scholarly journals 2-[3-(Trifluoromethyl)phenyl]furo[3,2-b]pyrroles: synthesis and reactions

2005 ◽  
Vol 3 (2) ◽  
pp. 311-325 ◽  
Author(s):  
Peter Gajdoš ◽  
Soňa Pavlíková ◽  
Filip Bureš ◽  
Alžbeta Krutošíková
Keyword(s):  
Reaction Time ◽  
Carboxylic Acid ◽  
Acetic Anhydride ◽  
Microwave Irradiation ◽  
Hydrazine Hydrate ◽  
Methyl Iodide ◽  
Benzyl Chloride ◽  
Hydrazine Derivatives ◽  
Condensation Reactions ◽  
Hydrolysis Of

AbstractThe synthesis and reactions of methyl 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole-5-carboxylate (1a) are described. Upon reaction with methyl iodide, benzyl chloride, or acetic anhydride, this compound gave N-substituted products 1b-d. By hydrolysis of compounds 1a-c, the corresponding acids 2a-c were formed, or by reaction with hydrazine-hydrate, the corresponding carbohydrazides 3a-c were formed. By heating 2-[3-(trifluoromethyl)phenly]-4H-furo[3,2-b]pyrrole-5-carboxylic acid (2a) in acetic anhydride, 4-acetyl-2-[3-(trifluoromethyl)phenyl]furo[3,2-b]pyrrole (4) was formed. By hydrolysis of 4, 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole (5a) was formed, and reactions with methyl iodide or benzyl chloride gave N-substituted products 5b-c. The reaction of 4 with dimethyl butynedioate gave substituted benzo[b]furan 6. Compound 3a reacted with triethyl orthoesters giving 7a-c, which afforded with phosphorus (V) sulphide the corresponding thiones 8a-c. The thiones 8a-c reacted with hydrazine hydrate to form hydrazine derivatives 9a-c. The reaction of triethyl orthoformiate with compounds 9a-c led to furo[2′,3′: 4,5]pyrrolo[1,2-d][1,2,4]triazolo[3,4-f][1,2,4]triazines 10a-c. Hydrazones 11a-c were formed from 3a-c and 5-[3-(trifluoromethyl)phenyl]furan-2-carboxaldehyde. The effect of microwave irradiation on some condensation reactions was compared with “classical” conditions. The results showed that microwave irradiation shortens the reaction time while affording comparable yields.

Microwave Irradiated Acetylation of p-Anisidine: A Step towards Green Chemistry

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Mousumi Chakraborty ◽  
Vaishali Umrigar ◽  
Parimal A. Parikh
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Green Chemistry ◽  
Acetic Anhydride ◽  
Microwave Irradiation ◽  
Organic Solvent ◽  
Reaction Times ◽  
Microwave Energy ◽  
Operating Parameters ◽  
Feed Composition

The present study aims at assessing the effect of microwave irradiation against thermal heat on the production of N-acetyl-p-anisidine by acetylation of p-anisidine. The acetylation of p-anisidine under microwave irradiation produces N-acetyl-p-anisidine in shorter reaction times, which offers a benefit to the laboratories as well as industries. It also eliminates the use of excess solvent. Effects of operating parameters such as reaction time, feed composition, and microwave energy and reaction temperature on selectivity to the desired product have been investigated. The results indicate as high as a 98% conversion of N-acetyl-p-anisidine can be achieved within 12-15 minutes using acetic acid. The use of acetic acid as an acetylating agent against conventionally used acetic anhydride eliminates the handling of explosive acetic anhydride and also the energy intensive distillation step for separation of acetic acid. Organic solvent like acetic anhydride are not only hazardous to the environment, they are also expensive and flammable.

