新法合成6-烷氧基和6-氨基鸟嘌呤核苷衍生物

以鸟嘌呤为核苷为原料,经酯化、再在缩合剂4-氯苯磷酰二氯和1,2,4-三氮唑存在下与吡啶反应,得鸟嘌呤核苷N-6吡啶盐中间体(2),该中间体2分别与NH~3/CH~3OH、Et~3N/CH~3OH、Et~EN/CH~3CH~2OH在室温反应,可方便的合成6-NH~2、6-OCH~3和6-OCH~2CH~3-9-(β-D-呋喃核糖)鸟嘌呤衍生物。     

N—取代苯基—N‘—（2—甲基苯氧乙酰基）氨基脲的合成及鉴定

以无机碱作催化剂,用不同的Ｎ－取代三氯乙酰苯胺与２－甲基苯氧乙酰肼反应,合成了５种取代氨基脲,产率达８２％以上。     

One‐pot Synthesis,Crystal structure,and Bioactivity of N‐Phenoxyacetyl‐2,4,5‐trisubstituted‐1,3‐oxazolidines

N‐phenoxyacetyl‐1,3‐oxazolidine derivatives were synthesized by the cyclization and acylation with β‐amino alcohol, ketone, and phenoxyacetyl chloride as the starting materials. All compounds were characterized by IR, ¹H NMR, ¹³C NMR, ESI‐MS, and elemental analysis. The configuration of 4a was determined by X‐ray crystallography. The preliminary biological tests showed that all products could protect soybean against injury caused by 2,4‐D butylate to some extent.     

Synthesis of Novel Tricyclic 1,5‐Benzothiazepine Derivatives Bearing Quinoline Moiety via [2 + 2] Cycloaddition Reaction

A series of new tricyclic 1,5‐benzothiazepine derivatives were synthesized by the reaction of 1,5‐benzothiazepine containing 2‐phenoxy‐quinoline with chloracetyl chloride and phenoxyacetyl chloride. The structures of the target compounds were confirmed by IR, ¹H NMR MS, and elemental analysis.     

Reactions of Imidates with Phenoxyacetyl Chloride

The reactions of imidates including cyclic imidates, oxazolines and dihydrooxazine with phenoxyacetyl chloride, were investigated. The results indicate that diacylamide or acylamide was generated from N-phenoxyacetylated imidates, while cyclic imidate oxazolines underwent a ring-opening reaction to yield different amides depending on the reaction conditions. Even under non-nucleophilic conditions, no β-lactam-fused oxazoline derivative was obtained.     

Synthesis and antimicrobial activity of some new sugar-based monocyclic beta-lactams

The syntheses of some new sugar-based monocyclic beta-lactams possessing several other functionalities in addition to the carbohydrate moiety are described. The key step was the Staudinger [2+2] cycloaddition of chiral carbohydrate Schiff base 5 with phthalimidoacetyl chloride to yield the sugar-based monocyclic beta-lactam 6 as a single isomer. Treatment of protected beta-lactams 6 and 8 with methylhydrazine afforded the free amino beta-lactams 9 and 10. Acylation of these free amino beta-lactams with benzoyl, phenoxyacetyl, cinnamoyl and phenylacetyl chloride in the presence of pyridine afforded beta-lactams 11a-d and 12a-d. Some of these novel beta-lactams were found to be active against Staphilococcus citrus, Klebsiella pneumoniae, Escherichia coli and Bacillus subtilis.     

N-Phenoxyacetylated guanosine and adenosine phosphoramidites in the solid phase synthesis of oligoribonucleotides: Synthesis of a ribozyme sequence

Phosphoramidites for guanosine and adenosine nucleosides with phenoxyacetyl as N-acyl protecting group were prepared. These nucleoside phosphoramidites, together with previously reported uridine and N-benzoyl cytidine phosphoramidites have been applied to the efficient solid phase synthesis of a trideca and a nonadecaribonucleotide. The later molecule has the sequence corresponding to a ribozyme.     

Reaction of 2-alkoxy-2-methylthio-5,6-dihydro-4H-1,3-thiazines with phenoxyacetyl chloride

The reaction of 4-alkoxytetrahydro-1, 3-thiazine-2-thiones with methyl iodide and subsequent treatment of the resultant S-alkylation products by suitable sodium alcoholates yielded 4-alkoxy-2-methylthio-S, 6-dihydro-4H-1, 3-thiazines, which upon reaction with phenoxyacetyl chloride in the presence of triethylamine was stereospecifically converted into 4-alkoxy-6-methylthio-7-phenoxvcephams.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 557–560, April, 1996.     

