Synthesis of 4-(4-phenyl-3-pyrazolyl)-4H-1,2,4-triazoles

4-(4-PhenyI-3-pyrazolyl)-4H-1,2,4-triazoles and 4-phenyl-5-(4H-1,2,4-triazol4-yl)-3-pyrazolols were prepared by the reaction of formylhydrazine on α-phenyl-α-cyanoacetaldehydes and ethyl α-phenyl-α-cyanoacetates.     

Kinetics and mechanism of benzyl <Emphasis Type="Italic">para</Emphasis>-chlorophenyl ketone oxidation

The oxidation of benzyl para-chlorophenyl ketone in chlorobenzene at 100°C occurs through the formation of short chains. Non-peroxide reaction products (1-(4-chlorophenyl)-2-hydroxy-2-phenyl-1-ethanone, para-chlorobenzyl, benzaldehyde, and para-chlorobenzoic acid) are formed not only by the transformation of hydroperoxide (1-(4-chlorophenyl)-2-hydroxy-2-phenyl-1-ethanone) but also (or solely) through the recombination of α-ketoperoxyl radicals with or without chain termination. α-Hydroperoxide decomposes predominantly through a heterolytic route to form para-chlorobenzoic acid and benzaldehyde. Benzaldehyde and 1-(4-chlorophenyl)-2-hydroxy-2-phenyl-1-ethanone undergo radical chain oxidation in the reaction medium to form benzoic acid (benzaldehyde), para-chlorobenzyl, and benzoic and para-chlorobenzoic acids (1-(4-chlorophenyl)-2-hydroxy-2-phenyl-1-ethanone). The homolytic decomposition of α-hydroperoxy ketone and α-hydroxy-α-hydroperoxy ketone causes the self-acceleration of the process and affords 1-(4-chlorophenyl)-2-hydroxy-2-phenyl-1-ethanone or, to a lesser extent, benzaldehyde and para-chlorobenzoic acid (α-hydroperoxy ketone). para-Chlorobenzoic acid substantially accelerates the heterolytic decomposition of α-hydroxy-α-hydroperoxy ketone and the oxidation of benzyl para-chlorophenyl ketone with peroxy acids to ester according to the Baeyer-Villiger mechanism. The rate constants of the main steps of the process and kinetic parameters are calculated by solving the inverse kinetic problem.     

Studies on the synthesis of amino acids XIII. Dibenzylation of 2-phenyl-2-oxazolin-5-one

4,4-Dibenzyl-2-phenyl-2-oxazollin-5-ones are prepared by one step reaction of 2-phenyl-2-oxazolin-5-one with magnesium methyl carbonate (MMC) and benzylhalides. It is a novel and convenient method for the synthesis of α,α-disubstituted α-amino acids by hydrolysis of 4,4-dibenzyl-2-phenyl-2-oxazolin-5-ones.     

α,ω-Dihydroxyalkan-α,α-diphosphonsäuren durch Desaminierung von ω-Aminoalkandiphosphonsäuren

α,ω-Dihydroxyalkane-α,α-diphosphonic Acids by Desamination of ω-Aminoalkanediphosphonic Acids The title compounds represent a new group of complexing diphosphonic acids which are synthesized by desamination of ω-amino-α-hydroxyalkane-α,α-diphosphonic acids. In case of α,ω-dihydroxypropane-α,α-diphosphonic acid ( 1 ) a phosphonylated phostone is formed by dehydration. In contrast, the ω-phenyl drivative of ( 1 ) yields in a smooth reaction under the same conditions 2-hydroxy-5-phenyl-3-phosphono-1.2-oxaphosphol-3-en-2-oxide ( 6 ).     

Chelate von β-Dicarbonylverbindungen und ihren Derivaten. XV. Komplexchemische Reaktivität von β-Mercaptovinylaldehyden

The reactivity of α-phenyl-β-mercaptocinnamaldehyde and α-(2-pyridyl)-β-mercaptocinnamaldehyde towards thiophilic metals was studied and some complexes of nickel, cobalt, copper, palladium, zinc, lead and mercury with these ligands were prepared. The chemical bonding in the complexes was examined by IR spectroscopy. The reaction of the Bis(α-phenyl-β-mercaptocinnamaldehydato)-nickel with amines gave the corresponding aldimine chelates, by the action of hydrogen sulfide the nickel chelate of α-phenyl-β-mercaptocinnamthioaldehyde was formed.     

