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A practical and scalable protocol for electrochemical arylation of quinoxalin(on)es with arylhydrazine hydrochlorides under mild conditions has been developed. This method exhibits high efficiency, easy scalability, and broad functional group tolerance. Various quinoxalin(on)es and arylhydrazines underwent this transformation smoothly in an undivided cell, providing the corresponding aryl-substituted quinoxalin(on)es in moderate to good yields. A radical mechanism is involved in this arylation reaction.

Visible light-driven self-catalyzed regulable alkylation of 2H-benzothiazoles with diverse aliphatic C–H donors via the combination of HAT and self-photoredox catalysis.

The ODS efficiency is in the order thiophene > dibenzothiophene > benzothiophene and may be attributed to the combined effect of HPMo and shape selectivity over Nano-TS-1.

A K2S2O8-catalyzed versatile C(sp2)–C(sp3) bond formation with N-heteroaromatics and γ-lactams/amides was developed. Quinoxalin-2(1H)-one, quinoline, isoquinoline, phthalazine, and benzothiazole reacted with γ-lactams/amides to give the corresponding C(sp2)–H amidoalkylation products in moderate to good yields with high regioselectivity. This visible-light-induced photocatalyst-free reaction was conducted in H2O at ambient temperature, which comply with the principles of “green chemistry”. The new K2S2O8 catalytic mechanism was investigated with control experiments.

An excellent catalyst for hydrodesulfurization, aromatization and olefin hydrogenation of FCC gasoline, is designed in this paper.

In this study, agomelatine Form I was selectively recrystallized from molten state induced by ethyl cellulose (EC). It was found EC could effectively inhibit the transformation process of Form I to Form II. The effect of EC on the recrystallization of agomelatine from molten state was studied in detail. Simultaneous X-ray powder diffraction (PXRD), differential scanning calorimetry (DSC), and polarized light microscopy (PLM) were used to investigate its thermodynamic performance. In addition, the stability and solubility of the Form I induced by EC were carefully explored indicating it gained more stability compared with other forms produced without EC.

The aim of this study is to improve in vitro and in vivo properties of an antihypertensive poorly soluble drug Telmisartan (TEL) by co-amorphization with a pharmacologically relevant drug Hydrochlorothiazide (HCT), and to improve the stability of single amorphous drugs. Herein, TEL-HCT co-amorphous systems (CAMs) (1:1, 2:3, 1:2, 1:3) were prepared by solvent evaporation. The apparent solubility and the dissolution of TEL in the TEL-HCT CAM (1:3) were increased by 79 times and 10 times compared to crystalline TEL, which showed the optimal properties. Cmax and AUC0-48h value of TEL-HCT CAM (1:3) were 10-fold and 3-fold as the crystalline state. Moreover, TEL-HCT CAM (1:3) remained stable in 60 °C, 0 % RH (30 days), 40 °C, 75 % RH (90 days) and 25 °C, 0 % RH (180 days). Positive ΔTgs were observed in all CAMs, suggesting the existence of potential intermolecular force. Fourier Transform-Infrared and Raman spectra were used to further prove the drug-drug interaction and predict potential mechanisms. Therefore, in the strategy of combined medication, CAM provides a promising way to transfer drugs with poor properties into systems with enhanced dissolution, greater bioavailability, and stabilized amorphous state, which has been proven in this study.

