Synthese von substituierten 5-Amino-1,2,4-triazolen

Synthesis of Substituted 5-Amino-1,2,4-triazoles N-Nitro-amidino-dithiocarbimidic acid dimethylester 1 reacts with monosubstituted hydrazines under formation of the substituted 5-amino-1, 2, 4-triazoles. Disubstituted hydrazines give under the same conditions N-nitro-amidino-S-methyl-isothiosemicarbazides. The reaction of some more hydrazine derivatives with 1 yields the adequate substituted 1, 2, 4-triazoles.     

Eine neue Synthese substituierter 4-Amino-1,3-thiazole

A New Synthesis of Substituted 4-Amino-1, 3-thiazoles In the 5-position substituted 4-amino-2-alkylthio-1, 3-thiazoles are prepared in good yields from N-nitro-amidino-dithiocarbamates 1 and α-halogen-carbonylcompounds or chloracetonitrile. 1 reacts with 1, 3-dichlor-acetone under formation of adequate bis(1, 3-thiazolyl)ketones. According to the same principle the reaction of the dipotassium salt of the N-nitro-amidino-dithiocarbimidic acid 7 with two equivalents of the α-halogen-carbonylcompound yields 4-amino-5-benzoyl-2-(benzoyl-methylthio)-1, 3-thiazoles.     

Synthese von 3-Amino-1.2-dithioliumsalzen und deren Umwandlung in 2-Nitro-3-amino-thiophene

Synthesis of 3-Amino-1,2-dithiolium Salts and their Conversion to 2-Nitro-3-aminothiophenes 3-Amino-1.2-dithiolium salts 2a–1 are easily available from 3-chloro-1,2-dithiolium salts 1 and secondary amines. A new procedure to prepare 2-nitro-3-aminothiophenes 3 starting from N,N-substituted 3-amino-5-phenyl-1,2-dithiolium salts 2 is described which consists in a nucleophilic exchange of a sulfur atom for the carbon atom of nitromethane. The structure of 3 has been confirmed by reductive cyclization and by spectroscopic methods.     

Synthese von 4-Arylazo-isoxazoliumsalzen

Synthesis of 4-Arylazo-isoxazolium Salts 4-Arylazo-isoxazolium salts ( 3, 4 ), a new class of cationic dyes, are now available by alkylating the isoxazoles 5 and by reacting 1,3-dicarbonyl compounds of the type 1 with N-alkyl-hydroxylamines, respectively. In contrast to the isothiazole system the alkylation of isoxazoles 5 at the ring nitrogen atom does not cause a significant bathochromic shift. 4-Arylazo-5-methoxy-isoxazolium salts ( 8 ) can be prepared by alkylating 4-arylazo-isoxazolin-5-ones ( 6 or 11 ) with dimethyl sulfate. The analogous reaction with 4-arylazo-5-alkylthio-isoxazolines ( 12, 13 ) failed, however, the expected 4-arylazo-5-alkylthio-isoxazolium salts (e. g. 14 ) can be obtained from 12 and trialkyloxonium fluoborate.     

Synthese von 4-Alkoxy-2-hydroxyphenylketoximen als Metallextraktions-Reagenzien

Synthesis of 4-Alkoxy-2-hydroxyphenyl Ketoximes as Reagents for Metal Extraction The C-Acylation (Friedel-Crafts reaction) of resorcinol with aluminium chloride, the monoetherification in 4-position of the resulting 2,4-dihydroxyphenylketones, and the preparation of oximes ( 8, 9, 10, 11 ) from this ketones were investigated. The compounds obtained are characterized by elemental analysis, and the i.r., u.v. and ¹H-n.m.r. spectra are discussed. Solubility data of some oximes are determined in water, octane and toluene. The extraction properties for copper-(II)-and iron-(III)-ions are measured by isotope methods in relation to the extragent structure, the extraction time and the pH-range.     

