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To find new antiviral agents, novel chalcone derivatives containing a purine moiety were designed and synthesized by combining bioactive substructures. The antiviral activities of the derivatives against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV) were evaluated. Results showed that most of the derivatives showed antiviral activities. Compounds 3n and 3p exhibited excellent curative, protective and inactivation activities against TMV, with the EC50 values of 452.4, 416.2, 241.2 and 438.7, 418.6, 261.7 µg•mL−1, respectively, which were better than those of ribavirin (585.8, 436.0 and 268.7 µg•mL−1). Compounds 3n and 3p showed remarkable curative and protective activities against CMV. Compound 3n showed a moderate affinity to TMV coat protein, with binding constant Ka and Kd values of 1.5 × 104 L•mol−1 and 79.8 µmol•L−1, respectively. These findings provided an important structural insight for further designs of highly active chalcone derivatives and a basis for further study on their mechanism of action.

Mannich reactions of imine with acetylacetone were effectively catalyzed by the modified chiral cinchona alkaloid-derived thiourea. The reactions led to chiral β-amino carbonyl compounds in high yields and good enantioselectivities. The study demonstrated for the first time that Mannich reactions of unmodified acetylacetone with heterocyclic imine derived from benzothiazole can be promoted by chiral bifunctional organocatalyst.

[BMIM]Cl catalyzed three component Mannich-type reaction of 4-(quinazolin-4-yloxy)benzenamine and aldehyde with dialkyl phosphite under microwave irradiation has been described. The salient features of the reaction leading to new α-aminophosphonates include shorter reaction time and good yields. The method is environmentally friendly and does not require toxic catalysts or solvents. To the best of our knowledge, this is the first report for [BMIM]Cl induced one-pot synthesis of α-aminophosphonate derivatives.

The present report describes a chiral HPLC method for the enantiomeric separation of α-aminophosphonate derivatives using two new coated and immobilized amylose-based chiral stationary phases (CSP, Chiralpak IA and Chiralpak AD-H). The chromatographic parameters such as retention factor (k), separation factor (α), and resolution (Rs) of the solutes were investigated on these two CSPs. Reasonably good baseline separation for these compounds was achieved using Chiralpak IA column. The influences of temperature, content of ethanol modifier and the structure of analyte were also studied. THF, EtOAc and CH2Cl2 were used as eluents on analytical and semi-preparative columns. Highly enriched enantiomers with purities of up to 96.4% –100% (ee) and yields of 90.2% –95.5% were obtained, respectively. The proposed methods were found to be suitable and accurate for rapid separation and semi-preparation of enantiomeric α-aminophosphonate derivatives available.

Ten new 2-(3,4,5-trimethoxyphenyl)-5-[(5-alkylthio-1,3,4-oxadiazol-2-yl)methylthio]-1,3,4-thiadiazole derivatives were synthesized from 2-mercapto-5-(3,4,5-trimethoxypheny1)-1,3,4-thiadiazole in four steps of thioetherification, hydrazidation, cyclization and thioetherification. The synthesis of the title compounds catalyzed by In(OTf)3 at 40 °C in aqueous media was easily achieved in high yields under environmentally benign conditions. Furthermore, In(OTf)3 can be recovered and reused without any notable loss of its catalytic activity.

Ten new 1-(5-(2-chlorophenyl)-3-(2,4-dichlorophenyl)-4,5-dihydropyrazol-1-yl) oxime ester derivatives were synthesized and characterized by elemental analysis, HRMS and 1H NMR data. All the compounds have been screened for their antibacterial potential in vitro against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The results show that 7c and 7f possess significant activity with the minimum inhibitory concentrations (MIC) value of 1.562 µg/mL against all the four bacteria. Compounds 7c, 7d and 7f show moderate inhibition against the DNA gyrase (IC50=1.6–2.5 µg/mL). On the basis of the biological result, the structure-activity relationship was discussed.

Chiral α-aminophosphonates were synthesized using (R) or (S)-1-phenylethylamine in the presence of BF3·Et2O under microwave irradiation in moderate to good yields. The new compounds were identified by 1H NMR, 19F NMR, IR and elemental analysis. Their antifungal activities were evaluated and some compounds were found to exhibit excellent antifungal activities. To the best of our knowledge, this is the first report on antifungal activity of chiral α-aminophosphonates containing fluorine moiety.

An environmentally benign and efficient process for the preparation of 3-(substituted methylthio)-4-phenyl-5- (3,4,5-trimethoxyphenyl)-4H-1,2,4-triazole was achieved by the reaction of 4-phenyl-5-(3,4,5-trimethoxyphenyl)- 4H-1,2,4-triazole-3-thiol with different halides in aqueous media mediated by indium trichloride in high yields.

A series of 2,3,4-trimethoxyacetophenoxime esters containing benzothiazole moiety were synthesized by the reaction of oxime with acyl chloride in alkaline medium. Their structures were established by elemental analysis, IR, and 1H NMR spectra. The bioassay tests showed that these title compounds exhibit moderate anticancer activity in vitro by MTT method and compounds 6c and 6d could inhibit ERK phosphorylation in NIH 3T3 cell induced by PDGF.