Aminonucleosides. IV. (3-Amino-3-desoxyerythrofuranosyl)-9-adenine

The synthesis of 9-(3-amino-3-deoxy-β-L-(and D)-erythrofuranosyl)-adenine is described. This compound is a close analog of the aminonucleoside of puromycin.     

Manganese(II) complexes with 3,5-diphynylisoxazole, 3-amino-5-methylisoxazole and 5-amino-3,4-dimethylisoxazole

Summary The complexes of manganese(II) halide and thiocyanate with 3.5-diphenylisoxazole (3,5-diPhisox), 3-amino-5-methyl-isoxazole(3-AMI) and 5-amino-3,4-dimethylisoxazole (5-ADI) have been prepeared and characterized by spectrocopic and magnetic methods and by conductivity measurements. The 3,5-diPhisox ligand is N-bonded, while the isoxazolamine ligands are bridging N(ring)- and O-bonded. All the compounds are nonelectrolytes, high-spin, with an octahedral stereochemistry.     

Microwave-assisted synthesis of 4-amino-3,5-dihalopyridines

4-Amino-3,5-dihalopyridines have been efficiently prepared via microwave-assisted nucleophilic aromatic substitution of 3,4,5-trihalopyridines using 1-1.1 equiv of primary and secondary amines. The reaction is also applicable to electron rich arylamines.     

Synthesis of Derivatives of 3,5-Dioxopyrazolidine

The reaction of monohydrazides of 2-R-4-methylcyclohex-4-ene-1,1-dicarboxylic acids with ethoxymethylenemalonic acid diethyl ester leads to N-(2,2-diethoxycarbonylethylenyl)hydrazides of 2-R-4-methylcyclohex-4-ene-1,1-dicarboxylic acids, which are acylated by the anhydrides of trifluoroacetic and acetic acids with the formation of derivatives of 3,5-dioxopyrazolidine and 5-oxopyrazoline respectively.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 216–220, February, 2005.     

Molecular and crystal structure of 1-amino-3,5-diphenyl-2,4,4,6,6-Pentacyano-cyclohex-1-ene and 1-amino-3,5-diphenyl-2,4,4,6-tetracyanocyclohex-1-ene

Molecular and crystal structures of 1-amino-3,5-diphenyl-2,4,4,6,6-pentacyano-cyclohex-1-ene (I) and 1-amino-3,5-diphenyl-2,4,4,6-tetracyanocyclohex-1-ene (II) are studied to examine intermolecular interactions. Crystal data for (I): space group P2₁, a=11.172(3), b=6.561(2), c=16.390(4) Å, β=100.25(2)⁰, V=1182.1 ų, Z=2, R=0.046; for (II): space group P1, a=10.756(3), b=10.890(3), c=12.999(3) Å, α=62.20(2), β=70.73(2), γ=65.42(2)⁰, V=1207.2 ų, Z=2, R=0.074. Intermolecular bonds via the aminonitrile fragment in (I) lead to formation of chains along they axis: N1…N6′ (1?x, ?1/2+y, 1?z) of 3.465(8) Å, N6…N1″ (1?x, 1/2+y, 1?z), and the contact with the solvent (acetone) O1…N1 of 2.984(7) Å. In compound (II), the intermolecular contacts N1…N5′ (?x+1, ?y, ?z+1) of 3.064(7) Å link the molecules into dimeric associates.     

Studies on pyrazines, 8. An improved syntheses of 2-amino-3,5-dibromo- and 2-amino-5-bromopyrazines

The titled dibromopyrazine ( 2 ) was prepared in 54% yield by the modified procedure for bromination of 2-aminopyrazine ( 1 ) using bromine and pyridine in chloroform solution. Similarly, 2-amino-5-bromopyrazine ( 3 ) was directly prepared in 36% yield by bromination using 1.2 equivalents of the above reagents.     

Synthesis of heterocyclic compounds. XIII. 2-amino-3-benzyl-3,5-dieyano-6-methoxy-4-phenyl-3,4-dihydropyridines

A synthesis of 2-amino-3-benzyl-3,5-dicyano-6-methoxy-4-phenyl-3,4-dihydropyridines from benzylmalononitriles and benzylidenemalononitrile is described. The structures of the new compounds have been elucidated on the basis of spectral data (ir, nmr, ms), and in two cases (Vb and Ve) by chemical degradation.     

Cyanoethylation of 4-amino-1,2,4-triazolidine-3,5-dithione

The cyanoethylation of 4-amino-1,2,4-triazolidine-3,5-dithione was studied. One cyanoethyl group adds to the nitrogen atom, while the other adds to the sulfur atom of the thioamide groupings. The mechanism of the reaction, which was confirmed by quantum-chemical calculations, was examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 562–564, April, 1973.     

Chemistry of Diamantane Part II. Synthesis of 3,5-Disubstituted Derivatives

Although chemical¹ and microbiological² methods for functionalisation of one or more of the bridgehead positions of diamantane are available, there have been no reports of substitution reactions at the methylene positions apart from that of the preparation of diamantanone (1)¹ by sulphuric acid oxidation of the hydrocarbon. There are three structural arrangements possible for a non-bridgehead disubstituted diamantane, but the synthetic route described here leads exclusively to 3,5-disubstituted derivatives.

