydrochloride was identified as the most active against gram-positive S. aureus and E. faecalis with MIC of 7.8 µg mL−1, similar to the value showed by chloramphenicol, which was used as standard.

An electrophilic iodocyclization reaction involving alkynylated 2-iodoanisoles and molecular iodine in the presence of sodium bicarbonate was developed and diiodo-functionalized benzo[b]furans were obtained in yields from 45 to 99%.

This article reports the synthesis and characterization of pure and N-, B-, and Ag-doped TiO2 and the ability of these oxides to photodegrade methylene blue (MB) under sunlight or UV-ABC radiation. The compounds were synthesized using the sol-gel method and characterized by scanning electron microscopy, X-ray diffraction, diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy. Photocatalytic efficiency was significantly increased by N-doping, resulting in 98% MB decomposition under UV-ABC irradiation for 180 min. Ag- and B-doped TiO2 lowered MB degradation rates to 52 and 73%, respectively, compared with pure TiO2. The same behavior was observed with exposure to UV-Vis, with 88, 65, 60, and 42% MB removal with N-doped, pure, B-doped, and Ag-doped TiO2, respectively. Under visible light alone, N-doped TiO2 exhibited higher photocatalytic efficiency than commercial P25-type TiO2. Photocatalysis with N-doped TiO2 proved to be a promising alternative for MB degradation, given the potential of employing solar energy, thus minimizing operating costs.

3-(Thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-carboximidamides were efficiently prepared through a cyclocondensation of thiophenylchalcones with aminoguanidine hydrochloride under ultrasonic conditions in the presence of KOH and ethanol as a green solvent in short reaction times (15-35 min) and good yields (62-95%). All compounds produced were evaluated against the human Jurkat and RS4;11 acute lymphoblastic leukemia cell lines of T- and B-cell origin, respectively, and the K562 myelogenous leukemia cell line. Six compounds presented half maximal inhibitory concentration (IC50) values around 15 µmol L-1 and five compounds presented IC50 values around 40 µmol L-1 for at least one of the three cell lines analyzed. One compound was not significantly cytotoxic, presenting IC50 value > 100 µmol L-1.

This article reports the characterization of mesoporous Nb2O5 synthesized by the sol-gel method for application in photocatalysis. The emerging contaminant methylviologen was employed for photocatalytic tests. Parameters inherent to the synthesis process, such as stirring rate, aging temperature, and calcination temperature, were employed for a range of values to improve the synthetic route. The powders obtained were characterized by thermogravimetric analysis, X-ray diffraction, scanning and transmission electron microscopy, specific surface area, infrared spectroscopy, energy-dispersive spectroscopy, and diffuse reflectance spectroscopy. In samples calcined at 450 °C, a mixture of amorphous and hexagonal phases was observed, with a predominance of the former, while in samples calcined at 650 °C the orthorhombic phase predominated. Samples calcined at 450 °C exhibited larger specific surface areas. Mesoporous structures were confirmed for samples T8035M450 and T8045mi450, which displayed higher photoactivity, with roughly 90% removal of methylviologen.

A series of twelve novel 2-(pyrazol-1-yl)pyrimidine derivatives was easily obtained under ultrasonic conditions by the cyclocondensation reaction of 1-carboxamidino-pyrazoles with 4-methoxyvinyl-trifluoromethyl ketones using ethanol as an environment-friendly solvent in the presence of potassium hydroxide. Comparison of the ultrasound-promoted reaction with classical methodology shows that the former is faster and gives better yield. The products were isolated in excellent purity grades without purification by chromatography or recrystalization.

A reação de acoplamento entre 2,6-diiodoanisóis e alcinos terminais usando Pd(PPh3)2Cl2 e CuI como catalisadores e diisopropilamina como base em tolueno a temperatura ambiente por 12 h produziu seletivamente 2-iodoanisóis aquinilados, em rendimentos de bons a excelentes (52-95%), os quais são blocos de construção úteis com potencial aplicação na síntese de benzo[b]furanos funcionalizados.

The coupling reaction between 2,6-diiodoanisoles and terminal alkynes using Pd(PPh3)2Cl2 and CuI as catalysts and diisopropylamine as base in toluene at room temperature for 12 h produced selectively alkynylated 2-iodoanisoles, in good to excellent yields (52-95%), which are useful building blocks with potential application in the synthesis of functionalized benzo[b]furans.