99463-11-3Relevant academic research and scientific papers
SUBSTITUTED PYRIDINE CARBOXYLIC ACIDS, THEIR PREPARATION METHOD AND COMPOSITIONS THEREOF
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Page/Page column 4, (2020/06/05)
The present invention relates to novel substituted pyridine carboxylic acid derivatives and their preparation methods. This invention is also directed to pharmaceutical compositions containing such compounds and combinations thereof with at least one ther
Sequence-Controlled Polymers Through Entropy-Driven Ring-Opening Metathesis Polymerization: Theory, Molecular Weight Control, and Monomer Design
Nowalk, Jamie A.,Fang, Cheng,Short, Amy L.,Weiss, Ryan M.,Swisher, Jordan H.,Liu, Peng,Meyer, Tara Y.
supporting information, p. 5741 - 5752 (2019/04/26)
The bulk properties of a copolymer are directly affected by monomer sequence, yet efficient, scalable, and controllable syntheses of sequenced copolymers remain a defining challenge in polymer science. We have previously demonstrated, using polymers prepared by a step-growth synthesis, that hydrolytic degradation of poly(lactic-co-glycolic acid)s is dramatically affected by sequence. While much was learned, the step-growth mechanism gave no molecular weight control, unpredictable yields, and meager scalability. Herein, we describe the synthesis of closely related sequenced polyesters prepared by entropy-driven ring-opening metathesis polymerization (ED-ROMP) of strainless macromonomers with imbedded monomer sequences of lactic, glycolic, 6-hydroxy hexanoic, and syringic acids. The incorporation of ethylene glycol and metathesis linkers facilitated synthesis and provided the olefin functionality needed for ED-ROMP. Ring-closing to prepare the cyclic macromonomers was demonstrated using both ring-closing metathesis and macrolactonization reactions. Polymerization produced macromolecules with controlled molecular weights on a multigram scale. To further enhance molecular weight control, the macromonomers were prepared with cis-olefins in the metathesis-active segment. Under these selectivity-enhanced (SEED-ROMP) conditions, first-order kinetics and narrow dispersities were observed and the effect of catalyst initiation rate on the polymerization was investigated. Enhanced living character was further demonstrated through the preparation of block copolymers. Computational analysis suggested that the enhanced polymerization kinetics were due to the cis-macrocyclic olefin being less flexible and having a larger population of metathesis-reactive conformers. Although used for polyesters in this investigation, SEED-ROMP represents a general method for incorporation of sequenced segments into molecular weight-controlled polymers.
Synthesis of Some Furfural and Syringic Acid Derivatives
Jogia, Madhu K.,Vakamoce, Veikila,Weavers, Rex T.
, p. 1009 - 1016 (2007/10/02)
The formation of several derivatives of furfural and syringic acid, including some incorporating both components, is described.Assignments of the 1H and 13C n.m.r. spectra are also included.
