A Convenient Synthesis of 2,5 (1H,3H)-Tetrahydroquinazolinedione Using Lanthanum Chloride as the Catalyst

In the past decade,4-aryl-3,4-dihydropyrimidine derivatives have exhibited important pharmacological properties, e.g. as the integral backbones of several calcium channel blockers, antihypertensive agents, alpha-1a-antagonists, and neuropeptide Y (NPY) antagonists^[1]. Several lead compounds were developed that are equal in potency and duration of antihypertensive activity to classical and second-generation dihydropyridine drugs^[2].     

双环笼状磷酸酯衍生物的合成(Ⅴ)——1-氧代-1-磷杂-2,6,7-三氧杂双环[2,2,2]-4-取代酰基辛烷的合成

本文利用1-氧代-1-磷杂-2,6,7-二氧杂双环[2,2,2]-4-氯甲酰基辛烷3和硫醇、乙二胺、乙醇胺及一些具有生理活性的杂环化合物反应,合成了13种未见文献报道的化合物4_a-n。发现化合物3与8-羟基喹啉作用生成的是水合物。讨论了可能的结构。3与氨作用得到相应的酰胺,合成的化合物均经元素分析、IR和¹HNMR证实其结构。本文还研究了部分化合物的MS裂解规律。对部分化合物的生物活性初测表明,化合物4_j具有良好的杀菌活性,而无明显的杀虫活性。     

Synthesis of Phosphorus Derivatives of Pyrazolo[3,4-d]pyrimidine

Pyrazolo[3.4-d]pyrimidines are of considerable chemical and pharmacological importance as purine analogs^[1]. Various related compounds of these also show anti-tumor, anti-leukemic and antiviral activities^[2,3]. In addition,α-aminoalkylphosphonic acid are well known for their wide range of biological activities. They serve in agrochemistry as antifungal agents, herbicides and plant regulators^[4]. Recently, it was discovered that some derivatives of α-aminoalkylphosphonic acid also exhibit good antiphytoviral activity^[5]. As an extension of our studies on plant virucides, we now wish to report the synthesis of some novel phosphorus derivatives of pyrazolo[3,4-d]pyrimidine-6-ones 4,which may have antiviral activity.     

Syntheses of 3-[5-Methyl-1-(4-Methylphenyl)-1,2,3-Triazol-4-yl]-6-Substituted-s-Triazolo[3,4-b]-1,3,4-Thiadiazoles

1,2,3-Triazole derivatives have been reported as inhibiting tumor proliferation, invasion, and metastasis^[1]. The fused l,3,4-triazolo[3,4-b]-1,3,4-thiadiazoles derivatives show various biological effects such as antifungal^[2], antibacterial, hypotensive and CNS depressant activities^[3]. We have reported several 6-aryl-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazolo[3,4-b]-1,3,4-thiadiazoles in the previous paper^[4]. The novel 6-aryl-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazolo[2,4-b]-1,3,4-thiadiazoles 6a-j have been synthesized by the condensation of 4-amino-5-mercapto-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazole 5 with various aromatic carboxylic acids in the presence of phosphorus oxychloride. The mercaptotriazole 5 was prepared from 4,the latter being prepared from 1 throng 2 and 3. The title compounds 6 were depicted in scheme 1. The structures of these compounds were established by elemental analysis, NMR, MS and IR techniques.     

Imidazo[2,1‐b]thiazoles,imidazo[2,1‐b]imidazoles and Pyrrolo[1,2‐c]imidazoles. synthesis,structure and evaluation of benzodiazepine receptor binding

As a continuation of our studies on bicyclic heterocycles with benzodiazepine receptor affinity, derivatives with a 5:5 bicyclic skeleton, namely imidazo[2,1‐b]thiazoles, imidazo[2,1‐b]imidazoles and pyrrolo[1,2‐c]imidazoles were prepared. The compounds possessed an aromatic substituent with different spatial arrangement and distance to the bicyclic skeleton. X‐ray structure analysis was performed for Z‐2‐(4‐chlorobenzylidene)‐5,5‐diphenyl‐2,3,5,6‐tetrahydroimidazo[2,1‐b]imidazoline‐3,6‐dione ( 6a ) and 5‐amino‐6‐cyano‐7‐phenyl‐1‐oxo‐3‐thioxo‐2,3‐dihydro‐1H‐pyrrolo[1,2‐c]imidazole ( 20a ). In contrast to the previously described arylideneimidazo[2,1‐b]thiazepinones the smaller heterocyclic ring systems investigated in this study were devoid of meaningful benzodiazepine receptor affinity as well as anti‐convulsant activity.     

