2-(4-Sulfophenylsulfonyl)ethoxycarbonyl group: a new water-soluble N-protecting group and its application to solid phase peptide synthesis in water

Solid phase peptide synthesis is carried out in organic solvents, creating environmental problems after disposal. To avoid this problem, we aimed to perform solid phase peptide synthesis in water. A new water-soluble N-protecting group, 2-(4-sulfophenylsulfonyl)ethoxycarbonyl (Sps) group, was designed and Sps-amino acids were prepared. To evaluate the utility of this technique, Leu-enkephalin amide was prepared by solid phase synthesis using Sps-amino acids in water.     

A new reagent, 2-[phenyl(methyl)sulfonio]ethyl-4-nitro-phenylcarbonate tetrafluoroborate (Pms-ONp), for preparing water-soluble N-protected amino acids

Peptide syntheses are performed in various organic solvents, the disposal of which is an environmental problem. To avoid this problem, peptide synthesis in water using reagents of low toxicity is desirable. For peptide synthesis in water, we previously reported the design of a water-soluble N-protecting group, 2-[phenyl(methyl)sulfonio]ethoxycarbonyl tetrafluoroborate (Pms) group, but the introduction of this group onto sulfur-containing amino acids was problematic. Here, a new reagent, 2-[phenyl(methyl)sulfonio]ethyl-4-nitrophenylcarbonate tetrafluoroborate (Pms-ONp), has been designed and used to prepare Pms derivatives of sulfur-containing amino acids. Pms-Met was prepared and tested for the solid-phase synthesis of Met-enkephalin amide in water using a crosslinked ethoxylate acrylate resin.     

First synthesis of 2-[alkylamino(diethoxyphosphoryl)methyl]acrylic ethyl esters

The ethyl α-bromomethyl-β-(diethoxyphosphoryl)acrylic acid ester 9 has been prepared by addition of bromine to allylphosphonate 7 then dehydrobromination with DBU in acetonitrile. Reaction of allylic bromide 9 with primary amines in a bimolecular S_N2′-type mecanism in methanol at low temperature, gives rise to the 2-[alkylamino(diethoxyphosphoryl)methyl]acrylic acid ethyl esters 6.     

1-(2-Quinoxalyl)-, 1-[3,5-Di(trifluoromethyl)phenyl]-, 1-(2-Carboxyphenyl)-, and 1-Ethoxycarbonyl-4-oxo-4,5,6,7-tetrahydroindazoles

The corresponding 1-(2-quinoxalyl)-, 1-[3,5-di(trifluoromethyl)phenyl]-, and 1-ethoxycarbonyl-3-methyl-4-oxo-4,5,6,7-tetrahydroindazoles have been obtained from reactions of 2-acetyl-1,3-cyclohexanedione, its 5,5-dimethyl and 5-(2-furyl) derivatives, with 2-hydrazinoquinoxaline, 3,5-di(trifluoromethyl)phenylhydrazine, and ethoxycarbonylhydrazine. On interaction with ethoxycarbonylhydrazine the intermediate 2-[1-(-ethoxycarbonyl)hydrazino]ethylidene-1,3-cyclohexanediones were also isolated. From the potassium salt of 2-formyldimedone and 2-carboxyphenylhydrazine hydrochloride, 2-(2-carboxyphenyl)hydrazinomethylene-5,5-dimethyl-1,3-cyclohexanedione was obtained, the cyclization of which in ethanol in the presence of HCl led to 1-(2-carboxyphenyl)- and 1-(2-ethoxycarbonylphenyl)-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazole.     

Synthesis of （S）-2-（3-Arylacrylamido）-3-{4-[2-（5-methyl-2-phenyloxazol-4-yl）ethoxy]phenyl}propanoic Acids

The synthesis of （S）-2-（3-arylacrylamido）-3-{4-[2-（5-methyl-2-phenyloxazol-4-yl）etho- xy]phenyl}propanoic acids is described. Their structures were confirmed by ^1H-NMR.     

Synthesis and Crystal Structure of （Z）-Methyl-3-methoxy-2-{2-[（4-（E-3-p-tolylacryloyl）phenoxy）methyl]phenyl}acrylate

The title compound,(Z)-methyl-3-methoxy-2-{2-[(4-(E-3-p-tolylacryloyl)phenoxy)-methyl]phenyl}acrylate,was synthesized and determined by X-ray single-crystal diffraction. The crystal belongs to the triclinic system,space group P1 with a = 8.0157(8),b = 12.5748(13),c = 13.3768(14) ,α = 64.770(2),β = 75.720 (2),γ = 89.784(2)°,μ = 0.085 mm-1,Mr = 442.49,V = 1174.1(2) 3,Z = 2,Dc = 1.252 g/cm3,F(000) = 468,T = 294(2) K,R = 0.0603 and wR = 0.1498 for 2644 observed reflections with I 2σ(I). X-ray diffraction analysis reveals that the single crystal contains strong non-classical hydrogen bonds. The preliminary bioassay showed that the title compound exhibits inhibitory activity against the Pseudoperoniospora cubensis and Rhizoctonia solani at the test concentration of 200 mg/L.     

