Synthesis of a new aromatic diacid containing pyridine ring and related polybenzimidazole

A new aromatic diacid monomer containing pyridine unit,4-phenyl-2,6-bis[4-（4-carboxyphenoxy） phenyl]pyridine 3,was successfully synthesized in three steps,starting from 4-hydroxyacetophenone.The corresponding pyridine-containing polybenzimidazole was prepared via polycondensation of 3 with tetraaminodiphenyl ether（TADE） in poly（phosphoric acid）（PPA）.The resulting polybenzimidazole exhibits excellent solubility,good thermal stabilities and high thermal resistance.

Study on direct-chain diacid modified phenolic resin for Al-alloy casting

Resin coated sand (RCS) with phenolic resin matrix can hardly be collapsed when it is used in Al-alloy casting. Adding collapsing agent and reducing the concentration of resin are solutions adopted by workers, but these methods tend to reduce the initial strength of RCS. Synthesis of modified phenolic resin with direct-chain diacid DAn (/JS=6, where n means carbon amount) was studied here. The effects of the addition of modifying agent on molecular weight, gel time and softening point were investigated. Optimal addition of DAn (10% phenol) was obtained by testing the initial and retained flexural strengths of the modified resin. FT-IR spectra showed that carbonyl shifts to higher wave number. With the use of TG, SEM and strength loss curves, the relation between initial and retained strengths was analysed. Tests on the heated deformation curve, before and after resin modification, show that PF-DA10 has the characteristic of higher initial and retained strengths together.

POLYMERIZATION OF N,N'-(PYROMELLITOYL)-BIS-L-LEUCINE DIACID CHLORIDE WITH HYDANTOIN DERIVATIVES BY MICROWAVE IRRADIATION

Facile and rapid polycondensation reactions of N,N'-(pyromellitoyl)-bis-L-leucine diacid chloride 1 with eight different derivatives of hydantoin compounds 2a-h were developed by using a domestic microwave oven in the presence of a small amount of polar organic medium such as o-cresol. The polycondensation reactions proceeded rapidly, compared with the conventional solution polycondensation, and was completed within 7-10 min, producing a series of novel optically active poly(amide-imide)s 3a-h with high yield and inherent viscosity of 0.35-0.65 dL/g. All of the above polymers were fully characterized by FT-IR, elemental analyses, inherent viscosity (η inh ), solubility test and specific rotation. Some structural characterization and physical properties of these optically active poly(amide-imide)s are reported.

Synthesis and Characterization of Poly(ether amide)s Containing Phthalazinone Moieties

Soluble aromatic polyamides containing phthalazinone moieties were prepared. Those polymers were obtained from the solution polymerization of a new diacid containing phthalazinone moieties with various diamines. The new monomer, 2-(4-carboxyphenyl)-4-(4- carboxyphenoxy ) phenyl-1 (2H) phthalazinone (Ⅳ) was synthesized in a two-step reaction sequence. 2- (4-Cyanophenyl)-4-(4-cyanophenoxy)phenyl-1 (2H)phthalazinone (Ⅲ) was prepared via the condensation reaction of 4-(4-hydroxyphenyl )-1 (2H) phthalazinone (I) with p-chlorobenzonitrile (Ⅱ). After (Ⅲ) was hydrolyzed, (Ⅳ) was acquired. The synthesized polyamides were characterized by means of viscosimetry, DSC, FT-IR, ~1H NMR and EA. The polyamides have a high glass transition temperature which can be as high as 316 C. The polyamides also have good solubilities in some organic solvents.

Theoretical studies on the structural change in the N-protonated tetraphenylporphyrin

The geometries of tetraphenylporphyrin which is a kind of important porphyrin derivatives, and its N-protonated diacid are calculated with AM1 MO method under symmetry restriction. The configurational changes and their effects on molecular aggregation are discussed by means of structure analysis, charge population analysis and frontier orbital analysis.

Discovery of Novel Long-Chain Alkenyl Diacid Derivatives as ACLY Inhibitors

ATP citrate lyase(ACLY)synthesizes cytosolic acetyl coenzyme A(acetyl-CoA),an essential biosynthetic precursor for lipid synthesis and the acetyl donor required for protein acetylation.The aberrant expression and activity of ACLY has been documented in multiple human cancers.ETC-1002 is an indirect ACLY inhibitor,and it has recently been approved by the FDA as an additional therapeutic option in high-risk hypercholesterolemia patients unable to meet goals with standard therapy.In this work,we identified a series of novel long-chain alkenyl diacids as potent direct ACLY inhibitors,and comprehensive structure-activity relationship analysis showed that compound 18f was the most potent ACLY inhibitor with an IC50 value of 1.5μmol/L.Subsequent ester formation of 18f gave a new series of compounds such as 25f that maintained ACLY inhibitory activity and improved antitumor cell proliferation effects.