Fluorine-Containing Heterocycles: Part I. Synthesis of New 7-(2-thienyl)-9-Trifluoromethylpyrido[3′,2′:4,5]Thieno[3,2-d]Pyrimidines and Related Fused Tetracyclic Systems

2005 ◽  
Vol 2005 (3) ◽  
pp. 147-154 ◽  
Author(s):  
Etify A. Bakhite ◽  
Abdu E. Abdel-Rahman ◽  
Elham A. Al-Taifi
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Formic Acid ◽  
Hydrazine Hydrate ◽  
Methyl Iodide ◽  
Phosphorus Oxychloride ◽  
Diethyl Malonate ◽  
Triethyl Orthoformate ◽  
Dimroth Rearrangement ◽  
Ethyl Chloroacetate

3-amino-6-(2-thienyl)-4-trifluoromethylthieno[2,3-b]pyridine-2-carboxamide (3) and 2-carbonitrile analogue 5 were prepared by reaction of 3-cyano-6-(2-thienyl)-4-trifluoromethylpyridine-2(1H)-thione (1) with chloroacetamide or chloroacetonitrile respectively. Heating compound 3 with triethyl orthoformate led to the formation of pyridothienopyrimidinone derivative 6. Reaction of 6 with phosphorus oxychloride produced 4-chloropyrimidine derivative 7 which underwent some nucleophilic displacements upon treatment with thiourea, piperidine, morpholine or hydrazine hydrate to give the target 4-substituted pyridothienopyrimidines 8, 10a, 10b and 11 respectively. Reaction of compound 8 with methyl iodide or ethyl chloroacetate gave compounds 9a,b. The condensation of 3-amino-6-(2-thienyl)-4-trifluoromethyl-thieno[2,3-b]pyridine-2-carbonitrile (5) with triethyl orthoformate led to the formation of methanimidate derivative 21 which upon treatment with hydrazine hydrate gave the target 3-amino-3,4-dihydro-4-imino-7-(2-thienyl)-9-trifluoromethylpyrido[3′,2′:4,5] thieno[3,2-d]pyrimidine (22). The reactions of compounds 11 and 22 with some reagents namely; triethyl orthoformate, acetic anhydride, formic acid, acetic acid, acetylacetone benzaldehyde and/or diethyl malonate were carried out and their products were identified, in most cases as [1,2,4]triazolopyridothienopyrimidines via Dimroth rearrangement.

Synthesis of 2-[3-(trifluoromethyl)phenyl]furo[3,2-c]pyridine derivatives

2009 ◽  
Vol 63 (5) ◽  
Author(s):  
Ivana Bradiaková ◽  
Tatiana Ďurčeková ◽  
Naďa Prónayová ◽  
Anton Gatial ◽  
Alžbeta Krutošíková
Keyword(s):  
Carboxylic Acid ◽  
Nucleophilic Substitution ◽  
Chlorine Atom ◽  
Methyl Iodide ◽  
Secondary Amines ◽  
Pyridine Derivatives ◽  
Hydrolysis Of

Abstract2-[3-(Trifluoromethyl)phenyl]-4,5-dihydrofuro[3,2-c]pyridin-4-one (I) was prepared by a three-step synthesis. Its reaction with phosphorus sulfide rendered thione II which was methylated to 2-[3-(Trifluoromethyl)phenyl]-4-methylsulfanylfuro[3,2-c]pyridine (III). 5-Methyl-2-[3-(trifluoromethyl)phenyl]-4,5-dihydrofuro[3,2-c]pyridin-4-one (IV) was obtained by the reaction of I with methyl iodide in PTC conditions. The chlorine atom in derivate V was replaced with heterocyclic secondary amines via nucleophilic substitution and 4-substituted furopyridines VIa and VIb were thus prepared. 2-[3-(Trifluoromethyl)phenyl]furo[3,2-c]pyridine-4-carboxylic acid (VII) was obtained by hydrolysis of the corresponding carbonitrile Va.