Synthesis and Antifungal Bioactivity of Methyl 2-Methoxyimino-2-{2-[(substituted benzylidene)aminooxymethyl]phenyl}acetate and 2-Methoxyimino-2-{2-[(substituted benzylidene)aminooxy-methyl]phenyl}-N-methylacetamide Derivatives

Ten methyl 2‐methoxyimino‐2‐{2‐[(substituted benzylidene)aminooxymethyl]phenyl}acetate and 2‐methoxy‐ imino‐2‐{2‐[(substituted benzylidene)aminooxymethyl]phenyl}‐N‐methylacetamide derivatives were synthesized. Structures of the new compounds were characterized by IR, ¹H NMR and GC‐MS data. These compounds at 10 µg/mL were tested in vitro against five pathogenic fungi, namely, Sclerotonia, Botrytis cinerea Pers, Gibberella zeae, Rhizoctorua solani and Pyricularia oryzae. Compounds G₅ , G₆ , G₇ and G₈ showed potent antifungal activities against Botrytis cinerea Pers, G₇ against Gibberella zeae and G₇ , G₈ against Rhizoctorua solani, respectively.     

A novel synthetic route for 2-[2-（2,2,2-trifluoroethoxy）phenoxy]ethanamine

2-[2-（2,2,2-Trifluoroethoxy）phenoxy]ethanamine is the key intermediate of Silodosin, the α1-adrenoceptor antagonist for the treatment of benign prostatic hyperplasia. In order to obtain this intermediate, we developed a novel synthetic route by utilizing 2- nitrochlorobenzene as the starting material via O-alkylation, reduction, diazotization, acidolysis, etherification, condensation and hydrazinolysis. The highlight of this method lies on its convenience and economy in accessing this intermediate. 2007 Guo Hua Chert. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.     

An improved procedure for the preparation of aminomethyl polystyrene resin and its use in solid phase (peptide) synthesis

2-Aminoethanol was used to successively replace hydrazine in the preparation of aminomethyl polystyrene resin thereby facilitating purification and by-product removal. The syntheses of the polypeptides ACP (65-74) and oxytocin demonstrated that the use of aminomethyl polystyrene resin prepared in this manner was equal to or better than that prepared using the hydrazine method.     

The 2-(diphenylphosphino) ethyl group (DPPE) as a new carboxyl-protecting group in peptide chemistry

The use of the 2-(diphenylphosphino)ethyl group for carboxyl-protection of amino acids or peptides is described. This group is easily introduced by esterification using 2-(diphenylphosphino) ethanol in the presence of dicyclohexylcarbodiimide and 4-(dimethylamino)pyridine. These Dppe esters are stable under the standard conditions for peptide synthesis. Deprotection is carried out under mild conditions by quaternisation using methyl iodide followed by a β-elimination induced by fluoride ion or potassium carbonate.     

Extraction-spectrophotometric determination of trace iron (II) in sea water with 2-[2-(3,5-dibromopyridyl)azo]-5-diethylaminobenzoic acid

An extraction-spectrophotometric method is described for the determination of traces of iron(II) with 2-[2-(3,5-dibromopyridyl)azo]-5-diethyl-aminobenzoic acid. The reagent forms a stable and blue 12 iron/reagent complex that can be extracted into chloroform. The apparent molar absorptivity of the iron(II) complex is 1.09 × 10⁵ 1 mol^–1 cm^–1 at 624 nm in chloroform. The reagent is relatively selective; interferences from cobalt, copper, nickel and vanadium can be removed by using dimethylglyoxime and EDTA. The method is applied to the determination of iron (II) in sea water and aluminium alloys with good precision and accuracy.     

N-[1-(取代苯基)乙基]-2-羟基苯甲酰肼的合成、表征及抑菌活性

依据邻羟基二苯醚及芳香肼类化合物的抗菌特性, 以邻羟苯基为分子核心, 酰肼键为桥基, 设计合成了7种未见报道的N-(取代苯基)乙基-2-羟基苯甲酰肼类化合物. 以水杨酸甲酯为原料, 经肼解反应后与取代苯乙酮缩合, 再与硼氢化钠反应制得目标化合物, 化合物结构经IR, ¹H NMR和元素分析等证实. 抗菌活性测试结果表明, 该类化合物对不同菌株的抑菌活性具有明显的选择性和特异性. 当质量浓度为1×10^-4 g/mL时, 化合物3b和3e对大肠杆菌和白色念珠菌的抑菌率高达100%, 有极强的抑菌活性; 所有化合物对金黄色葡萄球菌的抑菌率均大于70%, 有一定的抑菌活性. 构效关系分析结果表明, 苯基中引入Cl或Br等卤原子能显著增强化合物的抑菌活性, 而引入-NO₂及-CH₃基团则会降低其抑菌活性.     

