Derivatives of 2, 6-dihydroxy-4, 5-dihydropyrimidines

Esters of DL-dihydroorotic acid have been obtained by catalytic hydrogenation of esters of orotic acid (using PtO₂ and 5% Rh on Al₂O₂ as catalysts), and by esterifying DL-dihydroorotic acid. Transesterification is observed with butyl dihydroorotate in the presence of secondary amines, and this ester is hydrolyzed in acid and alkaline media to dihydroorotic and ureidosuccinic acid, respectively.For Part I, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1286–1288, September, 1970.     

Polyesters from 2,6-dihydroxy-9,10-dihydro-9,10-ethanoanthracene and 2,6-dihydroxyanthracene

High molecular weight, film-forming, amorphous polyesters have been prepared from 2,6-dilydroxy-9,10-dihydro-9,10-ethanoanthracene with adipic, sebacic, dodecanoic, isophthalic, 4,4′-oxybibenzoic, 2,6-naphthoic, 4,4′-bibenzoic, and terephthalic acid. Thermal elimination of ethylene from these polymers has yielded the corresponding polyesters from 2,6-dihydroxyanthracene which were of high molecular weight, film forming, and crystalline.     

Synthesis of 4,5-dihydroxy-1,3-dinitroimidazolidin-2-one

A convenient method for the synthesis of 4,5-dihydroxy-1,3-dinitroimidazolidin-2-one from N,N′-dinitrourea is developed.     

2,6-Dihydroxy-4,5-dihydropyrimidine derivatives

Alkylamides of DL-4,5-dihydroorotic acid were synthesized by catalytic hydrogenation (5% Rh on Al₂O₃). The reaction of the n-butyl ester of DL-4,5-dihydroorotic acid with alkylamines and hydrazine gave N,N-dialkylamides, the dihydrazide of DL-ureidosuccinic acid, and the hydrazide of DL-4,5-dihydroorotic acid. The products of the condensation of the latter with aromatic aldehydes were obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 105–108, January, 1972.     

Synthesis of Aminomethyl Derivatives of 2,6-Dihydroxynaphthalene

Russian Journal of Organic Chemistry - Mono- and bis-aminomethyl derivatives of 2,6-dihydroxynaphthalene containing cyclic amine residues have been synthesized, and the formation of a strong...     

Synthesis of Novel Imidazole-4,5-Dicarboxamide Derivatives

Imidazolecarboxamide derivatives have been known to exhibit biological activity, especially antiparasitic activity.¹ To date imidazole-4(5)-monocarboxamide derivatives and symmetrical imidazole-4,5-dicarboxamide derivatives have been investigated.¹ However, unsymmetrical imidazole-4,5-dicarboxamide derivatives, having different carboxamide groups, have not been investigated. Therefore, the author was prompted to devise a synthetic method for unsymmetrical diamide derivatives.     

Efficient synthesis of 3,4- and 4,5-dihydroxy-2-amino-cyclohexanecarboxylic acid enantiomers

An efficient method for the synthesis of (1S,2R,4R,5S)- and (1R,2R,4R,5S)-2-amino-4,5-dihydroxycyclohexanecarboxylic acids (?)-6 and (?)-9 and (1R,2R,3S,4R)- and (1S,2R,3S,4R)-2-amino-3,4-dihydroxycyclohexanecarboxylic acids (?)-15 and (?)-18 was developed by using the OsO₄-catalyzed oxidation of Boc-protected (1S,2R)-2-aminocyclohex-4-enecarboxylic acid (+)-2 and (1R,2S)-2-aminocyclohex-3-enecarboxylic acid (+)-11. Good yields were obtained. The stereochemistry of the synthesized compounds was proven by NMR spectroscopy.     

Reactions of derivatives of N-aryl-2-methyl-3-ethoxycarbonyl-4,5-dihydroxy-6-bromoindoles

Some 4,5-dihydroxyindoles, with an acetoacetic ester substituent at the 7 position were used to synthesize 7-acetonyl-4,5-dihydroxyindoles. Methylation of these compounds gave 4-hydroxy-5-methoxy- and 4,5-dimethoxyindoles. On reaction with hydroxylamine, these compounds were converted to the oximes. Oxidation of 4,5-dihydroxyindoles with nitric acid gave 4,5-indolequinones.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1054–1058, August, 1987.     

