微波辐射下"一锅煮"法合成2-氨基-3-氰基-4-芳基-4H,5H-吡喃-[3,2-c]苯并吡喃-5-酮

以芳醛、4-羟基香豆素、丙二腈为原料,乙醇为能量转移剂,哌啶为催化剂,在微波辐射下一步合成了一系列2-氨基-3-氰基-4-芳基-4H,5H-吡喃-[3,2-c]苯并吡喃-5-酮,反应在40～60s时间内完成,产率60%～97%.     

微波辐射一步法合成吡喃和吡喃[2, 3-c]吡唑衍生物

芳醛、丙二腈与5,5-二甲基-1,3-环己二酮或3-甲基-1-苯基-2-吡唑啉-5-酮在乙醇溶剂中用哌啶作催化剂,经微波辐射一步合成了2-氨基-3-氰基-4-芳基-7,7-二甲基-5-氧代-5,6,7,8-四氢苯并吡喃和6-氨基-5-氰基-4-芳基-1,4-二氢吡喃[2,3-c]吡唑,反应在2～12min内完成,产率53%～91%。     

Reaction of 2-(5-aminopyrazol-1-yl)quinoxaline 4-oxides with dimethyl acetylenedicarboxylate

The reaction of 6-chloro-2-hydrazinoquinoxaline 4-oxide 6 with ethyl 2-(ethoxymethylene)-2-cyanoacetate or (1-ethoxyethylidene)malononitrile gave 2-(5-amino-4-ethoxycarbonylpyrazol-1-yl)-6-chloroquinoxaline 4-oxide 7a or 2-(5-amino-4-cyano-3-methylpyrazol-1-yl)-6-chloroquinoxaline 4-oxide 7b , respectively. The reaction of compound 7a or 7b with dimethyl acetylenedicarboxylate resulted in the 1,3-dipolar cycloaddition reaction and then ring transformation to afford 4-(5-amino-4-ethoxycarbonylpyrazol-1-yl)-8-chloro-1,2,3-trismethoxycarbonylpyrrolo[1,2-α]quinoxaline 8a or 4-(5-amino-4-cyano-3-methylpyrazol-1-yl)-8-chloro-1,2,3-trismethoxycarbonylpyrrolo[1,2-α]quinoxaline 8b , respectively.     

Fused sulfur-containing pyridine systems. 1. Synthesis and structures of tetrahydropyridothienopyridinone and tetrahydropyridothiopyranopyridinone derivatives

The reactions of N-methylmorpholinium 4-aryl(hetaryl)-5-cyano-2-oxo-1,2,3,4-tetrahydropyridine-6-thiolates with malononitrile and acetone in ethanol afforded substituted tetrahydropyridothienopyridinones. In the absence of acetone, tetrahydropyridothiopyranopyridinones were isolated as the major reaction products. The latter were also synthesized independently by the reactions of the above-mentioned thiolates with 2-amino-1,1,3-tricyanopropene. The structure of 2,4-diamino-10-(2-chlorophenyl)-3-cyano-5-imino-8-oxo-7,8,9,10-tetrahydro-5H-pyrido[2",3":2,3]thiopyrano[4,5-b]pyridine was established by X-ray diffraction analysis.     

水介质中吡喃并[3,2-c]吡喃-5-酮衍生物的三组分一锅合成

水介质中在氯化三乙基苄基铵(TEBAC)催化下, 芳醛与丙二腈和4-羟基-6-甲基吡喃-2-酮三组分一锅反应合成了一系列2-氨基-3-氰基-4-芳基-4H,5H-吡喃-5-酮. 该反应具有产率高、污染少、操作简单、环境友好等优点.     

