Reaction of Aminobenzimidazoles with 4-Hydroxy-6-methyl-2-pyrone and 4-Hydroxycoumarine

6- and 7-(4-hydroxy-6-methyl-2-oxo-1-pyridyl)benzimidazoles and 1-(6- and 7-benzimidazolyl)-4-hydroxy-2-oxoquinolines were synthesized by reaction of aminobenzimidazoles with 4-hydroxy-6-methyl-2-pyrone and 4-hydroxycoumarine.     

Ring Opening of 4-Arylamino-2-tert-butyl-5-oxo-2,5-dihydrofuran-2-yl Acetates with Aromatic and Heterocyclic Amines

Russian Journal of Organic Chemistry - Reactions of 4-arylamino-2-tert-butyl-5-oxo-2,5-dihydrofuran-2-yl acetates with an equimolar amount of aromatic or heterocyclic amine in toluene involves...     

对-甲苯乙酮与芳香醛和芳香胺的Mannich反应

Mannich反应是合成新化合物的重要方法 [1] ,其对应的产物 Mannich碱常常具有广泛的生物活性 [2 ] .文献报道 ,对 -甲苯乙酮的 Mannich碱具有抑癌 [3]和麻醉拮抗 [4 ]等生物活性 ,但是文献中对 -甲苯乙酮 Mannich碱的合成却是从胺交换法 [5] 、酮交换法 [6] 、查耳酮与胺的 Michael加成[7] 、Schiff碱与酮的缩合 [8～ 14 ] 、β-内酰胺与有机锂的亲核裂解 [15] 等间接方法得到的 .即使是从直接法合成 ,一般也是甲醛参与的 Mannich反应 .虽然芳香醛和芳香胺同时参与的 Mannich反应已有报道 [16] ,但对 -甲苯乙酮与芳香醛和芳香胺直接进行…     

Cyanoacetylene and Its Derivatives: XXXIII. One-Pot Stereoselective Synthesis of Bis-iminodihydrofurans from 4-Hydroxy-4-methyl-2-pentynonitrile and Aromatic Amines

4-Hydroxy-4-methyl-2-pentynonitrile reacts with aniline, N-methylaniline, and 2-naphthylamine under mild conditions (20–80°C) to afford the corresponding 4-arylamino-2-(2-imino-5,5-dimethyl-2,5-dihydro-4-furylimino)-5,5-dimethyl-2,5-dihydrofurans in one preparative step. According to the X-ray diffraction data, both imino groups in the products have syn configuration with respect to the ring oxygen atom.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 6, 2005, pp. 903–909.Original Russian Text Copyright © 2005 by Trofimov, Mal’kina, Shemyakina, Kudyakova, Sokolyanskaya, Sinegovskaya, Albanov, Smirnov, Kazheva, Chekhlov, D’yachenko.     

A New Facile Synthesis of 4-Arylamino-5, 7-Dinitrobenzofurazans

The reaction of 4,6-dinitrobenzofuroxan 1 with alkali metal salts of formanilides 2 affords 6′-nitrogen bonded Meisenheimer complexes 3 which upon heating in water form 4-arylamino-5, 7-dinitrobenzofurazans 5 in good lides in the presence of sodium hydroxide is also described.     

A Convenient Synthesis of Phenoxy Carboxamides from Phenols Using the Mitsunobu Reaction

An efficient method for the direct conversion of phenols to phenoxy carboxamides is presented. This synthetic methodology is utilized to produce potent human leukocyte elastase inhibitors.     

Reaction of 4-Oxocyclohexane-1,1,2,2-tetracarbonitriles and 5-Hydroxy-7-oxo-6-azabicyclo[3.2.1]octane-1,2,2-tricarbonitriles with Amines

New methods have been developed for the synthesis of fused amino-substituted pyrrolidinones and dihydropyrrolones. 4-Oxocyclohexane-1,1,2,2-tetracarbonitriles react with ammonia, hydrazine, and hydroxylamine to give, respectively, 5-amino-, 5-hydrazino-, and 5-hydroxylamino-7-oxo-6-azabicyclo[3.2.1]octane-1,2,2-tricarbonitriles, while with phenylhydrazine, semicarbazide, and thiosemicarbazide, 6-hydrazono-, 6-semicarbazono-, and 6-thiosemicarbazono-3-amino-1-oxo-3a,4,5,6,7,7a-hexahydro-1H-isoindole-3a,7a-dicarbonitriles are formed. The latter can also be obtained under analogous conditions from 5-hydroxy-7-oxo-6-azabicyclo[3.2.1]octane-1,2,2-tricarbonitriles. Reactions of 5-hydroxy-7-oxo-6-azabicyclo[3.2.1]octane-1,2,2-tricarbonitriles with diethylamine or triethylamine give 3-amino-1,6-dioxo-3a,4,5,6,7,7a-hexahydro-1H-isoindole-3a,7a-dicarbonitriles.     