Theoretical study of tricyclo[3,3,1,1]decane, tricyclo[3,3,1,1]decsilane molecules and their halogen derivatives, C10H12X4 and Si10H12X4 (X=F, Cl, Br, I)

The B3LYP/3-21G* ab initio molecular orbital method from the program package was applied to study tricyclo[3,3,1,1^3,7]decane and tricyclo[3,3,1,1^3,7]decsilane molecules and their halogen derivatives (1,3,5,7-tetrahalotricyclo[3,3,1,1^3,7]decane and 1,3,5,7-tetrahalotricyclo[3,3,1,1^3,7]decsilane, C₁₀H₁₂X₄ and Si₁₀H₁₂X₄ respectively). The optimized structures of these compounds were obtained. Ionization potentials, HOMO and LUMO energies, energy gaps, heats of formation, atomization energies and vibration frequencies were calculated. The calculations indicate that these molecules are stable and have T_d symmetry. Tricyclo[3,3,1,1^3,7]decsilane and its halogen derivatives (Si₁₀H₁₂X₄) are found to have higher conductivity than tricyclo[3,3,1,1^3,7]decane and its halogen derivatives (C₁₀H₁₂X₄). 1,3,5,7-Tetrafluorotricyclo[3,3,1,1^3,7]decane (C₁₀H₁₂F₄) and 1,3,5,7-tetrafluorotricyclo[3,3,1,1^3,7]decsilane (Si₁₀H₁₂F₄) were found to be the easiest compounds to form and the most difficult to dissociate of all 1,3,5,7-tetrahalotricyclo[3,3,1,1^3,7]decane and 1,3,5,7-tetrahalotricyclo[3,3,1,1^3,7]decsilane compounds, respectively.     

The Preparation and Characterization of Several Metal Phosphate Catalysts

Metal phosphates have been widely used as catalysts in many organic reactions for their acid-base and redox properties^[1,2]. Their structure and properties are affected greatly by the preparation method^[2-5]. AlPO₄ is one of the most important metal phosphates. There are many different phases of AlPO₄) that is, amorphous, crystalline and molecular sieve. The usual methods of preparation of AlPO₄ are described elsewhere^[1,3], i.e. gelification of a mixture of an aluminum salt (chloride, nitrate etc.) with orthophosphoric acid (or NaH₂PO₄) in the presence of a base. Ammonia, ethylene oxide, and propylene oxide are used as base mostly.     

邻甲氧基羰基苄氧基取代杯[4]芳烃衍生物的合成及其性能研究

杯芳烃是继冠醚、环糊精之后的第三代主体分子[1].据文献[2,3]报道,在杯[4]芳烃下沿酚氧原子上连接乙酸酯得到的四取代衍生物对Na+有很高的选择性,核磁与晶体结构研究均证实这是由于羧酸酯的羰基和酚氧基参与了对Na+的配位,而且配位基团所形成的包络空间大小与钠离子相匹配.一般认为,随着包络空间改变,对金属离子的识别作用会有所变化[4].但目前对这方面的工作并没有给予更多的重视.我们发现,用2-溴甲基苯甲酸甲酯与杯[4]芳烃反应,得到了一种新的四取代杯[4]芳烃衍生物[2]萃取研究结果表明,该化合物对钾离子有较好的选择性.此外,在合成该衍生物的过程中,还得到了另一新的二取代衍生物(3).     

