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The synthesis conditions of HZSM-5 zeolite, including crystallization temperature, crystallization time and raw material ratio, were investigated by L32 (48) orthogonal test to specifically optimize its performance in dimethyl ether (DME) aromatization for the first time. Based on the total yield of aromatic products, the synthesis conditions of HZSM-5 zeolite with the best DME aromatization properties were obtained by comprehensive analysis and validation experiments. The relationship between the aromatization performance, crystalline structure, pore structure, and acidity of HZSM-5 zeolite were analyzed. The results showed that the HZSM-5 zeolite accompanied by hierarchical structure, an appropriate Brønsted and Lewis acid content and uniform crystal morphology, was successfully synthesized under optimized conditions. Over this unmodified and un-doped catalyst, the conversion of DME approached to 99.3% and the total yield of aromatics reached was 53.5%. [ABSTRACT FROM AUTHOR]

In this article, we describe the use of diphenyl carbonate (DPC) as a carbonyl source instead of isocyanate to synthesize asymmetric substituted urea derivatives. In a study aiming to discover new lead compounds with agricultural activities, thiazole[5,4-b]pyridine ureas were prepared by this method and characterized by mass spectrometry, elemental analysis, and 1H NMR spectroscopy. The biological activities show that the title compounds have moderate activities on herbicide, fungicide, and plant growth regulation. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT[image omitted] [ABSTRACT FROM AUTHOR]