Synthesis and Transformation of Methyl 2‐(6‐Hydroxy‐2‐phenylpyrimidin‐4‐yl)acetate: Simple Preparation of Pyrimidines with Heterocyclic Substituents

A simple and efficient synthesis of four new substituted pyrimidines, compounds 9a – d , from the title compound 3 is described. Conversion of 3 to methyl (E)‐3‐(dimethylamino)‐2‐(6‐methoxy‐2‐phenylpyrimidin‐4‐yl)prop‐2‐enoate ( 4 ), followed by condensation with various dinucleophiles according to the ‘enaminone methodology’, afforded the target compounds 9 in medium‐to‐good yields.     

Three Ternary Rare Earth(III) Complexes Based on 3‐[(4,6‐Dimethyl‐2‐pyrimidinyl)thio]‐propanoic Acid and 1,10‐Phenanthroline: Synthesis,Crystal Structure and Antioxidant Activity

Three ternary rare earth [Nd^III ( 1 ), Sm^III ( 2 ) and Y^III ( 3 )] complexes based on 3‐[(4,6‐dimethyl‐2‐pyrimidinyl)thio]‐propanoic acid (HL) and 1,10‐phenanthroline (Phen) were synthesized and characterized by IR and UV/Vis spectroscopy, TGA, and single‐crystal X‐ray diffraction. The crystal structures showed that complexes 1 – 3 contain dinuclear rare earth units bridged by four propionate groups and are of general formula [REL₃(Phen)]₂ · nH₂O (for 1 and 2 : n = 2; for 3 : n = 0). All rare earth ions are nine‐coordinate with distorted mono‐capped square antiprismatic coordination polyhedra. Complex 1 crystallizes in the monoclinic system, space group P2₁/c with a = 16.241(7) Å, b = 16.095(7) Å, c = 19.169(6) Å, β = 121.48(2)°. Complex 2 crystallizes in the monoclinic system, space group P2₁/c with a = 16.187(5) Å, b = 16.045(4) Å, c = 19.001(4) Å, β = 120.956(18)°. Complex 3 crystallizes in the triclinic system, space group P1 with a = 11.390(6) Å, b = 13.636(6) Å, c = 15.958(7) Å, α = 72.310(17)°, β = 77.548(15)°, γ = 78.288(16)°. The antioxidant activity test shows that all complexes own higher antioxidant activity than free ligands.     

Synthesis of π‐Conjugated Polymer Consisting of Pyrrole and Fluorene Units by Ru‐Catalyzed Site‐Selective Direct Arylation Polycondensation

Polycondensation of 1‐(2‐pyrimidinyl)pyrrole with 2,7‐dibromo‐9,9‐dioctylfluorene via Ru‐catalyzed direct arylation gives the corresponding conjugated polymer with a molecular weight of 19 800 in 86% yield. The introduction of directing group, 2‐pyrimidinyl substituent, into the pyrrole monomer induces ortho‐metalation and provides the site‐selective direct arylation polycondensation at the α‐position of pyrrole unit without the protection of β‐position. The removal of 2‐pyrimidinyl substituent on the pyrrole unit proceeds efficiently and results in the enhancement of coplanarity along the main chain of the polymer.

     

一类新型嘧啶苯氧(硫)醚的合成及生物活性

一类新型嘧啶苯氧(硫)醚的合成及生物活性;双乙烯酮; 氯硝基嘧啶; 苯氧（硫）醚; 嘧啶肼; 生物活性     

Preparation of polyethylene oxide with 4-amino-N-(2-pyrimidinyl) benzene sulfonamide and diethylenetriaminepentaacetic acid end groups and its enrichment in tumour tissues

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嘧啶脲类化合物的合成及其除草活性

嘧啶脲类化合物的合成及其除草活性李斌林柄栋刘长令魏晓丽（化工部沈阳化工研究院沈阳１１００２１）关键词嘧啶异氰酸酯嘧啶脲合成除草剂４０年代开发的取代脲除草剂如敌草隆等已得到了广泛应用［１］，但由于用药量较大，已逐渐被磺酰脲类除草剂取代。在这类磺酰脲除草...     