A SIMPLE,EFFICIENT AND NEW METHOD FOR PREPARING AZO UREAS

Azo compounds are widely utilized as dyes and analytical reagents.They can also be used as materials for non-linear optics and for storage optical information in laser dish^[1]. Recently, many noteworthy studies have shown that azobenzene derivatives possess excellent optical memory and photoelectric properties^[2]. The preparation of ordinary azo compounds has been described in many references. However, those compounds generally bear alkyl or aryl groups on both sides of the azo linkage (-N=N-).     

Synthesis of 6-(6-/8-Substituted-4-Chloro-Quinoline-3-yl)-3-Aryl-s-Triazolo[3,4-b] -1,3,4-Thiadiazoles

A survey of literature^[1] revealed that s-triazolo[3,4-b]-1,3,4-thiadiazole has received much attention during recent years on account of its prominent utilization as antifugal, anti-inflammatory, analgsic and anthelmintic agents probably resulting from its planner and compact structure. In the course of the study of this ring system, we previously described a series of 3,6-disubstituted-s-triazolo[3,4-b]-1,3,4-thiadiazoles which exhibited antibacterial, herbicidal and plant growth regulative activities. It is well known that quinoline derivatives are associatied with broad spectrum biological activities^[2].     

An enantioselective NMR shift reagent for cationic aromatics

[structure: see text] The water-soluble tetra l-prolinylmethyl derivative of a tetrasulfonated calix[4]resorcarene is an effective chiral NMR solvating agent for compounds with bicyclic aromatic or indole rings. Complexation of bicyclic substrates with the calix[4]resorcarene is likely promoted by hydrophobic effects. The bicyclic substrates have larger association constants with the calix[4]resorcarene than similar phenyl-containing compounds. Substantial enantiomeric discrimination is observed for several resonances in the (1)H NMR spectra of these substrates.     

A New Synthesis of 4, 4-Diaryl/Diheteroaryl-3-butenyl Derivatives of Nipecotic Acids as GABA Transporter Inhibitors

A new method for the synthesis of 4, 4-diaryl/diheteroaryl-3-butenyl derivatives of nipecotic acid as GABA transporter inhibitors is described. The key intermediates 4-tosyl-1, 1-diaryl/diheteroaryl-1-butene 10a-d were synthesized by Wittig reaction, and followed by alkylation with （R）-3-piperidinecarboxylate. The resulting N-cycloalkylated amino acid esters 11a-d were saponified and then acidified to get the target compounds 1a-d. The preliminary bioassays showed that la-d exhibited excellent inhibition of [3H]-GABA uptake in vitro of culture cells.     

Synthesis and Anticancer Activities of Some Thiazole Derivatives

In this study, 2-substituted 4-[3/4-(4-arylthiazole-2-yl)aminophenyl]thiazole derivatives and 2-[4-[2-substituted 4-methylthiazole-5-yl]thiazole-2-yl]amino-5-arylidenethiazoline-4-one derivatives have been synthesized. The cytotoxic and/or growth inhibitory effects of the 16 selected compounds were evaluated in vitro against approximately 66 human tumor cell lines derived from nine neoplastic diseases. Some of the compounds were found to act as anticancer agents.     

Fingerprint patterns from laser-induced Azido photochemistry of spin-labeled photoaffinity ATP analogs in matrix-assisted laser desorption/ionization mass spectrometry

The photochemical reaction of azide derivatives induced by ultraviolet (UV) laser in matrix-assisted laser desorption/ionization mass spectrometry (MALDI) is reported. A novel synthesized class of azide aromatic derivatives, spin-labeled photoaffinity non-nucleoside adenosine triphosphate (ATP) analogs which are useful probes in study of muscle contraction mechanism, is used in this investigation. In the negative ion MALDI spectra of these ATP analogs, “fingerprint” peaks corresponding to [M − 10 − 1]⁻, [M − 12 − 1]⁻, [M − 16 − 1]⁻, [M − 26 − 1]⁻, [M − 28 − 1]⁻, [M − 41 − 1]⁻, and [M − 42 − 1]⁻ were observed with relative intensities depending on the MALDI matrix. Only the [M − 16 − 1]⁻ is present in the similar mass spectra of the analog in which the azido group is replaced by a hydrogen. A model is suggested for the photochemical reactions of azide derivatives under UV laser irradiation. The photoreaction fingerprint information is diagnostically useful in characterization of azido compounds, especially for spin-labeled photoaffinity non-nucleoside ATP analogs.     

