1,3,5-Tri(1H-benzo[d]imidazol-2-yl)benzene derivatives, as a new kind of fluorescent chemosensor for the detection of nitroaromatic explosives, are designed and synthesized by simple N-hydrocarbylation. Among 16 obtained compounds, compound 4g has the best capability for detection of picric acid (PA), having good selectivity and high sensitivity. The detection of PA with 4g solution-coated paper strips at the picogram level is developed. A simple, portable, and low-cost method is provided for detecting PA in solution and contact mode.

The multifunctional fluorescent brightening agents (FBAs) simultaneously possessing chiral 2(5H)-furanone and bis-1,2,3-triazole moieties are synthesized as designed via the Click reaction of N-[(5S)-5-menthoxy-2(5H)-furanonyl] amino acid propargyl esters with 4,4′-diazidostilbene-2,2′-disulfonate sodium salt tetrahydrate in high yields (over 90%). Their structures are systematically characterized. In addition, the testing results of their properties from fluorescence spectroscopy, photoisomerization, and ultraviolet (UV) protection factor (UPF) test show that the novel FBAs have excellent fastness to acid and light, as well as UV resistance. Especially, when a larger alkyl group in the side chain of amino acid moiety is introduced into the structure of the FBA, the designed compound has a better fluorescent brightening effect as anticipated. Moreover, in the experiments of its sorption on paper fibers, the scanning electron microscopy (SEM) images with it show a rough surface, while others without it show a relatively smooth surface.

An efficient method for the synthesis of aminomethyl benzimidazoles is developed by using a one-pot batch reaction between amino acids and o-phenylenediamines. This reaction proceeds smoothly in an unmodified household microwave oven, even though scale-up is to 10 g. A desirable method for the quick synthesis of benzimidazoles, which are used as a kind of important intermediates in drug synthesis, is provided by the scale-up utilization of amino acid resource.

By using low cost and readily available amino acids as the synthetic blocks, a series of 2-aminomethyl-benzimidazole are synthesized with solvent-free melting method. While the condensation of aspartic acid (or asparagine) with o-diaminobenzene gives the fluorescent bisbenzimidazole product without amino group via the further deamination reaction in the melting reaction system. The condensation reactions between most amino acids and o-diaminobenzenes exhibits higher yields of 58 to 86 % (mostly over 66 %), shorter reaction time (5 h) than that previously reported and better tolerance for different functional groups in amino acids. The structures of twenty benzimidazoles with multifunctional groups, including thirteen new compounds, are systematically characterized with FTIR, 1 H NMR, 13 C NMR, MS and elemental analysis. These investigations are beneficial to the further researches on their applications in biochemistry, coordination chemistry and organic synthesis intermediates.

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2015): Synthesis and characterization of a novel drug-loaded polymer, poly(lactic acid-co-aminomethyl benzimidazole), Designed Monomers and Polymers, Using aminomethyl benzimidazole (AMB) as a model of benzimidazole-type drugs, a potential biodegradable drug-loaded polymer poly(lactic acid-co-aminomethyl benzimidazole) (PLAAMB) is synthesized as designed via direct melt polycondensation starting from D,L-lactic acid (LA). When the molar feed ratio LA/AMB is 40/1, the optimal synthetic conditions, including catalyst type and dosage, polycondensation temperature, and copolymerization time are discussed. After the prepolymerization at 140°C for 8 h, using 0.4 wt% stannous oxide (SnO) as the catalyst, the melt copolymerization at 160°C for 6 h gives the copolymer with the biggest weight-average molecular weight (M w ) 5300 Da. The structure and properties of the copolymer are systematically characterized with Fourier transform infrared, 1 H NMR, gel permeation chromatography, differential scanning calorimetry, and X-ray diffraction. And the investigations on the influences of different molar feed ratios on the properties of PLAAMB show that, the copolymer PLAAMB with the biggest M w of 9400 Da can be obtained. After the drug model AMB as a monomer is introduced into polylactic acid during the condensation, the T g of the obtained PLAAMB is lower than the T g of homopolymer poly(D,L-lactic acid) (PDLLA). The M w and crystallinity of PLAAMBs can meet the requirement of drug-loaded polymers in the drug delivery.