3-氨基-4-腈基吡唑的合成

经两步反应全盛了3－氨基－4－腈基吡唑；丙二腈与原甲酸三乙酯反应得到乙氧亚甲基丙二腈；其产物再与水合肼反应得到3－氨基－4－腈基吡唑，总收率为68．3％。     

One-pot synthesis of 3-amino-4-aryl- and 3-amino-4-hetarylfurazans

A “one pot” method for the synthesis of 3-amino-4-aryl- and 3-amino-4-hetarylfurazans from β-aryl- and 4-β-hetaryl-β-oxo acid esters was developed. Dedicated to Corresponding Member of the Russian Academy of Sciences E. P. Serebryakov on the occasion of his 70th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 1030–1032, April, 2005.     

Parallel synthesis of 3-amino-4H-quinolizin-4-ones, fused 3-amino-4H-pyrimidin-4-ones, and fused 3-amino-2H-pyran-2-ones

On the basis of the enaminone methodology, libraries of 3-amino-4H-quinolizin-4-ones, fused 3-amino-4H-pyrimidin-4-ones, and fused 3-amino-2H-pyran-2-ones were synthesized by the solid-phase and by the solution-phase parallel synthesis. The solution-phase approach turned out to be advantageous over the solid-phase approach. The solution-phase synthesis afforded, in most cases, analytically pure products in high yields, whereas the solid-phase approach gave products in poor yields and in low purity.     

Amine electrosynthesis from 1-ethyl-4-nitro-3-cyanopyrazole

Polarography and preparative electrolysis are used to show that the electrochemical behavior of 1-ethyl-4-nitro-3-cyanopyrazole (1) in acidic aqueous-alcoholic solutions resembles the behavior of nitrobenzene. By varying the parameters of the electroreduction (ER) of compound 1, one can obtain either 1-ethyl-4-amino-3-cyanopyrazole (2) or 1-ethyl-4-amino-3-cyano-5-chloropyrazole (3). Compound 2 is formed during the ER of compound 1 in the presence of a mediator (titanium(III)) at temperatures below 10°C. Compound 3 is produced by the direct reduction of compound 1 on a lead electrode (30% ethanol, 10% HCl). The yield of amine chlorohydrates 2 and 3 is 56 and 92%, respectively. The mediated ER of compound 1 at catholite temperatures higher than 10°C yields a mixture of compounds 2 and 3; the proportion of the latter increases with temperature to become the major product at 60°C. Compound 3 is formed due to the rearrangement of the hydroxylamine derivative produced by the ER of compound 1, followed by the substitution of chlorine for the hydroxy group.     

Synthesis and Crystal Structure of 1-（2,6-Dichloro-4-nitrophenyl）-5-amino-4-cyanopyrazole

The crystal structure of 1-（2,6-dichloro-4-nitrophenyl）-5-amino-4-cyanopyrazole （C10H10Cl2N5O2, Mr = 298.09） has been determined by single-crystal X-ray diffraction. It crystallizes in the triclinic system, space group P1^- with a = 8.1258（10）, b = 8.6460（10）, c = 10.0214（12） A, α = 68.986（2）, β = 71.598（2）, γ = 85.181（2）°, V = 623.26（13） A3, Z = 2, Dc = 1.588 g/cm^3,μ = 0.525 mm^-1, F（000） = 300, R = 0.0613 and wR = 0.1524 for 1890 observed reflections, and the extinction coefficient = 0.010（5）. The crystal structure is stabilized by N-H...N hydrogen bonds.     