Triphenylphosphine-Mediated Serendipitous Synthesis of Alkyl Cinnamates Through the Reaction of 3-Hydroxy-4-Methoxybenzaldehyde and Dialkyl Acetylenedicarboxylates

Abstract

Alkyl cinnamates are formed in fairly good yields from the reaction of dialkyl acetylenedicarboxylates and 3-hydroxy-4-methoxybenzaldehyde in the presence of triphenylphosphine.     

3-Hydroxy-4-pyrones as Precursors of 4-Methoxy-3-oxidopyridinium Ylides. An Expeditious Entry to Highly Substituted 8-Azabicyclo[3.2.1]octanes

3-Hydroxy-4-pyridones, which are easily prepared from commercially available 3-hydroxy-4-pyrones, can be readily transformed into 4-methoxy-3-oxidopyridinium ylides by treatment with methyl trifluoromethanesulfonate and subsequent deprotonation with a non-nucleophilic base. These ylides are capable of undergoing cycloaddition to several electron-deficient alkenes, thus allowing the synthesis of highly functionalized azabicyclo[3.2.1]octane moieties. The rich substitution patterns of these frameworks might allow their divergent conversion to a variety of natural and non-natural tropane alkaloids.     

Yb(OTf)3催化苯乙酮、芳香醛和芳香胺的Mannich反应:三组分 "一锅法"合成β-氨基酮衍生物

报道了稀土化合物Yb(OTf)3催化的苯乙酮、芳香醛和芳香胺Mannich反应,三组分"一锅法"合成了一系列的β-氨基酮衍生物.该方法操作简单、条件温和、产率较高、催化剂可重复使用,且对环境友好.     

芳香胺和酚溴化的新工艺

研究了在室温下,N-溴丁二酰亚胺对芳香胺和酚的溴化工艺,在CHCl3、EtOH或EtOH/CHCl3溶剂中,用等摩尔的N-溴丁二酰亚胺可将某些芳香胺和酚(考察了5种反应底物)选择性地一溴化,产率92%~98%,N-溴丁二酰亚胺和反应底物摩尔比为2∶1;某些芳香胺和酚被专一地二溴化(考察了5种反应底物),产率90%~97%。 反应无须催化剂,投料后室温搅拌,反应条件温和,产品只需过滤洗涤即可纯化,操作简便。     

Base-Mediated Biginelli-Like Reaction Ignited by Aromatic Isocyanate: A Facile One-Pot Synthesis of N 4-Aryl-5-carboxyl-6-methyl Cytimidine Derivatives

The new three-component Biginelli reaction of aromatic isocyanate, ethyl acetoacetate, and substituted urea (or thiourea as well as guanidine) is described for the first time. In this reaction, N ⁴-aryl-5-carboxyl-6-methyl cytimidine derivatives were obtained in moderate to excellent yields by employing DBU as a highly effective catalyst. This methodology provides several advantages such as good functional group tolerance, excellent yields, atom efficiency, and experimental simplicity.     

A Novel Synthesis of N-Methyl-N-aryl Carbamates from Aromatic Amines and Dimethyl Carbonate Catalyzed by K2CO3／Bu4NBr

A facile synthesis of N-methyl-N-aryl carbamates from aromatic amines and dimethyl carbonate (DMC) has been achieved with high yields in the presence of potassium carbonate (K2CO3) and tetrabutylammonium bromide (Bu4NBr) under solvent-free conditions.     

A Facile and Practical Procedure for the Synthesis of 8-Hydroxy-4-oxochroman Derivatives

Abstract: Novel 8-hydroxy-4-oxochroman derivatives were prepared from appropriate 4-chromanones via the Baeyer-Villiger oxidation followed by an intramolecular Fries rearrangement.     

A study of the acylation of 4-hydroxy-6-methyl-2-pyrone and 4 hy(lroxy-6-phenyl-2-pyrone

The acylation of 4-hydroxy-6-melhyl-2-pyrone (1) and 4-hydroxy-6-phenyl-2-pyrone (XXII) with aliphatic acid anhydrides, or with aliphatic acid chlorides in trifluoroacetic acid, has been found to product; first the corresponding ester, which then rearranges, partially or wholly, depending on the conditions and on the nature of the acyl moiety, to form the corresponding 3-acylpyrone. With aromatic acid chlorides in pyridine or in trichloroacetic acid only the corresponding ester was obtained. These esters, however, could be rearranged to the corresponding 3-acylpyrones with aluminum chloride. Acetoaeetylation of 1 and 4-hydroxycoumarin (XXIX) with diketene gave, in both cases, the C-acetoacetylated product.     

4-Hydroxy-2-quinolones. 36. Synthesis of 2-R-oxazolo[4,5-c]quinolin-4(5H)-ones

We consider different variants for synthesis of 2-R-oxazolo[4,5-c]quinolin-4(5H)-ones based on 3-amino-1H-2-oxo-4-hydroxyquinolines and their 3-N-acyl derivatives. We show, that in the latter case, formation of the oxazole ring is possible via two routes, depending on the nature of the substituent on the acyl residue. For Communication 35, see [1]. Ukrainian Pharmaceutical Academy, Kharkov 310002. Translated from Khimiya Geterotsiklicheskikh Soedinenii. No. 11. pp. 1536–1541, November, 1997.