Hydrolysis and acylation of imino group in E/Z-isomers of 3,4-dialkyl-8-amino-1-imino-6-morpholin-4-yl-2-oxa-7-azaspiro[4.4]nona-3,6,8-triene-9-carbonitriles

Acid-catalyzed hydrolysis of 3,4-dialkyl-substituted 8-amino-1-imino-6-morpholin-4-yl-2-oxa-7-azaspiro[4.4]nona-3,6,8-triene-9-carbonitriles under mild conditions led to the formation of 8-amino-6-morpholin-4-yl-1-oxo-2-oxa-7-azaspiro[4.4]nona-3,6,8-triene-9-carbonitriles, and their acylation afforded N-(8-amino-9-cyano-6-morpholin-4-yl-2-oxa-7-azaspiro-[4.4]nona-3,6,8-trien-1-ylidene)acetamides. The NMR spectra of compounds synthesized in contrast to the spectra of initial N-unsubstituted imins contained no doubled proton and carbon signals.     

An environmentally friendly synthesis of 1,4-dihydropyrano[2,3-c]pyrazole derivatives catalyzed by tungstate sulfuric acid

An efficient three-component synthesis of 6-amino-4-aryl-5-cyano-3-metriyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles via a reaction between 3-methyl-1-phenyl-2-pyrazolin-5-one,aromatic aldehydes and malononitrile using tungstate sulfuric acid as a catalyst was described.Mild conditions,good to excellent yields,easily available catalyst and easy work-up are the key features of this method.     

Synthesis of azolo[5,4-c]isoquinolines

Two pathways are presented for the synthesis of pyrazolo[5,4-c]isoquinoline derivatives: recyclization of 1-methyl-3-phenyl-4-cyano-6,7-dimethoxybenzo[c]pyrylium perchlorate upon treatment with hydrazine, and Bischler-Napieralski cyclization of substituted 5-amino-4-(3,4-dimethoxyphenyl)pyrazoles. A derivative of a new heterocyclic system, isoxazolo[5,4-c]isoquinoline, has also been obtained upon heating 5-amino-3-phenyl-4-(3,4-dimethoxyphenyl)isoxazole in a mixture of acetic anhydride and perchloric acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1092–1095, August, 1990.     

Efficient synthesis of 3H-imidazo[4,5-b]pyridines from malononitrile and 5-amino-4-(cyanoformimidoyl)imidazoles

1-Aryl-5-amino-4-(cyanoformimidoyl)imidazoles 2 were reacted with malononitrile under mild experimental conditions and led to 3-aryl-5,7-diamino-6-cyano-3H-imidazo[4,5-b]pyridines 5, when the reaction was carried out in the presence of DBU, or to 3-aryl-5-amino-6,7-dicyano-3H-imidazo[4,5-b]pyridines 3, in its absence. Both reactions evolved from the adduct formed by nucleophilic attack of the malononitrile anion to the carbon of the cyanoformimidoyl substituent. A 5-amino-1-aryl-4-(1-amino-2,2-dicyanovinyl)imidazole 4 was isolated when this reaction was carried out in the presence of DBU. The structure of compound 4 was confirmed by spectroscopic methods and by reaction with triethyl orthoformate and with acetic anhydride, leading respectively to 9-aryl-6-(cyanomethylidene)purines 11 and 12. Imidazole 2b was also reacted with ethyl acetoacetate, a carbon acid with a pK(a) comparable to that of malononitrile. Similar reaction conditions were used and the product isolated was a 6-carbamoyl-1,2-dihydropurine 10, showing that a different mechanism was operating in this case.     

Investigations on furopyridines. 10. Synthesis of 4-N-substituted 1H-furo[3,4]pyridin-3-ones

2-Amino or 2-hydrazino derivatives of pyridine or pyridinopyrazole were obtained by amination or hydrazination of 2-chloro-3-cyano-4-methoxy-6-methylpyridine. Acid hydrolysis of these derivatives leads to heterocyclization with formation of 4-amino-1H-furo[3,4-c]pyridines or pyrazolo[3,4-b]pyridine. The possibility to synthesize 4-arylamino-1H-furo[3,4-c]-pyridines from 4-chloro-6-methyl-1H-furo[3,4-c]-pyridine has been shown.V. S. Pustovoit All-Russian Oil-Bearing Crops Research Institute, Krasnodar 350038, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 61–66, January, 1999.     