Ibrutinib(IBR) is an irreversible Bruton's tyrosine kinase inhibitor and has been classified as the Biopharmaceutical Classification System (BCS) class Ⅱ drug. The objective of the current study was to improve the physicochemical properties of IBR by co-crystallization. Based on ΔpKa analysis and structure analysis, we reported seven IBR pharmaceutical cocrystals with different structure types of co-formers such as hydroxy-2-naphthoic acids, mono-hydroxybenzoic acids, and aliphatic acids via the slurry method and ultrasonic method. The seven prepared cocrystals were characterized by powder X-ray diffraction(PXRD), differential scanning calorimetry(DSC), thermogravimetric analysis(TGA) and Fourier transform infrared spectroscopy(FT-IR). The solubility and accumulative dissolution of IBR cocrystals were explored. It was found that the solubility and dissolution were optimally increased up to 6.64 times and 1.85 times than that of IBR Form A, respectively. Moreover, all the IBR cocrystals maintained a stable cocrystal state after 90-d under 40 °C/75% RH condition and after 30-d under 60 °C/0% RH condition. According to the results analysis, there may be hydrogen bond(H-bond) and π-π stacking interactions in the IBR cocrystal system. The current study demonstrated that the co-crystallization of IBR with specific co-formers proposed a prospective technology and optional strategy to modify the physicochemical nature of IBR.

At present, coamorphous systems have attracted increasing interest in the pharmaceutical field owing to their enhanced stabilities, increased solubilities, and improved bioavailabilities compared with those of their pure amorphous and crystalline counterparts. In this study, a novel coamorphous solid form of ibrutinib (IBT) and saccharin (SAC) (1:1 molar ratio) was prepared through rotary vacuum evaporation and then characterized. Differential scanning calorimetry and X-ray powder diffraction indicated the formation of the coamorphous IBT-SAC after rotary vacuum evaporation. Compared with amorphous IBT, coamorphous IBT-SAC exhibited enhanced stability owing to the intermolecular interaction between IBT and SAC. Moreover, the solubility and dissolution of the coamorphous IBT-SAC were increased up to 4.0-7.7 times and 4.3 times, respectively, compared with those of its crystalline Form A. In addition to the superior behaviors of coamorphous IBT-SAC in vitro, the in vivo bioavailability study revealed notable increases in the Cmax and area under the curve0-t of the coamorphous form compared with those of its crystalline Form A. The current study demonstrates that the coamorphization of IBT and SAC presents a promising technology to overcome the limitations of solubility and stability that arise from IBT and can therefore contribute to a major improvement in the bioavailability of IBT.

To reveal the effect of the proportions and various properties of cellulose polymers towards the stability of amorphous celecoxib (CEL), the crystallization behavior of CEL polymorphs (Form I, Form II, and Form IV) has been thoroughly investigated. The results show that the addition of cellulose polymers can induce the nucleation of Form II and Form IV instead of Form I. With an increase in the proportion of polymer addition, there was a decrease in the birefringence phenomenon of Form I, while Form II and Form IV were observed to change in the opposite direction. The crystal growth of the three polymorphs depended on the proportion of HPMC and the temperature of environment instead of the molecular weight of polymers. The crystal growth analysis suggests that the energy barrier for nucleation may be one of the key factors. The cellulose polymers with large-sized substituents exhibited a stronger inhibitory effect during the crystallization of CEL polymorphs, where the amorphous CEL remained more stable. This phenomenon can be explained by FT-IR spectroscopy and ΔTg analysis, suggesting that there may be a steric repulsion from the large-sized substituents of cellulose polymers, which affects the crystallization process of CEL polymorphs.

Langasite-family single crystals Ca3NbGa3−xAlxSi2O14 (CNGAS) (x = 0.1–0.8) were grown by a Czochralski technique along the x-axis. With increasing amount of Al substituent, the lattice constants decreased and the electric resistivity in a high temperature range was improved. The CNGAS (x = 0.8) specimen had an electric resistivity of 1010 Ω cm at 350 °C. From the dependence of the resistivity on temperature, an activation energy of about 1.19 eV was obtained. Thermal treatment in oxygen atmosphere was also considered effective for the improvement in electric resistivity. However, the dielectric features associated with loss tangent jump at about 400 °C were not improved by the Al substituent and thermal treatment. Spectroscopic ellipsometry was applied to determine the pseudodielectric function e = e1 + ie2 spectrum of the Ca3NbGa3Si2O14 crystal from 2 to 6 eV at 27 to 450 °C. No crystal structure change was observed from room temperature to 450 °C. The mechanism of the loss tangent change above 400 °C needs further investigation.