25934-35-4Relevant academic research and scientific papers
Triphenylene-based side chain liquid crystalline block copolymers containing a PEG block: Controlled synthesis, microphase structures evolution and their interplay with discotic mesogenic orders
Wu, Bin,Mu, Bin,Wang, Sai,Duan, Junfei,Fang, Jianglin,Cheng, Rongshi,Chen, Dongzhong
, p. 2916 - 2929 (2013)
Triphenylene (TP) derivatives are typical and probably the most widely studied discotic liquid crystalline (DLC) materials. Through polymer analogous reactions to attach TP mesogens to the well-synthesized poly(ethylene glycol)-b-poly(2-hydroxyethyl acrylate) (PEG-PHEA) by ATRP, a series of well-defined side chain DLC diblock copolymers PEG-poly(TPm) (m = 6 or 10) with DLC block weight fraction (fw,DLC) ranging from 37% to 90% have been successfully prepared with narrow molecular weight distribution (PDI ≤ 1.11). An intriguing microphase-separated superstructure evolution and the correlation between overall morphologies and discotic mesogenic orders as a function of fw,DLC and temperature have been demonstrated by combination of DSC, POM, and variable temperature SAXS/WAXS. Those copolymers with lower DLC contents (fw,DLC = 37% and 43%) and at lower temperatures formed lamellar structures of variant periods and underwent order-order transitions upon PEG region crystallization at 45 C and different discotic mesophases of ND or Ncol transition at about 25 C. For the copolymer with intermediate fw,DLC = 62%, a high temperature hexagonal packed cylinder (HPC) structure of amorphous PEG nanocylinders in the matrix of DLC was formed above 35 C, while upon cooling below 35 C it turned into a mixed lamellar structure with PEG region crystallization. The higher fw,DLC (67% ～ 80%) copolymers exhibited HPC structures with the DLC matrix showing Ncol or ND mesophases. For copolymers with the highest fw,DLC around 90%, an overall ND phase was developed in sharp contrast to the ordered columnar phase formed by their corresponding DLC homopolymers, which was quite inspiring and might suggest another pathway of attaining this important nematic discotic phase through introducing a suitable copolymerized block. The better understanding of the interrelation of microstructures and discotic mesogenic orders constitutes the key basis for utilizing such type of organic semiconductor materials and could help to guide the design of complex DLC polymer materials with hierarchical structures for variant applications.
Side-chain shuffling: Regioselective synthesis of mixed tail discotic mesogens
Voisin, Emilie,Williams, Vance E.
, p. 11262 - 11265 (2016/02/09)
A procedure for the regioselective synthesis of discotic mesogens bearing multiple side chains of different lengths is reported. A series of isomeric dibenzoquinoxaline mesogens obtained by this route showed phase behaviour that was highly sensitive to chain location.
Design and synthesis of a novel and potent series of inhibitors of cytosolic phospholipase A2 based on a 1,3-disubstituted propan-2-one skeleton
Connolly, Stephen,Bennion, Colin,Botterell, Sarah,Croshaw, Pamela J.,Hallam, Catherine,Hardy, Kim,Hartopp, Paul,Jackson, Clive G.,King, Sarah J.,Lawrence, Louise,Mete, Antonio,Murray, David,Robinson, David H.,Smith, Gillian M.,Stein, Linda,Walters, Iain,Wells, Edward,Withnall, W. John
, p. 1348 - 1362 (2007/10/03)
Using knowledge of the substrate specificity of cPLA2 (phospholipases A2), a novel series of inhibitors of this enzyme were designed based upon a three point model of inhibitor binding to the enzyme active site comprising a lipophilic anchor, an electrophilic serine "trap", and an acidic binding moiety. The resulting 1,3-diheteroatom-substituted propan-2-ones were evaluated as inhibitors of cPLA2 in both aggregated bilayer and soluble substrate assays. Systematic variation of the lipophilic, electrophilic, and acidic groups revealed a well-defined structure-activity relationship against the enzyme. Optimization of each group led to compound 22 (AR-C70484XX), which contains a decyloxy lipophilic side chain, a 1,3-diaryloxypropan-2-one moiety as a unique serine trap, and a benzoic acid as the acidic binding group. AR-C70484XX was found to be among the most potent in vitro inhibitors of cPLA2 described to date being more than 20-fold more active against the isolated enzyme (IC50 = 0.03 μM) than the standard cPLA2 inhibitor, arachidonyl trifluoromethyl ketone (AACOCF3), and also greater than 10-fold more active than AACOCF3 against the cellular production of arachidonic acid by HL60 cells (IC50 = 2.8 μM).
Process for the preparation of 3,4-dialkoxyanilines
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, (2008/06/13)
A new process for the production of 3,4-dialkoxyanilines in which the two alkyl groups are different from each other is disclosed. The process comprises the stepwise introduction of the alkyl groups in different stages of the process by converting pyrocatechol into its monoalkyl ether, coupling said monoalkyl ether with a phenyldiazonium salt, alkylating the 3-alkoxy-4-hydroxy-azobenzene obtained to form 3,4-dialkoxyazobenzene and reductively cleaving the latter to the corresponding 3,4-dialkoxyaniline. The 3,4-dialkoxyanilines obtainable by the new process are valuable intermediates for the preparation of 4-hydroxy-6,7-dialkoxy-3-quinoline carboxylic acid esters which are excellent coccidiostats.