Catalytic Effects of Super Acid SO42-/γ-Al2O3 to PET Depolymerization under Microwave Irradiation

2012 ◽  
Vol 550-553 ◽  
pp. 280-283 ◽  
Author(s):  
Hong Mei Yan ◽  
Yong Shuai Ma ◽  
Wei Lu Zhang ◽  
Dong Zhang
Keyword(s):  
Reaction Time ◽  
Microwave Irradiation ◽  
Polyethylene Terephthalate ◽  
Catalytic Hydrolysis ◽  
Whole Process ◽  
Morphology Analysis ◽  
Different Temperatures ◽  
Super Acid ◽  
Catalytic Effects ◽  
Hydrolysis Of

The effects of different temperatures on catalytic hydrolysis of polyethylene terephthalate(PET) by solid super acids SO42-/γ-Al2O3as a catalyst under microwave irradiation were studied, and in the meantime, the morphology analysis of the undepolymerized PET under the same temperature was investigated by SEM. The results indicate that the depolymerization rate of PET is seriously influenced by reaction time and temperature. The depolymerization mechanism is changed by the solid super acid SO42-/γ-Al2O3, and the depolymerization rate is higher than that of with no catalyst in the whole process of reaction.

Microwave Assisted Synthesis of Isoquercitrin Using Enzymatic Hydrolysis of Rutin

2014 ◽  
Vol 1033-1034 ◽  
pp. 311-314 ◽  
Author(s):  
Jun Wang ◽  
Guo Xia Sun ◽  
An Gong ◽  
Xiang Yang Wu
Keyword(s):  
Reaction Time ◽  
Enzymatic Hydrolysis ◽  
Microwave Irradiation ◽  
Microwave Assisted Synthesis ◽  
Rapid Synthesis ◽  
Reaction Efficiency ◽  
Microwave Assisted ◽  
Hydrolysis Of

A novel and rapid synthesis of isoquercitrin using enzymatic hydrolysis of rutin under microwave irradiation was investigated. In the [Bmim][BF4]-buffer (pH 9.0) system under microwave irradiation, rutin conversion, isoquercitrin yield and quercetin yield were 89.18%, 84.74% and 2.79%, respectively, in conditions of 5 min and 30 °C. The preparation cost of isoquercitrin was significantly reduced by decreasing reaction time (from 10 h to 5 min) and increasing reaction efficiency (by 120 times).

Silica sulfuric acid-catalyzed expeditious environment-friendly hydrolysis of carboxylic acid esters under microwave irradiation

2008 ◽  
Vol 62 (6) ◽  
Author(s):  
Zheng Li ◽  
Jing Liu ◽  
Xue Gong ◽  
Xuerong Mao ◽  
Xiunan Sun ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Carboxylic Acid ◽  
Microwave Irradiation ◽  
High Yield ◽  
Silica Sulfuric Acid ◽  
Environment Friendly ◽  
Acid Catalyzed ◽  
Work Up ◽  
Hydrolysis Of ◽  
Acid Esters

AbstractSilica sulfuric acid was found to be an efficient, recoverable, reusable and environment-friendly catalyst for the fast hydrolysis of various carboxylic acid esters in high conversions and selectivities under microwave irradiation conditions. This protocol has the advantages of no corrosion, no environmental pollution, high reaction rate, high yield, and simple work-up procedure.

STUDIES ON STOBBE CONDENSATION: REACTIONS OF ALDEHYDES AND KETONES WITH DIMETHYL METHYLSUCCINATE

1965 ◽  
Vol 43 (4) ◽  
pp. 928-934 ◽  
Author(s):  
A. M. El-Abbady ◽  
H. H. Mousa
Keyword(s):  
Acetic Anhydride ◽  
Alkaline Hydrolysis ◽  
Sodium Acetate ◽  
Condensation Reactions ◽  
Aldehydes And Ketones ◽  
Hydrolysis Of

Benzaldehyde, o-methoxybenzaldehyde, p-chlorobenzaldehyde, benzophenone, and acetophenone are condensed with dimethyl methylsuccinate in the presence of potassium tert-butoxide to give the corresponding β-half-esters. In the case of o-methoxybenzaldehyde the lactonic acid (IX) is also obtained. The β-half-esters are cyclized by sodium acetate and acetic anhydride to the corresponding acetoxynaphthoates which are converted into their methoxynaphthoates. Alkaline hydrolysis of the β-half-esters yields the corresponding itaconic acids, the anhydrides of which are converted to their α-half-esters.