The Synthesis and Crystal Structure of Triphenyltin-2-(l,1-dithioalkyl)methylene-3-oxo-5-aryl-4-pentenicate

Triorganotin compounds are a kind of organotin complexes with high biological activities. Some of triphenyltin derivatives such as triphenyltin acetate and triphenyltin hydroxide have been used as agricultural chemicals^[1]. α-Oxo ketene dithioacetals is a kind of important polyfunctionai intermediates in organic synthesis and is widely studied in recent years^[2]. Some of α-oxo ketene dithioacetal derivatives, such as 1,3-dithio-2-cyclopentylene-dithiopropylacrylate has also been used as agricultural chemicals. But it is no reports about the work combined both trialkyltin derivatives and α-oxo ketene dithioacetals together.     

Gold‐ or Platinum‐Catalyzed Cascade Processes of Alkynol Derivatives Involving Hydroalkoxylation Reactions Followed by Prins‐Type Cyclizations

An efficient method for the synthesis of [3.3.1]bicyclic compounds from easily available alkynol derivatives has been developed. The reaction is based on a gold‐ or platinum‐catalyzed tandem process that involves an intramolecular hydroalkoxylation of a triple bond followed by a Prins‐type cyclization. The reaction has been carried out with differently substituted alkynol derivatives and oxygen‐, nitrogen‐, and carbon‐centered nucleophiles. The incorporation of halogen atoms as nucleophiles and elimination reactions has also been studied. Enantiomerically pure [3.3.1]bicyclic systems were easily synthesized from the chiral pool.     

The Synthesis of Ferrocenyl Compounds with Nonlinear Optical Properties

There is currently considerable interest in the synthesis of new material with large second-order optical nonlinearities^[1-2]. Ferrocenyl derivatives that we synthesized should offer the nonlinear optical properties because they possess (-donor acceptor interactions and non-centrosymmetry. In these compounds, ferrocenyl moiety is strong donor and pyridinium moiety can provide low-lying (^* acceptor orbitals. Furthermore, these ferrocenyl compounds may also be used in preparation of self-assembled monolayers (SAMs)^[3] due to their long alkyl chain that can be anchored on metal oxide by carboxylic group. The synthesis of ferrocenyl derivatives is shown in Scheme 1.     

Thermal cycloaddition of carbonyl compounds to a stable cyclobutadiene

In contrast to acid chlorides which undergo addition to 1 to form cyclobutene derivatives 4, aldehydes react with the same antiaromatic starting compound 1 to give the [4+2]-cycloaddition product 5. Activated ketones such as 1,1,1-trifluoroacetone, biacetyl, and acetyl cyanide undergo a clean cycloaddition reaction to tricyclic compounds (1 + 6a?c → 9a?c), whereas trioxoindane yields a bicyclic product (1 + 6d → 8d).     

Water-soluble calix[4]resorcarenes as enantioselective NMR shift reagents for aromatic compounds

A tetra L-prolinylmethyl derivative of a tetra-sulfonated calix[4]resorcarene (1) is an effective chiral NMR solvating agent for water-soluble compounds with phenyl, pyridyl, bicyclic aromatic, or indole rings. These aromatic compounds form host-guest complexes with the calix[4]resorcarene in water. Complexation of substrates with the calix[4]resorcarene is likely promoted by hydrophobic effects, and bicyclic substrates have association constants with the calix[4]resorcarene larger than those of similar phenyl-containing compounds. Aromatic resonances of the substrates show substantial upfield shifts because of shielding from the aromatic rings of the calix[4]resorcarene, and several resonances in the 1H NMR spectra typically exhibit enantiomeric discrimination. The extent of enantiomeric discrimination depends in part on interactions of the substituent groups of the substrates with the prolinylmethyl groups of the calix[4]resorcarene. The effectiveness of a calix[4]resorcarene prepared from N-methyl-L-alanine (2) as a chiral NMR discriminating agent is compared to the L-prolinylmethyl derivative.