2-氨基-4-甲氧基-6-甲基-1,3,5-均三嗪的高效液相色谱测定

利用反相高效液相色谱外标法测定了2-氨基-4-甲氧基-6-甲基-1，3，5-均三嗪的含量。方法的标准偏差为0.35，变异系数为0.37%，平均回收率99.78%。     

5-甲基-2-氨基-1,3,4-噻二唑的合成

本文报道了用硫代氨基脲与乙酸在盐酸、磷酸、多聚磷酸、硫酸等催化下,合成5-甲基-2-氨基-1,3,4-噻二唑,并对工艺条件进行了试验,结果表明,最佳工艺条件为硫代氨基脲与乙酸的摩尔比为1:14,浓盐酸催化,回流3小时,产率为74.34％。     

Untersuchungen zur regioselektiven Halogenierung von 4-Amino-2-iodmethyl-6-methyl-pyrimidinen

Studies on the Regioselective Halogenation of 4-Amino-2-iodomethyl-6-methylpyrimidines In the presence of oxidants, 4-amino-2-iodomethyl-6-methylpyrimidines 2 undergo regioselective reactions in the positions 2 and/or 5. Thus, the reaction of 2a with hydrogen peroxide proceeds under dealkylation and iodination to give 4-amino-5-iodo-6-methylpyrimidine 7 . Depending on reaction temperature and molar ratios the reaction of 2a with bromine or chlorine leads to the corresponding 4-amino-5-halogeno-2-halogenomethyl-6-methyl-pyrimidines 2c, 9a and 9d . The 5-substituted pyrimidines 2b, c afford the 2-bromo (or chloro) methyl derivatives 9b, c .     

1-甲基-3-正丙基-4-氨基-5-吡唑羧酰胺的制备

1 甲基 3 正丙基 5 吡唑羧酸经硝酸 -浓硫酸硝化制得 1 甲基 3 正丙基 4 硝基 5 吡唑羧酸 ,收率 85 %;用氯化亚砜将其酰氯化制得 1 甲基 3 正丙基 4 硝基 5 吡唑羧酰氯 ,该吡唑羧酰氯与浓氨水反应制得 1 甲基 3 正丙基 4 硝基 5 吡唑羧酰胺 ,收率 90 %;硝基吡唑羧酰胺在乙醇中用氯化亚锡还原制得 1 甲基 3 正丙基 4 氨基 5 吡唑羧酰胺 ,收率 84%。研究了反应的较佳合成工艺条件 ,产品经TLC、IR及MS谱进行了结构表征。     

5-甲基-2-苯基-1,2,3-三唑-4-甲酸的合成及表征

以苯胺和乙酰乙酸乙酯为原料,经过重氮化和偶联反应得到2-(2-苯腙基)-3-氧代丁酸乙酯,再在铜-空气作用下与醋酸铵缩合/氧化合环反应,得到5-甲基-2-苯基-1,2,3-三唑-4-甲酸乙酯,后经水解得到5-甲基-2-苯基-1,2,3-三唑-4-甲酸。该合成方法高效便捷。     

4-氨基-1-甲基-3-正丙基吡唑-5-甲酰胺合成工艺研究

以 3 正丙基吡唑 5 羧酸乙酯为起始原料 ,经多步反应合成了 4 氨基 1 甲基 3 正丙基吡唑 5 甲酰胺 ,并对工艺进行了如下改进 :(1)将甲基化、水解两步反应合并为“一勺烩”工艺 ,中间产物不需硅胶柱分离、提纯 ,直接进行水解 ;(2 )硝化后处理增加了溶媒提取工序 ;(3)还原反应采用催化还原法 ,以价廉的甲酸铵代替氯化亚硒作还原剂。总收率达到 39 3% ,较原工艺提高了8 5 % ,具有操作简单 ,反应条件温和 ,宜于工业化生产 ,为合成 4 氨基 1 甲基 3 正丙基吡唑 5 甲酰胺提供了一个较好的方法。     

Synthese von Moosinhaltsstoffen. 8. Sphagnumsäure und ihre Abbauprodukte

Syntheses of Bryophyte Constituents. 8. Sphagnum Acid and its Degradation Products For Sphagnum acid ( 1 ) and its enzymatic degradation product 5-hydroxy-4-(4-hydroxyphenyl)-5H-furan-2-on ( 2 ) efficient syntheses on preparative scale were developed. For the (4-hydroxyphenyl)butenolide 2 some characteristic chemical transformations are observed in acidic and basic medium.     

Prostaglandine und Prostaglandinvorstufen. Untersuchungen zur Synthese von 8-Methylprostansäurederivaten

Prostaglandins and Prostaglandin Intermediates. Synthetic Approach to 8-Methyl Prostanoic Acid Derivatives Starting from the chiral key-product 1 the 8-methyl prostanoic acid derivative 13 was prepared within 10 steps. Construction of the α-side chain involves DIBAH-reduction of the lacton moiety of 1 followed by Wittig-olefination with a C₅-ylide. C₁-Homologation of the oxo group of 1 via cyanhydrin synthesis and Wittig-olefination with a C₇-ylide are important steps to form the ß-side chain of compound 13 .