DIASTEREOSELECTIVE SYNTHESIS AND STEREOCHEMISTRY OF (Z)-1-[3-ARYL-2-(PHENYLSULFANYL)-2-OXIRANYL]-1-ETHANONES

Diastereoselective synthesis of a series of (Z)-1-[3-aryl-2-(phenylsulfanyl)-2-oxiranyl]-1-ethanones was effected from the reaction of (Z)-4-aryl-3-(phenylsulfanyl)-3-buten-2-ones with alkaline hydrogen peroxide in tetrahydrofuran. The stereochemistry of the oxiranes has been deduced from two-dimensional NOESY spectrum.     

六(乙氧基吡咯烷酮)三聚磷腈的合成与表征

以N-羟乙基吡咯烷酮与氢化钠作用生成相应的钠盐,再将此钠盐与六氯三聚磷腈(HCCP)发生亲核取代反应,合成了六(乙氧基吡咯烷酮)三聚磷腈,用IR、31P NMR、1H NMR、13C NMR、DEPT、FABMS等现代谱学技术对其结构进行了表征。生物活性试验表明,此化合物1mg/mL时对腐生线虫Panagrellus redivivus的72h致死率为52·7%。     

二乙二醇丙酸甲酯的合成与结构表征

采用二乙二醇和丙酸甲酯为主要原料,以钾为催化剂,在通N_2气保护的条件下合成二乙二醇丙酸甲酯,用离子排阻高效液相色谱法对合成的二乙二醇丙酸甲酯进行定量分析。最佳合成条件:二乙二醇与丙酸甲酯的物质的量比为1∶2,催化剂的质量为反应物二乙二醇质量的1.5%,于25℃条件下反应24 h,产物经硅胶柱分离、乙酸乙酯梯度洗脱,然后干燥,制得二乙二醇丙酸甲酯成品,收率为61.5%,纯度达99.5%。用FT-IR,~1H–NMR,GC–MS法对二乙二醇丙酸甲酯的分子结构进行了确证。     

1-(2-氰乙基)-2-氧代环戊基甲酸甲酯的选择性水解脱羧

对1-(2-氰乙基)-2-氧代环戊基甲酸甲酯(4)的选择性水解脱羧反应进行了系统研究. 发现上述化合物在碱的催化作用下主要生成开环副产物2-(2-氰乙基)己二酸二甲酯及2-(2-氰乙基)己二酸; 由于氰基在酸性介质中也可发生水解, 因此对1-(2-氰乙基)-2-氧代环戊基甲酸甲酯在酸性情况下水解脱羧的反应条件进行了探索, 发现在4 mol•L－1盐酸介质中, 50 ℃下反应24 h, 以84.0%的收率得到目标产物3-(2-氧代环戊基)-丙腈.     

Synthesis and Crystal Structure of 1-（4-Fluorophenyl）-2-hexylthiobenzo[4,5]-furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5（1H）-one

The crystal structure of the title compound 1-(4-fluorophenyl) -2-hexylthio-benzo [4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H) -one(C23H21FN4O2S,Mr = 436.5) has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic,space group P21/n with a = 13.9854(3) ,b = 17.2678(4) ,c = 18.1828(5) ,β = 99.364(2) °,V = 4332.58(18) 3,Z = 4,Dc = 1.338,F(000) =1824,μ = 0.185 mm-1,MoKa radiation(λ = 0.71073) ,R = 0.0538 and wR = 0.1162 for 4728 observed reflections with I > 2σ(I) . X-ray diffraction analysis reveals the fused rings of benzo[4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a] pyrimidin-5(1H) -one system are nearly coplanar. The crystal packing is mainly stabilized by weak intermolecular C-H···O hydrogen bond and π-π interactions.     

(1R,3S,4S)-2-苄氧羰基-2-氮杂双环[2.2.1]庚烷-3-羧酸的合成

以(R)-(+)-α-甲基苄胺为原料,依次经缩合,Diels-Alder反应,还原,Cbz-保护和水解反应,合成了抗丙肝新药HCV NS3/4A蛋白酶拟肽类抑制剂的重要中间体——(1R,3S,4S)-2-苄氧羰基-2-氮杂双环[2.2.1]庚烷-3-羧酸,总收率66%,其结构经1H NMR和ESI-MS确证。     

2,5-二[4-(2-芳基乙烯基)苯基]噁二唑的合成及发光特征

二乙烯联苯及其衍生物是一种可发射蓝光的小分子空穴型有机发光材料, 通过Wittig-Horner反应, 将电子传输型噁二唑环“嵌入”其中, 设计合成了6个2,5-二[4-(2-芳基乙烯基)苯基]-1,3,4-噁二唑化合物. 经光谱分析和元素分析等方法确认了它们的化学结构. IR和UV-vis分析数据表明标题化合物分子结构中的C＝C双键均为反式结构特征. 研究结果表明: 2,5-二[4-(2-对二甲氨基苯基乙烯基)苯基]-1,3,4-噁二唑具有良好的蓝色发光性能; 取代基对标题化合物的UV-vis吸收光谱和发光特性的影响显着.