Ferrocene Derivatives of Valine and Leucine

Methyl and ethyl esters of valine and leucine were reacted with ferrocenecarbaldehyde to obtain azomethines (C₅H₅)Fe(C₅H₄CH=NCHRCOOR′) whose reactions with sodium borohydride provide ferrocenylmethyl derivatives (C₅H₅)Fe(C₅H₄CH₂NHCHR⋅COOR′) [R=(CH₃)₂CH, (CH₃)₂CHCH₂; R′ = CH₃, C₂H₅]. The latter compounds react with sodium hydroxide to give, after treatment of the reaction mixtures with acetic acid, N-substituted amino acids (C₅H₅)Fe(C₅H₄CH₂NHCHRCOOH).__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 6, 2005, pp. 1046–1048.Original Russian Text Copyright © 2005 by Popova, Yurashevich, Cherevin, Gulevich, Reshetova, Knizhnikov.     

N-Benzyl Derivatives of Leucine Esters

Leucine methyl and ethyl esters reacted with 3-bromobenzaldehyde and 4-chlorobenzaldehyde in anhydrous methanol in the presence of magnesium sulfate to afford the coresponding Schiff bases of the general formula (CH3)2CHCH2CH(COOR¹)N=CHR² [R¹ = CH3, C2H5, R²= 3-BrC6H4, 4-ClC6H4]. Their reduction with sodium tetrahydridoborate yielded N-benzyl derivatives (CH3)2CHCH2CH(COOR¹)NHCH2R², which were converted into N-acyl-N-benzyl derivatives (CH3)2CHCH2CH(COOR¹)N(COR³)CH2R²[R³= CH₃, C₆H₅].     

Alkylation of Pyrimidine Derivatives with Chloroacetic Acid Esters

Alkylation of 6-methyluracil, 5-hydroxy-6-methyluracil, and 6-methyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-5-ylammonium sulfate with isopropyl and ethyl chloroacetates afforded previously unknown alkyl 2-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-1-yl)acetates, alkyl 2-(1-alkoxycarbonylmethyl-6-methyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-3-yl)acetates, 1,3-bis(alkoxycarbonylmethyl)-6-methyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-5-ylammonium sulfates, and alkyl 2-[1,3-bis(alkoxycarbonylmethyl)-6-methyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-5-yloxy]acetates.     

含羟基芳基或氨基芳基的磷酰胺酯衍生物的合成

采用均相反应的方法合成了6个含羟基芳基或氨基芳基的磷酰胺酯衍生物:[(ClCH_2CH_2)_2NP(O)(OPh)(XArY)](X:O,NH;Y:m或p-OH或NH_2).用元素分析、红外光谱、氢核磁共振谱及质谱证实了它们的组成及结构.     

N-苯基硫代膦酰基氨基酸及氨基乙酸乙酯衍生物的研究

本文报告了42个新的N-苯基硫代膦酰基氨基酸及氨基乙酸乙酯衍生物的制备;改进了N-膦酰基氨基酸酯衍生物的制备方法;对衍生物的生物活性以及某些衍生物在酸碱水溶液中的稳定性进行了初步探讨。     

二氧化钛纳米粒子催化合成Hantzsch酯和多氢喹啉衍生物(英文)

1,4-Dihydropyridine and polyhydroquinoline derivatives have been prepared efficiently in a one-pot synthesis via Hantzsch condensation using nanosized titanium dioxide as a heterogeneous catalyst.The present methodology offers several advantages such as excellent yields,short reaction times (30-120 min),environmentally benign,and mild reaction conditions.The catalyst can be readily separated from the reaction products and recovered in excellent purity for direct reuse.     

Vanillin Esters of Aliphatic Acids in the Synthesis of 4,7-Phenanthroline Derivatives

Condensation of vanillin esters of aliphatic acids with 6-aminoquinoline and cyclic c-diketones (1,3-cyclohexanedione and dimedone) afforded new 2-methoxy-4-(11-oxo-7,8,9,10,11,12-hexahydrobenzo[b][4,7]phenanthrolin-12-yl)phenyl esters of carboxylic acids.     

二元酸茄尼醇烷基5-氟尿嘧啶二酯衍生物的合成及其抗肿瘤活性研究

以茄尼醇为原料与4种不同的酸酐反应,然后再与N-烷羟基-替加氟反应,得到12个新的目标化合物.其结构经IR,1H NMR,MS确认.初步的体外抗肿瘤实验结果表明,目标化合物具有一定抗肿瘤活性.     