基于Ugi反应的新型鱼尼丁受体杀虫剂的设计、合成及生物活性

利用Ugi 反应设计合成了一系列未见文献报道的α-苯基-α-酰胺基-酰胺类化合物, 所有化合物均通过 ¹H NMR谱、元素分析和高分辨质谱表征确定. 初步的生物活性测试结果表明, 在浓度为200 mg/L时, 化合物7h对粘虫有一定抑制活性; 在浓度为50 mg/L时, 化合物7q对苹果轮纹病菌、化合物7e对小麦赤霉菌有一定的抑菌活性.     

New telechelic polymers and sequential copolymers by polyfunctional initiator-transfer agents (inifers). XXX. Synthesis and quantitative terminal functionalization of α,ω-diarylpolyisobutylenes

Novel aromatic-telechelic polyisobutylenes were prepared and characterized: α,ω-diphenylpolyisobutylene, α-phenyl-ω-tolylpolyisobutylene, and α,ωditolylpolyisobutylene. The syntheses involved the preparation of asymmetric telechelic prepolymers (α-phenyl-ω-tert-chloropolyisobutylene and α-tolyl-ω-tert-chloropolyisobutylene) by the minifer method and quantitative alkylation of benzene and toluene by the prepolymer. The terminal aromatic rings of these telechelic polyisobutylenes were quantitatively nitrated, acetylated, and chlorosulfonated and a series of further novel telechelic products was obtained. Characterization of these derivatives provided additional proof for the telechelic structure of the starting prepolymers. The quantitative reduction of nitroaryl-telechelic polyisobutylene by SnCl₂/HCl led to aminoaryl-telechelic polyisobutylene which was used to cure bisphenol-A diglycidyl ether. These new flexible epoxy networks exhibited outstanding heat and hydrolytic stability combined with satisfactory mechanical properties.     

Synthesis of Polymers by Using Fluorene. VI. Free-Radical and Anionic Polymerizations of 9-Fluorenyl and 9-Phenyl-9-fluorenyl Methacrylates

9-Fluorenyl (FMA) and 9-phenyl-9-fluorenyl methacrylates (PFMA) were prepared from methacryloyl chloride with 9-fluorenol and from silver methacrylate with 9-phenyl-9-fluorenyl chloride, respectively. The polymerizations of FMA and PFMA were studied by using α,α′-azobisisobutyronitrile (AIBN), n-butyllithium (n-BuLi), and n-BuLi-(?)-sparteine (Sp) complex in toluene and tetrahydrofuran (THF). Only PFMA polymers obtained with the n-BuLi-Sp complex showed a specific rotation ([α]_D ²¹ ?3 to ?16° in THF).

The number-average molecular weights of the FMA and PFMA polymers were 7 700-16 900 and 1 400-4 700, respectively.     

Reactions of acetylenic ketones with methyl α-naphthylacetate. A synthesis of l-amino-2-pyridone derivatives

Reactions of acetylenic ketones (Ia-f) with methyl α-naphthylacetate in the presence of sodium methoxide gave the corresponding 6-aryl-3-α-naphthyl-4-phenyl-2-pyrones (IIa-f) which upon refluxing with hydrazine hydrate in ethanol gave the corresponding 1-amino-2-pyridone derivatives (VIa-f). The structure of the products was established by chemical and spectroscopic evidence.     

The Preparation of 4,5-Dihydro-5-Phenyl-5-(2-Phenylethenyl)Isoxazoles, 4,5-Dihydro-5-Methyl-5-(2-Phenylethenyl)Isoxazoles,or 4,5-Dihydro-5,5-DI-(2-Phenylethenyl)Isoxazoles from Dilithiated C(α),O-Oximes and Select α,β–-Unsaturated Ketones

C(α),O-oximes were dilithiated with lithium diisopropylamide and condensed with three α,β-unsaturated ketones: (2E)-1,3-diphenyl-2-propen-1-one, or (1E, 4E)-1,5-diphenyl-1,4-pentadien-3-one, or (3E)-4-phenyl-3-buten-2-one, followed by immediate acid cyclization to variously substituted 4,5-dihydroisoxazoles: 4,5-dihydro-5-phenyl-5-(2-phenylethenyl)isoxazoles, 4,5-dihydro-5-methyl-5-(2-phenylethenyl)isoxazoles, or 4,5-dihydro-5,5-di-(2-phenylethenyl)-isoxazoles.     