硅胶键合N-丙基哌嗪n-丙酸钠作为可循环使用催化剂催化4H-吡喃衍生物合成(英文)

Silica‐bonded N‐propylpiperazine sodium n‐propionate(SBPPSP) was found to act as an efficient solid base for the preparation of a series of 4H‐benzo[b]pyran derivatives. SBPPSP was used as a recyclable heterogeneous solid base catalyst for the synthesis of 3,4‐dihydropyrano[c]chromenes, 2‐amino‐4H‐pyrans, 1,4‐dihydropyrano[2,3‐c]pyrazoles, and 2‐amino‐4H‐benzo[e]‐chromenes via the condensation reaction of dimedone, ethyl acetoacetate, 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5(4H)‐ one, and α‐naphthol, respectively, with aromatic aldehydes and malononitrile in refluxing aqueous ethanol. The heterogeneous solid base showed similar efficiency when reused in consecutive reactions.     

Reaction of Potassium 1,1,3,3-Tetracyano-2-(2,2-dimethylpropanoyl)propenide with 2-Sulfanylethanol

The reaction of potassium 2-(2,2-dimethylpropanoyl)-1,1,3,3-tetracyanopropenide with an equimolar amount of 2-sulfanylethanol afforded 2-{5-amino-2-(tert-butyl)-4-cyano-2-[(2-hydroxyethyl)sulfanyl]- 2,3-dihydrofuran-3-ylidene}propanedinitrile, whereas 4-amino-1-(tert-butyl)-1,6-bis[(2-hydroxyethyl)- sulfanyl]-3-imino-1,3-dihydrofuro[3,4-c]pyridine-7-carbonitrile was obtained in the reaction with excess 2-sulfanylethanol.     

Facile synthesis and antimicrobial evaluations of some novel pyrazolo[3,4-b]selenolo[3,2-e]pyrazines and their related heterocycles

A new series of pyrazolopyrazinoselenolotriazolopyrimidines was synthesized by a facile method based on condensation of 5-amino-3-methyl-1-phenyl-1H-pyrazolo[3,4-b]selenolo[3,2-e]pyrazine-6-carbonitrile ( 3 ) with triethyl orthoformate followed by intramolecular cyclization with hydrazine to afford 7-amino-8-imino-3-methyl-1-phenyl-1,8-dihydro-7H-pyrazolo[3″,4″:5′,6′]pyrazino[2′,3′:4,5] selenolo[3,2-d]pyrimidine ( 5 ). The latter compound was utilized as a multipurpose precursor for the construction of other new triazoles fused to the pyrazolopyrazino- selenolopyrimidine moiety. Alternatively, acetylation and chloro-acetylation of compound 3 using acetic anhydride and chloroacetyl chloride yielded the acetyl amino 11 and chloroacetamido 12 derivatives, respectively. Compound 12 underwent nucleophilic substitution upon reaction with morpholine to provide the morpholinyl acetamide 13 . Furthermore, the pyrazolopyridoselenolopyrazine ring system 14 was synthesized by the reaction of the o-amino-carbonitrile 3 with malononitrile. Assignment of the chemical structures for the new compounds was confirmed depending on elemental and spectral techniques. On the other hand, most of the synthesized compounds revealed promising results against various bacterial and fungal strains.     

Greener approach towards the facile synthesis of 1,4-dihydropyrano[2,3-c]pyrazol-5-yl cyanide derivatives at room temperature

This report describes triethylammonium acetate (TEAA) ionic liquid catalyzed one pot synthesis of 6-amino-4-aryl-5-cyano-3-methyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles by the reaction of aromatic aldehyde, malononitrile and 3-methyl-1-phenyl-2-pyrazolin-5-one at room temperature. TEAA plays dual role as reaction media and catalyst. It can also be easily recovered and reused in several runs. TEAA provides greener reaction protocol to present methodology which obviates the need of organic solvents, expensive and toxic catalyst.     