When treated with sodium azide in cold methanesulphonic acid diamantanone (1) underwent a Schmidt fragmentation-recyclisation reaction of the type described by Sasaki et al.,³ yielding a compound which was not isolated but which was presumed to be the keto-mesylate (2) since treatment of the reaction mixture with sodium hydroxide caused a second fragmentation and the final product was the unsaturated acid (3) in 41% yield. The structure of the acid is based on the spectral data and on subsequent chemical transformations. The normal Schmidt rearrangement product, which is probably a mixture of the two possibilities (4) and (5), was also isolated in 50% yield. The unsaturated acid was readily recyclised under acidic conditions. Use of 96% sulphuric acid resulted in the formation of the lactone (6), but use of hot 50% sulphuric acid furnished 5ax-hydroxydiamantan-5-one (7) as the preponderant product (82%). That the hydroxyl-group occupied the axial config-     

4-alkyl-6-amino-4-N 3,N 5-diaryl-2-thioxo-1,2,3,4-tetrahydropyridine-3,5-dicarboxamides: I. Tandem synthesis and alkylation. Molecular and crystal structure of 6-allylsulfanyl-2-amino-4-isobutyl-N 3,N 5-di-m-tolyl-3,4-dihydropyridine-3,5-dicarboxamide

4-Alkyl-6-amino-4-N ³,N ⁵-diaryl-2-thioxo-1,2,3,4-tetrahydropyridine-3,5-dicarboxamides were obtained via tandem synthesis involving the Knoevenagel reaction, Michael reaction and intramolecular condensation. Alkylation of the obtained dicarboxamides proceeds regioselectively at the S atom to form the corresponding thioethers. Structure of 6-allylsulfanyl-2-amino-4-isobutyl-N ³,N ⁵-di-m-tolyl-3,4-dihydropyridine-3,5-dicarboxamide was uniquely determined by XRD analysis.     

The reformatsky reaction of 1-acyl-3,5-dimethylpyrazoles. A convenient preparation of 4-amino-3-oxoalkanoic acid derivatives

The conversion of N-acylpyrazoles into β-keto esters was accomplished efficiently by the treatment with α-bromo esters and zinc dust. Using this Reformatsky reaction of N-acylpyrazoles, 4-(protected amino)-3-oxoalkanoic acid derivatives were conveniently prepared as the key intermediates in the synthesis of statines.     

Reactivity of 3,5-bis-(4-amino-1,2,5-oxadiazol-3-yl)-1,2,4-triazole

Alkylation of 3,5-bis(4-amino-1,2,5-oxadiazol-3-yl)-1,2,4-triazole with haloalkanes afforded N-CH₂R derivatives, and nitration furnished the corresponding bis-N-nitramine isolated as a trisodium salt. Treatment of the latter with CH₃I resulted in denitration. Diazotization and oxidation of 3,5-bis(4-amino-1,2,5-oxadiazol-3-yl)-1,2,4- triazole, its N-methyl and N-carboxy derivatives gave rise to the corresponding azido and nitro derivatives. Salts of 3,5-bis(4-amino-1,2,5-oxadiazol-3-yl)-1,2,4-triazol-5-acetic acid with nitrogen-containing bases were synthesized. It was established that the character of reaction products of 3,5-bis(4-amino-1,2,5-oxadiazol-3-yl)-1,2,4-triazole with formaldehyde depended on the acid-base properties of the medium.__________Translated from Zhurnal Organicheskoi Khirmii, Vol. 41, No. 2, 2005, pp. 270–276.Original Russian Text Copyright © 2005 by Sergievskii, Romanova, Mel’nikova, Tselinskii.     

3,5-二氯-2,4,6-三硝基苯胺及其衍生物的合成

分别以3,5-二氯苯胺为原料,经N保护、硝化、水解以及以1,3,5-三氯-2,4,6-三硝基苯(TCTNB)为原料,经叔丁胺化,再在三氟乙酸中脱叔丁基2种方法合成了3,5-二氯-2,4,6-三硝基苯胺。 与甲胺反应,合成了3,5-二甲氨基-2,4,6-三硝基苯胺,收率85%,再用混酸硝化合成了3,5-二甲硝胺基-2,4,6-三硝基苯胺的硝酸盐,收率70%。 采用核磁共振、质谱、红外和元素分析等进行了结构表征。 探讨了不同参数下TCTNB的氨化结果。 优化的条件为：n(TCTNB)∶n(叔丁胺)=1∶2,CuO为催化剂,KHCO3为碱。     

新型3,5-二芳基吡唑衍生物的合成与抑菌活性

以2-氯苯甲醛与2,4-二氯苯乙酮缩合形成α,β不饱和酮,然后和水合肼关环形成3-(2,4-二氯苯基)-5-(2-氯苯基)吡唑结构骨架,合成了8个未见文献报道的3-(2,4-二氯苯基)-5-(2-氯苯基)-4,5二氢-N-酰基吡唑类衍生物。经过元素分析、红外光谱、核磁共振氢谱测试技术对其结构进行了表征。对新合成的化合物进行了初步生物活性测试结果表明,在化合物的质量浓度为50 mg/L时,化合物3f对水稻纹枯菌和稻瘟病菌的抑菌率分别为55.2%和57.1%。化合物3g对水稻纹枯菌、稻瘟病菌和油菜菌核菌的抑菌率分别为52.3%、60.0%和50.4%。     

微波辐射下合成3-芳基-9-氨基-1,2,3,4-四氢吖啶-1-酮衍生物

在微波辐射和对甲基苯磺酸的催化作用下, 5-芳基-1,3-环己二酮与邻氨基苯甲腈进行缩合反应, 得到了N-取代的2-氨基苯甲腈衍生物, 在K₂CO₃和Cu₂Cl₂的催化作用下进一步合环, 得到3-芳基-9-氨基-1,2,3,4-四氢吖啶-1-酮衍生物, 用LiAlH₄还原羰基得到3-芳基-9-氨基-1,2,3,4-四氢吖啶-1-醇衍生物. 新合成化合物的结构均经元素分析、红外光谱和核磁共振光谱予以确认.