Pyrimidines. 24. Analogues and derivatives of 2-amino-5-bromo-6-phenyl-4(3H)-pyrimidinone (ABPP)

Preparation of a number of derivatives of 2-amino-5-bromo-6-phenyl-4(3H)-pyrimidinone (ABPP) including the 2-dialkylaminoalkylamino-, 2-hydroxyalkylamino-, 2-ethoxycarbonylamino- and 2-alkylaminocarbonyl-amino- groups substituted on the pyrimidine ring as well as preparation of 1-(alkylaminoalkyl)-4,6-dioxo-8-phenyl-2,3,4,6-tetrahydro-1H-pyrimido[1,2-α]pyrimidines and 3,5-dioxo-7-phenyl-1,2,3,5-tetrahydroimidazo-[1,2-α]pyrimidines with or without the bromo-substitution are reported.     

Synthesis of bis-3-alkyl-5-arylhydantoins and bis-3-alkyl-5-arylthiohydantoins separated by two and four carbon atoms

Synthesis of 1,2- and 1,4-bis-thiohydantoins and hydantoins employing ethylenediamine and 1,4-diaminobutane as spacers is described. Compounds containing a two carbon bridge were synthesized by alkylation of ethylenediamine with two equivalents of N-t-butyl-α-(p-toluenesulfonyloxy)phenylacetamide 3 . The phenyl isothiocyanate adduct of 3 cyclized in refluxing toluene to form 1a . Other isothiocyanate or isocyanate adducts derived from alkylation product 4 required hydrolysis to induce cyclization. Compounds 1b-1f were obtained in this way. Compounds with a four carbon bridge were obtained by reaction of two equivalents of methyl α-bromophenyl acetate and 1,4-diaminobutane to produce N,N'-bis-[(α-phenyl-α-methoxycarbonyl)methyl]butylenediamine 6 . The isothiocyanate or isocyanate adducts from 6 cyclized, without hydrolysis, to form compounds 2a-2e .     

New Synthetic Methodology for The Preparation of Substituted 1-Aryl-1-Pyridylamlnomethanephosphonic Acid Esters

Esters of 1-phenyl-1-pyridylaminomethanephosphonates generally cannot, or only in poor yields be prepared by the usual methods by treatment of the appropriate Schiff base with diethyl or diphenyl phosphite. However, it was found that these phosphonates are readily available by treatment of N, N¹-dipyridyl-α, α-diaminotoluenes in an Arbuzov-type reaction with BF₃′O(Et)₂.     

The Structure and Spectroscopy of α-Hydroxyphosphonates

Abstract

α-Hydroxyphosphonates are important intermediates in the preparation of various organophosphorus compounds. Methods for their preparation have been described.¹ We now report new aspects of their structure and spectroscopy. In the solid state, O,O-dimethyl α-hydroxy-α-phenyl-β-chloroethylphosphonate has been shown by X-ray diffraction studies to consist of hydrogen-bonded dimers with a hydrosen-bond length between the phosphoryl oxygen and hydroxyl hydrogen atom of 1.74 Å. The P=0 bond is relatively short (1.463).     

Isolation and structural characterization of a low-molecular-weight pectic polysaccharide SHPPB-1 isolated from sunflower heads

A novel low-molecular-weight pectic polysaccharide was isolated from sunflower heads that are a useless side product produced from sunflower oil processing. The low-molecular-weight pectic polysaccharide was purified by using an optimized four-step procedure and named as SHPPB-1. The molecular weight of SHPPB-1 is about 1.69× 10⁴ Da. Structure characterizations of SHPPB-1 by monosaccharide composition, methylation analysis, and Fourier transform infrared (FT-IR) spectroscopy showed that SHPPB-1 is consisted of 1,4-linked α-D-GalpA and 1,4-linked 2-OAc-5-COOMe-α-D-GalpA with rare α/β-D-Rhap, α/β-D-Manp, and α/β-D-GalpA. This was combined with NMR spectroscopic analysis to propose a structure of SHPPB-1 as: →4)-[α/β-D-monosaccharide-(1→3)]-α-D-GalpA-(1→4)-2-OAc-5-COOMe-α-D-GalpA-(1→ .     

The [2,3]-sigmatropic rearrangement of propargyl benzenesulphinates to allenyl phenyl sulphones

α-Methyl-, α-phenyl-, α,α -dimethyl-, and α-ethyl-α-methylpropargyl benzenesulphinates were found to undergo thermal rearrangement in high yields to sulphones, accompanied by a simultaneous acetylene-allene isomerization. The allenic sulphones produced by the rearrangement of the α-monosubstituted propargyl esters underwent further rearrangement under the reaction conditions, to γ-substituted propargyl phenyl sulphones, by way of a base-catalyzed [1,3] - prototropic shift. A kinetic study of the rearrangement reaction was carried out using two different esters. This study revealed that the rearrangement exhibited a relatively low sensitivity to the effect of solvent ionizing power and substituents. These data and other pertinent evidence suggest a concerted [2,3] - sigmatropic rearrangement.     

