Pretreatment of lignocellulosic materials is a prerequisite to facilitate the disruption of the natural recalcitrance of their carbohydrate-lignin shield and to allow enzymes to easily access the crystalline cellulose surfaces. Recently, pretreatment of ionic liquids (ILs) has been widely studied as a promising pretreatment technique; however, it is too expensive to be commercialized. In this study, an efficient acid-catalyzed aqueous IL pretreatment process was developed to optimize the total sugar conversion of pretreated biomass and to reduce IL usage. The experimental results demonstrated that the total sugar conversion was raised to 92.7 % with the synergistic effects of IL (1,3-dimethylimidazolium dimethylphosphate, [MMIM]DMP) and dilute hydrochloric acid (HCl) under pretreatment conditions of 110 °C for 2 h, compared to the conversion of only 27.3 % obtained with untreated corn stover. Moreover, the addition of the inorganic acids, especially HCl, to the IL pretreatment was found to not only significantly destroy the crystalline structure of cellulose in corn stover, promoting the conversion of cellulose and hemicellulose to monomeric sugars, but also provide an opportunity to reduce the usage of expensive IL solvents.

We report the discovery of two new forms (II and III) of a potential non-steroidal anti-inflammatory and thyroid drug, 2-((2,6-dimethylphenyl)amino)benzoic acid (HDMPA) through solution growth and thermal treatment of crystals. Form II has been discovered through crystal growth in a variety of solvents, and characterized by single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), FT-IR, and Raman spectroscopy. Form II converts into form III upon thermal treatment, as indicated by the phase behavior study of form II with differential scanning calorimetry (DSC). Form III has been characterized by IR, Raman and PXRD. Conformational flexibility of the molecule seems to lead to the polymorphism of the system. A conformational scan shows the conformational minima correspond to the conformers in the polymorphs. Lattice energy calculations show energies of À48.14 and À50.31 kcal mol À1 for forms I and II, providing information on the relative stability for each form. Hirshfeld analysis revealed that

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An efficient approach for the synthesis of functionalized 4-substituted-2-amino-3-cyano-4H-chromenes moderate to high yields (up to 98%) has been achieved via a tandem K2CO3 catalyzed conjugate addition-cyclization reaction of malononitrile and a range of Knoevenagel adducts previously formed from oxindole, pyrazolone, nitromethane, N,N-dimethylbarbituric acid or indanedione. This methodology differs from the previous classical methods in its simplicity and ready availability of the catalyst.

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