采用电位滴定法在DMSO/H2O混合溶剂体系中测定磺酰脲(胺)类除草剂的酸离解常数

采用电位滴定法在DMSO/H₂O(质量比80:20)混合体系中测定了磺酰脲和三唑并嘧啶磺酰胺类除草剂的酸离解常数,进而采用回归分析方法探讨了测得的pK_a值与化合物的前沿轨道能级以及取代基效应之间的相关性,结果较为满意,从而证明从该体系测得的pK_a值用于构效关系分析是完全可行的.     

Theoretical study on the hydrolysis mechanism of N,N-dimethyl-N'-(2-oxo-1, 2-dihydro-pyrimidinyl)formamidine: water-assisted mechanism and cluster-continuum model

The hydrolysis reaction of N,N-dimethyl-N'-(2-oxo-1, 2-dihydro-pyrimidinyl)formamidine (DMPFA), a model compound of the antivirus drug amidine-3TC (3TC = 2', 3'-dideoxy-3'-thiacytidine), is investigated by the hybrid density functional theory B3LYP/6-31+G (d,p) method. The hydrolysis reaction of the title compound is predicted to undergo via two pathways, each of which is a stepwise process. Path A is the addition of H2O to the C=N double bond in the amidine group to form a tetrahedral structure in its first step, and then the transfer of the H atom of hydroxyl leads to the corresponding products via four possible channels. Path B simultaneously involves the nucleophilic attack of H2O to the C atom of the C=N bond and the proton transfer to the N atom of amino group leading to the cleavage of the C-N single bond in the amidine group. The results indicate that path A is more favorable than path B in the gas phase. Moreover, to simulate the title reaction in aqueous solution, water-assisted mechanism and the cluster-continuum model, based on the SCRF/CPCM model, are taken into account in our work. The results indicate that it is rational for two water molecules served as a bridge to assist in the first step of path A and that cytosine rather than the cytosine-substituted formamide should be released from the tetrahedral intermediate via s six-membered cycle transition state (channel 2). Our calculations exhibit that the process toward the tetrahedral intermediate is the rate-determining step both in the gas phase and in aqueous solution.     

Prediction of anti-HIV activity and cytotoxicity of pyrimidinyl and triazinyl amines: A QSAR study

A QSAR study on a series of pyrimidinyl and triazinyl amines was performed to explore the physico-chemical parameters responsible for their anti-HIV activity and cytotoxicity. Physico-chemical parameters were calculated using WIN CAChe 6.1. Stepwise multiple linear regression analysis was carried out to derive QSAR models which were further evaluated for statistical significance and predictive power by internal and external validation. The selected best QSAR models showed correlation coefficient R of 0.914 and 0.901, and cross-validated squared correlation coefficient Q ² of 0.685 and 0.691 for anti-HIV activity and cytotoxicity, respectively. The developed significant QSAR model indicates that hydrophobicity of the whole molecule plays an important role in the anti-HIV activity and cytotoxicity of pyrimidinyl and triazinyl amine derivatives. When hydrophobicity is increased, anti-HIV activity of the present series of compounds is decreased leading to high cytotoxicity.     

A Novel and Expedient Synthesis of 7‐Pyrimidinylpyrimido[4,5‐d]pyrimidinones

A novel and efficient procedure for the synthesis of new 7‐pyrimidinylpyrimido[4,5‐d]pyrimidinone derivatives was elaborated via the base‐promoted cyclodimerization reaction of 5‐[(dimethylamino)methylidene]‐6‐iminopyrimidine‐2,4(1H,3H)‐dione hydrochlorides. In an analogous manner, a 2‐thioxo analog was prepared starting with the corresponding 2‐thioxopyrimidin‐4‐one.