超声波辐射固-液相转移催化下2,5-二取代-1,3,4-噻二唑和N-取代二酰肼的一锅法合成研究

采用超声波辐射与相转移催化联用技术, 4-甲基苯氧乙酰氯(4)和硫氰酸铵反应得到中间体芳氧乙酰基异硫氰酸酯5, 不经分离直接与芳氨基乙酰肼2反应, 一锅法制得了7个新的2,5-二取代-1,3,4-噻二唑7a～7g和9个新的N-取代二酰肼8a～8i, 并利用IR, ¹H NMR, ¹³C NMR, MS谱和元素分析对其结构进行了表征.     

头孢地尼的合成

头孢地尼的合成是用2－（2－氨基噻－4－基）－2－（Z）－（乙酰氧亚氨基）乙酰氯与7－氨基－3－乙烯基－3－头孢烯－4－羧酸二苯甲酯盐酸盐进行缩合,优化反应条件后,总收率为60％。     

Studies on Ion-molecule Reaction of Disubstituted Benzene with IonSystem of Acetyl Chloride in Gas Phase

IntroductionThe intramolecular function group interaction plays an important role in gas--phase ionmolecular reactions and the fragmentation reactions of its product ionsLI--12]. The fragmenta..non reactions of the odd--electron ions of benzoic acid[13], phenylacetyleneL"], phenylsulfide[15], nitrobenzene[16j, methoxybenzaldehyde["] and acetophenone["J obviously show theOrtho effect. The fragmentation properties of the protonated molecules and the adduct ions ofo, m, p- meth oxy - ac etop he…     

羧酸衍生物取代甲基苯基聚硅烷制备杂取代聚硅烷

以甲基苯基聚硅烷　(PhSiMe　) n为原料 ,在无水AlCl3 存在下 ,通过与酰氯、酸酐及酯的取代反应合成了氯代聚硅烷及一系列共聚物 .在乙酰氯的作用下 ,　(PhSiMe　) n上的苯基能够被近乎完全的取代而生成氯代聚硅烷 .一元酸酐 (乙酸酐和丙酸酐 )在用酰氧基部分取代聚硅烷上苯基的同时 ,进行得更多的还是Cl取代 .而顺丁烯二酸酐、邻苯二甲酸酐和乙酸乙酯则只进行不完全的Cl取代 ,根据分子活性的不同得到取代比率各不相同的共聚物 .初步分析了各反应的过程 ,讨论了影响反应的因素 ,同时对于各产物的荧光和紫外特性也进行了分析和讨论     

Stereospecific synthesis of a dl-gala-aminoquercitol derivative

A new aminoquercitol derivative was synthesized starting from 1,4-cyclohexadiene. Photooxygenation of cyclohexa-1,4-diene afforded anti-2,3-dioxabicyclo[2.2.2]oct-7-en-5-yl hydroperoxide as the main product. The formed hydroperoxy endoperoxide was reduced with LiAlH₄ to produce anti-2,3-dioxabicyclo[2.2.2]oct-7-en-5-ol. Protection of alcohol with acetyl chloride followed by reduction of the endoperoxide with thiourea, and then palladium-catalyzed ionization/cyclization reaction gave an oxazolidinone derivative. Hydrolysis of the oxazolidinone ring and acetylation gave an amino compound. Oxidation of the double bond in the amino compound with OsO₄ followed by acetylation gave the amino tetraacetate and removal of the acetate groups furnished the desired aminoquercitol whose exact configuration was determined by X-ray diffraction analysis.     

Formation of surface-bound acyl groups by reaction of acyl halides on ge(100)-2x1

We have investigated the reaction of a series of acyl halides, including acetyl chloride, acetyl bromide, acetyl-d3 chloride, benzoyl chloride, and pivaloyl chloride, on Ge(100)-2x1 with multiple internal reflection infrared (MIR-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT). Infrared spectra following saturation exposures of acetyl chloride and acetyl bromide to Ge(100)-2x1 at 310 K are nearly identical, both exhibiting strong nu(C=O) stretching peaks near 1685 cm-1 and no vibrational modes in the nu(Ge-H) region. These data provide strong evidence for the presence of a surface-bound acetyl group on Ge(100)-2x1, which results from a C-X dissociation reaction (where X=Cl, Br). For acetyl chloride, DFT calculations predict that the barrier to C-Cl dissociation is only 1 kcal/mol above a chlorine-bound precursor state and is considerably smaller than barriers leading to the [2+2] C=O cycloaddition and alpha-CH dissociation products. In addition to the C-X dissociation product, both infrared and photoelectron results point to the presence of a second structure for acetyl halides where the oxygen of the surface-bound acetyl group donates charge to a nearby surface atom. This interaction is not observed for benzoyl chloride and pivaloyl chloride.     