Stereospecific synthesis of cis- and trans-4-amino-3-hydroxythiophanes

The reduction of 4-benzoylamino- and 4-carbethoxyamino-3-ketothiophanes proceeds stereospecifically to form only trans-4-benzoylamino- and trans-4-carbethoxyamino-3-hydroxythiophanes, respectively, from which trans-4-amino-3-hydroxythiophane is obtained by alkaline hydrolysis. It was established that acid hydrolysis of trans-4-carbethoxyamino-3-hydroxythiophane leads only to trans-4-amino-3-hydroxythiophane, while acid hydrolysis of trans-4-benzoylamino-3-hydroxythiophane is accompanied by inversion to form cis-4-amino-3-hydroxythiophane. Derivatives of the cis- and trans-isomeric pairs of 4-amino-3-hydroxythiophanes were synthesized.Translated from Khimiya Geterotsilicheskikh Soedinenii, No. 12, pp. 1609–1613, December, 1970.     

Asymmetric synthesis of 3-amino-2-hydroxy-4-phenylbutanoate

Asymmetric synthesis of 3-amino-2-hydroxy-4-phenylbutanoate, a key component of the natural product bestatin and HIV protease inhibitors of KNI-272 and R-87366, has been achieved from the stereoselective aldimine coupling reaction between 3-phenyl-2-aminopropanenitrile and (Z)-α-methoxy trimethylsilyl ketene acetal in the presence of Lewis acids.     

3-苄基-4-氨基-5-芳胺基-1,2,4-三唑的合成与表征

酰氨基硫脲是一类重要的有机合成中间体[1-3]。其最终产物大都有消炎、镇痛、抗菌、杀虫、除草、调节植物生长等生理活性。本文以苯乙酸乙酯与芳胺为基本原料,经多步反应,制得1 苯乙酰基 4 芳基氨基硫脲,研究了它们在水合肼存在下的关环反应,合成了3 苄基 4 氨基 5 芳胺基 1,2,4 三唑,其结构经元素分析、红外光谱、核磁共振氢谱、碳谱表征。1　实验部分1 1　仪器与试剂ＸＴ4Ａ型显微熔点仪(温度计未校正);ＣＥ公司(意大利)Ｆｌａｓｈ1112型自动元素分析仪;Ｂｒｕｋｅｒ公司(德国)Ｅｑｕｉｎｏｘ55型红外分光光度计,ＫＢｒ压片;Ｂｒｕｋ…     

An investigation of the synthesis of 3-amino-4-ethoxycarbonylaminotetrahydrothiophene

Methods of synthesis of 3-amino-4-ethoxycarbonylaminotetrahydrothiophene (VIII), and of other diamines, from 4-ethoxycarbonylaminotetrahydro-3-hydroxyiminothiophene (I), 2-benzylidene-4-ethoxycarbonylaminotetrahydro-3-hydroxyiminothiophene (III) and 4-ethoxycarbonylaminotetrahydro-3-hydroxythiophene (V) were investigated. Chlorination of V followed by the Gabriel synthesis gave VIII.     

The synthesis of 2-amino-4-tert alkylphenols

Summary The reduction of 2-nitro-4-tert-alkylphenols with sodium sulfide is described.     

An investigation of the synthesis of 3-amino-4-ethoxycarbonylaminotetrahydrothiophene

Methods of synthesis of 3-amino-4-ethoxycarbonylaminotetrahydrothiophene (VIII), and of other diamines, from 4-ethoxycarbonylaminotetrahydro-3-hydroxyiminothiophene (I), 2-benzylidene-4-ethoxycarbonylaminotetrahydro-3-hydroxyiminothiophene (III) and 4-ethoxycarbonylaminotetrahydro-3-hydroxythiophene (V) were investigated. Chlorination of V followed by the Gabriel synthesis gave VIII.     

A concise synthesis of 2-chloro-3-amino-4-methylpyridine

An improved and commercially valuable process is developed for the scalable synthesis of 2-chloro-3-amino-4-methylpyridine (CAPIC), a key intermediate of Nevirapine. The synthesis was accomplished in four steps, featuring condensation starting from 4,4-dimethoxyl-2-butanone and cyanoacetamide with ammonium acetate and acetic acid as catalysts. The total yield of the process is 62.1%. The pure CAPIC sample was confirmed with FTIR, ¹H NMR, and ¹³C NMR spectra.     

