联二烯丁基硫醚衍生物合成呋喃的反应

本文报道以联二烯丁基硫醚为起始物的呋喃衍生物的合成方法.实验结果表明,β-联二烯丁基硫醚醇在氢化钠的作用下以很高的收率环化生成一个苯硫基离去的呋喃产物,β-联二烯丁基硫醚醛与外加亲核试剂作用后能得到多一个取代的类似呋喃产物,而β-联二烯丁基硫醚酮在P2O5的促进下也能环化生成呋喃衍生物.     

Synthesis of furan from allenic sulfide derivatives

In this paper, we report the synthesis of furan derivatives from allenic sulfides. By the reaction with NaH, β-Hydroxyl allenic sulfides were found to generate furan products in excellent yields with the removal of phenylthio group. β-Aldehyde allenic sulfides were found to give similar furan products with one more substituent when treated with additional nucleophilic reagents. β-ketone allenic sulfides can also cyclize to give furan derivatives with the promotion of P₂O₅.     

无溶剂条件下5,6-二取代-2,3-吡啶二酮的合成

在无溶剂条件下, 由3-羟基-2(1H)-吡啶酮与取代苯胺在NaIO₃作用下合成了一系列5,6-二取代-2,3-吡啶二酮, 产物结构由元素分析, ¹H NMR, MS, IR得到确认. 该方法具有反应条件温和、操作简单和产率高等优点.     

Facile microwave-mediated transformations of 2-butene-1,4-diones and 2-butyne-1,4-diones to furan derivatives

Several di- and triarylfuran derivatives were prepared in high yields from but-2-ene-1,4-diones/but-2-yne-1,4-diones using formic acid in the presence of a catalytic amount of palladium on carbon and in poly(ethylene glycol)-200 medium in a one-pot operation under microwave irradiation (1-5 min).     

Synthesis and transformations of furan derivatives

Condensation of thiosemicarbazones of furfural, 3-(2-furyl)acrolein, as well as their 5-nitro derivatives with chloroacetone by boiling in alcohol or acetic acid gives the corresponding 4-methylthiazolyl-(2)hydrazones. 4-Methylthiazolyl-(2)-hydrazones of 5-nitro-2-acetylfuran and 5-nitro-2-furfurilydeneacetone can be prepared by condensing the corresponding thiosemicarbazones with chloroacetone by heating with glacial acetic acid containing fused sodium acetate.For Part IV see [1].     

Synthesis of isoquinoline derivatives of quinoxalin-2-one from pyrrolo[2,1-a]isoquinoline-2,3-diones and o-phenylenediamine

Reactions of 5,5-dialkyl-2,3,4,5-tetrahydropyrrolo[2,1-a]isoquinoline-2,3-diones with o-phenylenediamine in the presence of a catalytic amount of hydrogen chloride or p-toluenesulfonic acid involved opening of the pyrrole ring with formation of 3-(3,3-dialkyl-1,2,3,4-tetrahydroisoquinolin-1-ylidenemethyl)quinoxalin-2(1H)-ones. The presence of an enamine fragment in the products was confirmed by reaction with oxalyl chloride.     

Synthesis of 5H-naphtho[2,3-c]phenothiazine-8,13-diones from 1-arylthio-2-azidoanthraquinones

Thermolysis of 1-arylthio-2-azidoanthraquinones in DMSO at 150 °C afforded substituted 5H-naphtho[2,3-c]phenothiazine-8,13-diones. These compounds were also formed upon photolysis of azides at 77 K and were prepared in quantitative yields by the reactions of 1-arylthio-2-azidoanthraquinones with KOH in DMSO at 20 °C.     

Synthesis and some transformations of new 9-furylnaphtho[2,3-b]furan derivatives

The synthesis of a number of naphtho[2,3-b]furan derivatives, containing a furyl substituent in position 9 by intramolecular cyclization of 2-carboxy and 2-formylbis(5-alkylfur-2-yl)methanes is described. The reactivity of the title compounds in formylation, acetylation, nitration, and oxidation reactions has been investigated. It was shown that nitration of 2-methyl-9-(5-methyl-2-furyl)naphtho[2,3-b]furan-4-yl acetate leads to oxidative furan ring opening rather than to electrophilic substitution.     