A Mild Method for the Formation of Tosylhydrazone Derivatives from Keto Esters

An improved preparation of tosylhydrazones of α- and β-keto esters, by means of active aluminium oxide as catalyst, are described.     

Derivatives of Some 2-Chloroethylphosphonic Acid Esters,with Plant Growth Regulating Activity

Abstract

A method for the synthesis of esters of 2-(dimethylsulfonium)ethylphos-phonic acid and the results of some trials showing the plant growth regulating activity of these compounds are presented. For the synthesis of the mentioned compounds, dimethyl sulphide is reacted with 2-chloroethylphosphonic acid esters; these esters are obtained through the complex[1] of AlCl₃, PCl₃ and 1,2-dichloroethan (1). Using the optimum reaction conditions, very good yields were obtained (96–99%). This complex is reacted with different alcohols to give 2-chloroethylphosphonic acid esters (2) (R?Me, Et, Pr, i-Pr, Bu, i-Bu, Pe). Using the optimum reaction conditions, in the case of methanol the maximum obtained yield was 50%. In the case of the other alcohols, the obtained yields were between 76 and 83%. An exception is i-propanol. whose ester was obtained with low yields and the reaction parameters modification have little influence on the yield. The reaction of the esters with dimethyl sulphide gives, in good yields (between 69 and 79%). esters of 2-(dimethylsulfonium)ethylphosphonic acid (3). substances with plant growth regulating activity.     

Chiral Resolution of Benzophenone Imine Derivatives of Amino Acid Esters on Chiral Stationary Phases

Abstract

A convenient way of resolving the enantiomers of amino acid esters after their derivatization using benzophenone imine is described. The enantiomers of benzophenone Schiff base derivatives of various amino acid ethyl esters are readily separated on three commercially available chiral stationary phases (CSPs). Among them, CSPs 2 and 3 afford generally the base-line enantioresolution for the analytes studied. From understanding of chromatographic results, a plausible chiral recognition mechanism is discussed.     

Tetralone Esters as Intermediates for the Synthesis of Podophyllotoxin Derivatives Via Cyclopropanation of Chalcones

Cyclopropyl ester (8a-f) were synthesized by the cyclopropanation of chalcones (7a-e) in dry benzene using powdered sodium in 80-85% yield. Preparation of tetralone ester (4a-e), an intermediate for the synthesis of podophyllotoxin derivatives by Lewis acid (SnCl₄) catalyzed cyclization of (8a-e) is also described here.     

Direct Enantiomer Separation of 2-Phenylcyclopropanecarboxylate Esters on Cyclodextrin Derivatives Stationary Phases in GC

IntroductionThechiralcyclopropanesubunitisfoundinawiderangeofnaturalandunnaturalproductspossessingimportalbiologicalpropeFties.Recefltly,manyeffortshavebeenfocusedonthedevelopmentofstereoselectivemethodstofacilitateaccesstoenantioenrichedcyclopropanes.Asthepro-drugsanddrugintermediates,2-phenylcycIopropanecarboxyIatesarethefrsquentlyreportedproductsofenantiosealectivecyclopropanationofolefinsl'2.However,sofar,enantiomericexcessofthesechiralcompoundswasusuallydeterminedbyconvertingtotheLlmen…     

氨基酸5-氟尿嘧啶酯类衍生物的合成及其抗肿瘤活性研究

以N-保护的氨基酸钾盐与1-(ω-溴丙基)-5-氟尿嘧啶和1-(ω-溴丁基)-5-氟尿嘧啶反应,制备了18种氨基酸的ω-(N¹-5-氟尿嘧啶基)-丙醇酯和丁醇酯的盐酸盐,并确定了它们的结构。动物试验的初步结果表明,酪氨酸、苯丙氨酸的3-(N¹-5-氟尿嘧啶基)-丙醇酯盐酸盐对小鼠艾氏腹水癌的抑制率分别为88.1%和86.7%。     

缬氨酸消旋新工艺

缬氨酸消旋新工艺;缬氨酸;二苯甲酰L-酒石酸;消旋     

Synthesis of Fused Quinolizine Derivatives by Condensation of Cyclic Schiff Bases with β-Keto Esters

A new procedure has been developed for the synthesis of fused nitrogen-containing heterocycles having a bridgehead nitrogen atom via condensation of cyclic Schiff bases with β-keto esters.