Direct introduction of glycine/mercaptoacetic acid units into electron-poor alkenes: a novel route to functionally rich α-amino/α-mercapto acids

The first example of an operationally simple direct introduction of glycine/mercaptoacetic acid units into electron-poor alkenes is reported. In this protocol, Lewis acid-catalyzed Michael addition of activated glycine or mercaptoacetic acid, that is 2-phenyl-1,3-oxazol-5-one or 2-methyl-2-phenyl-1,3-oxathiolan-5-one, to various electron-poor alkenes in water/1,4-dioxane (1:2, v/v) solvent system diastereoselectively affords the corresponding functionally rich α-amino acids or α-mercapto acids, respectively, in high yields at ambient temperature.     

一锅法合成新型7-苯基-1,4,5,6,7,8-六氢喹啉酮衍生物

以5-苯基-1,3-环己二酮,醛,乙酰乙酸乙酯(或乙酰丙酮)和乙酸铵为原料,在无水乙醇中经一锅反应合成了14个新型的7-苯基-1,4,5,6,7,8-六氢喹啉酮衍生物,总收率85%~95%,其结构经¹H NMR, ¹³C NMR, IR和HR-MS表征。采用X-ray单晶衍射研究了2-甲基-4,7-二苯基-5-氧代-1,4,5,6,7,8-六氢喹啉顺反异构体(5a和5a′)的晶体结构。结果表明：5a空间群为C2/c, a=9.458 35(19) ,b=19.789 0(4) ,c=11.040 9(2) , α=90°, β=105.614(2)°, γ=90°,V=1 990.28(7) ³, Z=4, μ=0.673 mm^-1, F(000)=824; 5a′空间群为C2/c, a=9.770 2(5) , b=19.981 0(10) , c=10.430 1(4) , α=90°, β=98.361(5)°, γ=90°, V=2 014.51(17) ³, Z=4, μ=0.665 mm^-1, F(000)=824。     

Synthesis,chiroptical properties and absolute configuration of α-phenylglycidic acid

The (+)- and (-) enantiomers of potassium α-phenylglycidate, an irreversible inhibitor of the enzyme mandelate racemase, were synthesized by resolution of the diastereomeric esters with R-(-)-2-octanol. Base-catalyzed ring-opening of the resolved α-phenylglycidate esters gave the enantiomers of 2,3-dihydroxy-2-phenylpropanoic acid, also obtained by resolution of the racemic dihydroxy acid using ephedrine. A comparison of the chiroptical properties of the esters of α-phenylglycidic and 2,3-dihydroxy-2-phenylpropanoic acids with those of the structurally similar atrolactic and mandelic acids and their 2-methoxy-derivatives showed that the (-)-methyl 2,3-dihydroxy-2-phenylpropanoate corresponding to the (+)-enantiomer of potassium α-phenylglycidate, as well as the esters of α-phenylglycidic acid derived from the same (+)-potassium salt, were all configurationally related to S-(+)-atrolactic and mandelic acids. The configurational assignments made on the basis of the chiroptical data were confirmed by lithium aluminum hydride reduction of the (-)-2-octyl S- and R-α-phenylglycidates, which led exclusively to the R-(-)- and S-(+)-2-phenyl-1, 2-propanediols, respectively, previously related configurationally to R-(-)- and S-(+)-atrolactic acids.     

Efficient preparation of enantiomerically pure α-aryl-α-trifluoromethylglycines via Auto Seeded Programmed Polythermic Preferential Crystallization of 5-aryl-5-trifluoromethylhydantoins

Both pure enantiomers of α-phenyl- (or α-(p-methoxyphenyl))-α-trifluoromethyl-glycine and their corresponding methyl esters were obtained on a preparative scale using the following four-step sequence: the preparation of 5-aryl-5-trifluoromethylhydantoins by a Bücherer-Bergs reaction starting from trifluoromethyl aryl ketones, optical resolution by Auto Seeded Programmed Polythermic Preferential Crystallization (AS3PC), basic hydrolysis of the enantiopure hydantoins by means of aqueous barium hydroxide, and esterification of the amino acids with trimethylsilyldiazomethane. Hydantoins 5 and 6 were proven to crystallize as conglomerates using first second harmonic generation and then X-ray powder diffraction. The absolute stereochemistry of (+)-5-phenyl-5-trifluoromethylhydantoin 5b was established to be (S) by X-ray diffraction analysis on a single-crystal.