A Facile Synthesis of Ethyl-2-Methyl-5h-Chromeno[3,4-c]Pyridine-1-Carboxylates

4-Chloro-2H-3-chromene carbaldehydes (2a-i) on reaction with ethyl-3-aminocrotonate 3 gives ethyl-2-methyl-5H-chromeno[3,4-c]pyridine- 1- carboxylates 4a-i in good yields.     

Synthesis of furo[2,3-c]pyran and some properties of 2-amino derivatives of furo- and pyrrolo[2,3-c]pyrans

Thesynthesisof2-amino-5,5-dimethyl-3-cyano-4,5-dihydro-7H-furo[2,3-c]pyrananditspyrroleanalog was accomplished on the basis of 2,2-dimethyltetrahydro-4-pyranone. Their reaction with maleic anhydride, which leads to the formation of 3-amino-4-cyano-6,6-dimethyl-5,6-dihydro-8H-pyrano[c]-phthalic anhydride, was studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 316–318, March, 1991.     

Synthesis of the new ring system,Pyrazolo[3,4-d][1,3]diazepine. A novel route for the synthesis of azolo[1,3]diazepines

A reduction of the nitrile group of 5-amino-4-cyano-1-methylpyrazole ( 3 ) has provided the very versatile compound 5-amino-1-methylpyrazole-4-carboxaldehyde ( 4 ). The amino group of 4 was protected using di-methylformamide dimethylacetal and the aldehyde group was then reacted with trimethylsilyl cyanide to afford the moisture sensitive compound 5-[[(dimethylamino)methylene]amino]-4-[cyano(trimethylsiloxy)-methyl]-1-methylpyrazole ( 10 ). The cyano group of the cyanohydrin 10 was reduced using a cobalt boride catalyst to afford an intermediate aminomethyl group which was involved in an in situ annulation. This reaction provided 1-methyl-1,4,5,6-tetrahydropyrazolo[3,4-d][1,3]diazepin-4-ol, a derivative of the new ring system, pyrazolo[3,4-d][1,3]diazepine.     

2-氨基-3-氰基-4-芳基-6-甲氧基-1,4,9,10-四氢萘并[2,1-b]吡喃衍生物的一步合成

以芳醛、丙二腈和7-甲氧基-1,2,3,4-四氢萘-2-酮为原料,在六氢吡啶催化下以乙醇为溶剂,在室温合成了一系列新的2-氨基-3-氰基-4-芳基-6-甲氧基-1,4,9,10-四氢萘并[2,1-b]吡喃衍生物,反应条件温和,产率较高,并通过IR,1H NMR和元素分析表征产物的结构,还通过单晶X射线衍射分析确证产物的构象.     

Simple,Catalyst-Free,One-Pot Procedure for the Synthesis of 2-Amino-3-cyano-1,4,5,6-tetrahydropyrano[3,2-c]quinolin-5-one Derivatives

A one-pot, three-component reaction of 4-hydroxyquinolin-2(1H)-one, malononitrile, and various aldehydes for the synthesis of 2-amino-3-cyano-1,4,5,6-tetrahydropyrano[3,2-c]quinolin-5-one derivatives is reported. The reaction is performed without any catalysts in a mixed solvent of water and ethanol to give products in good yields. The present method provided a clean, simple, and economical alternative for the synthesis of potential biologically active pyranoquinoline derivatives.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Synthesis of new furopyrans and angularly fused furopyranochromenes from 3-arylmethylidenefuran-2-ones

Reactions of 5-aryl-3-arylmethylidenefuran-2-ones with malononitrile gave 6-amino-2,4-diaryl-4Hfuro[2,3-b]pyran-5-carbonitriles and 2-aryl-5-imino-5H,11bH-furo[3′,2′: 5,6]pyrano[3,4-c]chromen-6-amines as potentially biologically active substances.