Potassium phthalimide promoted green multicomponent tandem synthesis of 2-amino-4H-chromenes and 6-amino-4H-pyran-3-carboxylates

A one-pot efficient, green, practical, and environmentally friendly multicomponent synthesis of 5-oxo-4-aryl-5,6,7,8-tetrahydro-4H-chromenes, ethyl-6-amino-4-aryl-5-cyano-2-methyl-4H-pyran-3-carboxylates as well as 2-amino-4-aryl-7-hydroxy-4H-chromene-3-carbonitriles via tandem the Knoevenagel-cyclocondensation has been described in the presence of a green, low-cost, mild, efficient, and commercially available potassium phthalimide as the organocatalyst. This technique is a safe and ecofriendly approach to the synthesis of different 4H-chromens and 4H-pyrans that offers many merits including short reaction times, high yields, straightforward work-up, and no use of hazardous organic solvents.     

4-alkoxy- and 4-amino-2,2'-bipyrrole synthesis

[Structure: see text] 4-alkoxy-2,2'-bipyrroles and the first examples of 4-amino-2,2'-bipyrroles have been synthesized by a diversity-oriented strategy from 4-hydroxyproline. The bipyrrole products offer interesting potential as building blocks for making pyrrole products, as demonstrated by the first synthesis of an amino prodigiosin analogue.     

Unexpected synthesis of 6-amino-2,3-dihydro-4-pyrone-3-spirocyclohexane

The reaction of 2-amino-2-(trichloromethyl)tetrahydro-4-pyrone-5-spirocyclohexane with ethylenediamine afforded 6-amino-2,3-dihydro-4-pyrone-3-spirocyclohexane, whereas 2-amino-5,5-dimethyl-2-(trichloromethyl)tetrahydro-4-pyrone gave 2-(3-hydroxy-2,2-dimethylpropionylmethylene)imidazolidine in low yield.     

The synthesis of 2-amino-4-aryl-3-ethoxycarbonyl-4H-naphtho[1,2-b]pyrans revisited

An expeditious and unequivocal synthesis of some 2-amino-4-aryl-3-ethoxycarbonyl-4H-naphtho-[1,2-b]pyrans 3 is reported. Previous papers describing the preparation of this type of compound have been amended and a convenient and direct procedure for its preparation is now presented.     

Stereospecific synthesis of new 4-amino-1,2,3-cyclohexanetricarboxylic acids and 4-amino-1,3-cyclohexanedicarboxylic acids

Diels-Alder adducts of 1,2-dihydropyridine with maleic and acrylic acid derivatives were stereospecifically converted by way of RuO4 oxidation into new 4-amino-1,2,3-cyclohexanetricarboxylic acids and 4-amino-1,3-cyclohexanedicarboxylic acids.     

A novel approach to the synthesis of amino-sugars. Routes to selectively protected 3-amino-3-deoxy-aldopentoses based on pyridinium salt photochemistry

A new approach for the synthesis of selectively blocked 3-amino-3-deoxyaldopentoses is presented. The strategy is based on employment of a pyridinium salt photocyclization-aziridine ring-opening sequence to prepare stereochemically defined, enantiomerically enriched aminocyclopentendiol derivatives. Ring-opening reactions transform these substances into terminally differentiated aminopolyols, which serve as precursors to the target amino-aldopentoses. The utility of this strategy is demonstrated by its application to the syntheses of protected derivatives of D- and L-3-amino-3-deoxyxylose, L-3-amino-3-deoxyarabinose, and a late-stage intermediate in a potential route to N-acetylneuraminic acid.     

The synthesis of 3-amino-5-arylisothiazoles from propynenitriles

A new synthesis of 3-amino-5-arylisothiazoles is reported. The reaction is operationally simple, utilises readily synthesised propynenitriles as starting materials and is tolerant of a range of functional groups. The optimised reaction conditions can also be used with 3-chloropropenenitriles in place of propynenitriles.