Synthesis of a novel series of tetra-substituted furan[3,2-b]pyrroles

Furan[3,2-b]pyrroles are important isosteres for the indole scaffold in which the benzene ring is replaced by the furan ring. A series of novel tetra-substituted furan[3,2-b]pyrroles was synthesized from a simple furaldehyde. The divergent synthesis allows for substitution on multiple positions on the scaffold, creating the potential for the formation of large libraries.     

Synthesis of furan analogs of 1, 3, 5-triphenylpyrazoline derivatives

Furan analogs of chalcones are condensed with phenylhydrazine to give a number of ²-pyrazolines hitherto not described in the literature. It is shown that in , -unsaturated ketones, a nitro-group in the nucleus and remote from the carbonyl group makes cyclization to the corresponding ²-pyrazolines more difficult than does one adjacent to the carbonyl.     

Synthesis of tetra-substituted pyrazoles

A set of highly substituted pyrazoles bearing different functional groups on the pyrazole core was developed. Employing a suitable protecting group strategy we could regioselectively introduce various substituents in position 1, 3 and 4 of the pyrazole. This enabled the synthesis of various derivatives of a pyrazole–biscarboxamide with insecticidal activity. During the optimization process we focused on the precise exchange of carboxamide as well as other functional groups based on the concept of bioisosterism.     

Synthesis of derivatives of pyrazine-2,3-dicarboxylic acids and pyrazine-2,3-dicarbonamides from 2,3-dichloroquinoxaline

The synthesis of dimethyl 2,3-dichloropyrazine-5,6-dicarboxylate from dichloroquinoxaline has been effected. The nucleophilic substitution reactions of the compound obtained have been studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1548–1551, November, 1973.     

Synthesis of functionally substituted furan and resorcinol derivatives from dimethyl 3-oxopentanedioate

Russian Journal of Organic Chemistry - The alkylation of dimethyl 3-oxopentanedioate with 1,2-dibromoethane and 1,2,3-tribromopropane afforded C,C-(cyclopropane derivative) and C,O-dialkylation...     

Reaction of 4,5-Diaroyl-1H-pyrrole-2,3-diones with Thiosemicarbazide. Synthesis of 1H-Pyrazole-5-carboxamides

Russian Journal of Organic Chemistry - The reactions of 4,5-diaroyl-1H-pyrrole-2,3-diones with thiosemicarbazide and semicarbazide in­volved elimination of carbothioamide or carboxamide group...     

Reactions with benzo[b]thiophene-2,3-diones I: Synthesis of 2,3-dihydroxy-2,3-diaryl(aralkyl)benzo[b]thiophene derivatives

Benzo[b]thiophene-2,3-diones ( 1 ) react with Grignard reagents to yield 2,3-dihydroxy-2,3-diaryl(aralkyl)benzo[b]-thiophenes ( 2 ). The latter compounds yield 3,3-diaryl(aralkyl)-benzo[b]thiophene-2-ones ( 3 ) by pinacolone rearrangement. Treatment of 3 by hot ethanolic sodium hydroxide solution yields the corresponding carboxylic acids by hydrolytic heteroring opening.     

Synthesis and properties of furan derivatives. 5. Synthesis of 2-substituted benzoxazoles containing furan fragments

The condensation of imidates and imidate hydrochlorides of furan acids with o-aminophenols gives furyl derivatives of 2-substituted benzoxazoles. Such compounds are also formed in the reaction of furan acids with o-aminophenol in the presence of boric acid.Communication 4, see [1].I. M. Gubkin State Petroleum and Gas Academy, 117917 Moscow. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 896–901, July, 1996. Original article submitted April 16, 1996.