Solventless protocol for efficient bis-N-boc protection of adenosine, cytidine, and guanosine derivatives

A solvent-free reaction employing a simple low-energy ball mill apparatus converts the amino groups of adenosine, 2-deoxyadenosine, cytidine, 2-deoxycytidine, guanosine, and 2-deoxyguanosine as well as some of their ribosyl O-protected derivatives to the corresponding bis-N-Boc carbamates. In the case of guanosine compounds, the carbonyl group of the base moiety was also blocked as its O-Boc enol carbonate. A variation of this approach using transient in situ O-silylation permitted the preparation of bis-N-Boc nucleosides in which the sugar hydroxyls were unprotected. The ball mill reactions were rapid, convenient, and very high-yielding except in the case of the guanosine compounds. This highly efficient method protects the amino groups of these nucleosides with a base stable and acid labile group suitable for further synthetic manipulation.     

A Practical One‐Step Synthesis of 1,2‐Oxazoline Derivatives from Unprotected Sugars and Its Application to Chemoenzymatic β‐N‐Acetylglucosaminidation of Disialo‐oligosaccharide

A facile and practical method for synthesis of sugar oxazolines (=dihydrooxazoles) from the corresponding N‐acetyl‐2‐amino sugars has been developed by using 2‐chloro‐1,3‐dimethyl‐1H‐benzimidazol‐3‐ium chloride (CDMBI) as a dehydrative condensing agent. The intramolecular dehydrative reaction between the 2‐acetamido group and the anomeric OH group of unprotected N‐acetyl‐2‐amino sugars took place smoothly in H₂O, leading to the formation of a 1,2‐oxazoline (=4,5‐dihydrooxazole) moiety in good yield. Since the reaction proceeds in H₂O without using any protecting groups, the resulting oxazolines can be utilized as effective glycosyl donors for the subsequent enzymatic glycosylation. We have successfully demonstrated a highly efficient chemoenzymatic transglycosylation of a disialo‐oligosaccharide moiety to p‐nitrophenyl N‐acetylglucosaminide catalyzed by a mutant endo‐N‐acetylglucosaminidase without isolating disialo‐oligosaccharide oxazoline as synthetic intermediate.     

Heterocyclic X-azolopyridine intermediates

A series of heterocyclic coupling agents having tuned hydrophobic chains, has been prepared by reaction of diamino or hydroxy-aminopyridines and p-aminosalicylic acid. The acetylation of amino group and hydroxyl in oxazole derivatives showed a selectivity depending on wheter acetic anhydride or acetyl chloride was used. Correlations between structure and spectroscopic data, including related compounds previously described, are reported.     

Studies on mesoionic compounds—IV : Synthesis and reactions of 4-thiosydnone derivatives

Various 4-methylthiosydnones were prepared by the reaction of 3-substituted sydnones with DmSO and acetyl chloride, while the reaction with methyl phenyl sulfoxide and acetyl chloride gave 4-chlorosydnones. Treatment of 3-substituted sydnones with DmSO and methyl phenyl sulfoxide together with acetyl perchlorate, followed by refluxing with aqueous potassium chloride gave 4-methylthio- and 4-phenylthiosydnones via the corresponding 4-dimethyl- and 4-methylphenyl-sulfonium perchlorates, respectively. Oxidation of 4-methylthiosydnones with hydrogen peroxide gave 4-methyl-sulfinyl- and 4-methylsulfonylsydnones.     

The reaction of indolizines and acetylindolizines with trifluoromethylsulfenyl chloride

Two trifluoromethylsulfenyl groups were introduced into the 1,3 positions of indolizines by the reaction of trifluoromethylsulfenyl chloride with indolizine and its 2-methyl, 2-phenyl, 2-methyl-3-acetyl and 2-phenyl-3acetyl derivatives     

Chloracylierung und Bromacylierung von Carbonylverbindungen. II. Analyse der Nebenprodukte

Chloroacylation and bromoacylation of carbonyl compounds II. Structure of the by-products The structures of the by-products formed in the reaction between paraformaldehyde and acetyl chloride as well as between acetaldehyde and acetyl chloride are elucidated. Optimum conditions for a high yield of the (α-chloroalkyl) ester 1 were obtained by variation of structure and reaction parameters. A speculative reaction scheme of the formation of by-products is discussed.