Synthesis and Reaction Chemistry of the Disodium Alkoxide of 2,6-Bis(trifluoromethyl)-2,6-dihydroxy-3,3,4,4,5,5-hexafluorooxane

The disodium alkoxide of 2,6-bis(trifluoromethyl)-2,6-dihydroxy-3,3,4,4,5,5-hexafluorooxane, C(7)F(12)O(3)Na(2), 1, was prepared by reaction of the corresponding diol with MeONa in MeOH. This cyclic alkoxide readily mimics the reaction chemistry of the lithium and sodium alkoxides of perfluoropinacol. The reaction of the alkoxide 1 with covalent dichlorides and metallocene dichlorides yields a series of novel bicyclic ring systems. The crystal structure of the trioxasilane, 3, formed from (CH(3))(2)SiCl(2) was determined to provide structural information about these ring systems. Crystal data: C(9)H(6)O(3)F(12)Si, fw = 418.21 u, orthorhombic space group, Pnma (No. 62), a = 15.822(3) ?, b = 12.163(3) ?, c = 7.373(2) ?, V = 1418.9(4) ?(3), and D(calc) = 1.96 g cm(-)(3) for Z = 4 (molecule possesses mirror symmetry). Least-squares refinement on 1075 observed reflections (I > 3sigma(I)) converged with R = 0.0357 and R(w) = 0.0478.     

Synthesis of Novel 3,7-Dihydro-purine-2,6-dione Derivatives

Forty-six novel 3,7-dihydro-purine-2,6-dione derivatives (substituted xanthines) with great structural diversity were synthesized for biological activity screening. Three series of substituted xanthine analogs have been prepared in moderate to excellent yields.     

Synthesis of new ring-fused thiocarbamates by condensation of 2-thioxo-and 2-oxo-1,3-dialkyl-4,5-dihydroxy-4,5-diphenylimidazolidines with KSCN

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Synthesis of new unsymmetrical 4,5-dihydroxy-2-imidazolidinones. Dynamic NMR spectroscopic study of the prototropic tautomerism in 1-(2-benzimidazolyl)-3-phenyl-4,5-dihydroxy-2-imidazolidinone

The acid-catalyzed cyclocondensation in refluxing acetonitrile of aqueous glyoxal with N-heteroaryl-N'-phenylureas 4a-f (heteroaryl = 2-thiazolyl, 2-pyrimidinyl,2-pyrazinyl, 2-pyridinyl, 3-pyridinyl and 2-benzimidazolyl) led to the formation of the corresponding 1-heteroaryl-3-phenyl-4,5-dihydroxy-2-imidazolidinones 5a-f. All the products were characterized by elemental and spectroscopic analyses. The free-energy barrier (Delta G not equal) for prototropic tautomerism in 1-(2-benzimidazolyl)-3-phenyl-4,5-dihydroxy-2-imidazolidinone (5f) was determined by dynamic NMR studies to be 81 +/- 2 KJ mol(-1).     

Synthesis of 2,6-Dideoxy-6-Thio Derivatives of KDO

ABSTRACT

Ammonium 2,3,6-trideoxy-2,6-epithio-D-manno-2-octenoate (8), ammonium 2,3,6-trideoxy-2,6-epithio-D-glycero-D-talo-octanoate (10a), ammonium 2,3,6-trideoxy-2,6-epithio-D-glycero-D-galacto-octanoate (10b) and ammonium 2,3,6-trideoxy-2,6-epithio-oxa-D-glycero-D-galacto-octanoate (13) have been synthesised as potential inhibitors of the enzyme CMP-KDO synthetase. The key step in the synthesis of 8 was the elimination of water from methyl 3,6-dideoxy-4,5:7,8-di-O-isopropylidene-6-thio-D-manno-2-octulosonate (4) using chlorodiphenylphosphine, imidazole and bromine to give the unsaturated methyl 2,3,6-trideoxy-2,6-epithio-4,5:7,8-di-O-isopropylidene-D-manno-2-octenoate (5). For the synthesis of 10a and 10b, zinc reduction of methyl 3,6-dideoxy-4,5:7,8-di-O-isopropylidene-6-S-(4-methoxybenzyl)-6-thio-2-O-(trichloro-tert-butoxycarbonyl)-D-manno-2-octenoate (2) gave an epimeric mixture of an α-hydroxyester 6 which was ring closed by in situ activation of the hydroxyl group using triphenylphosphine and tri-iodoimidazole followed by cleavage of the p-methoxybenzyl group to give 7a and 7b, which then were deprotected to give 10a and 10b.     

2,6-二取代苯胺衍生物生物活性的研究进展

综合 8 0年代后期以来的文献报道 ,对 2 ,6 二取代苯胺衍生物的生物活性 ,结构与活性之间的关系 ,降解机制和作用方式进行了综述。