Stereoselective Methylation of 1-(Diphenylphosphanyl)-2-[(methoxycarbonyl)methyl]ferrocene. The Crystal Structures of the Methylated Ester and Its Palladium(II) Complex with an Auxiliary 2-[(Dimethylamino)methyl]phenyl Ligand.

2007 ◽  
Vol 72 (8) ◽  
pp. 985-995 ◽  
Author(s):  
Martin Lamač ◽  
Ivana Císařová ◽  
Petr Štěpnička
Keyword(s):  
Carboxylic Acid ◽  
Carbon Atom ◽  
Single Crystal ◽  
Crystal Structures ◽  
Methyl Iodide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chiral Carbon ◽  
Hydrolysis Of ◽  
Methyl Phenyl

Treatment of racemic 1-(diphenylphosphanyl)-2-[(methoxycarbonyl)methyl]ferrocene successively with NaN(SiMe3)2 and methyl iodide affords the C-alkylated product, 1-(diphenylphosphanyl)-2-[1-(methoxycarbonyl)ethyl]ferrocene (6), as a mixture of diastereoisomers in ca. 10:1 ratio, from which the major (S,Rp/R,Sp)-diastereoisomer is easily isolated by crystallisation. (S,Rp/R,Sp)-6 reacts with [Pd(LNC)(MeCN)2]ClO4 (LNC = 2-[(dimethylamino-κN)- methyl]phenyl-κC1) to give the cationic bis-chelate complex (S,Rp/R,Sp)-[Pd(LNC)(6-κ2O,P)]- ClO4 (9). The structures of (S,Rp/R,Sp)-6 and 9 have been determined by single-crystal X-ray diffraction. Hydrolysis of ester 6 to the corresponding carboxylic acid proved to be difficult, being complicated by racemisation at the chiral carbon atom and oxidation of the phosphanyl group.

scholarly journals Synthesis, Characterization and Screening of Anti-tubercular activity of 2, 5-Disubstituted-1, 3, 4-Oxadiazole

2013 ◽  
Vol 1 (03) ◽  
pp. 12-19
Author(s):  
Alex Martin
Keyword(s):  
Spectral Analysis ◽  
Carboxylic Acid ◽  
Microwave Irradiation ◽  
Hydrazine Hydrate ◽  
Spectral Data ◽  
Acid Hydrazide ◽  
Mass Spectral Data ◽  
Furoic Acid ◽  
Mass Spectral ◽  
Phosphorous Oxychloride

The synthesis of 2-furyl-5-(substituted)-1,3,4-oxadiazoles was carried out by microwave irradiation of 2-furoic acid and ethanol followed by subsequent hydrazinolysis with hydrazine hydrate. Finally furan-2-acid hydrazide was treated with appropriate carboxylic acid in the presence of phosphorous oxychloride to produce title compounds. The structures of the newly synthesized compounds were established on the basis of spectral analysis such as IR, H1NMR and Mass spectral data. The synthesized compounds were screened for their anti-tubercular activity.

scholarly journals Expeditious synthesis of 1,3,4-oxadiazole derivatives via sydnones

2008 ◽  
Vol 73 (2) ◽  
pp. 131-138 ◽  
Author(s):  
Ravindra Kamble ◽  
B.S. Sudha ◽  
D.G. Bhadregowda
Keyword(s):  
Acetic Anhydride ◽  
Microwave Irradiation ◽  
Hydrazine Hydrate ◽  
Reaction Times ◽  
Elemental Analyses ◽  
Oxadiazole Derivatives

The clean cyclization of chalcones (1a-c/2a-c) with hydrazine hydrate under microwave irradiation afforded pyrazolines derivatised with sydnone (3d-i/4d-i), which underwent 1,3-dipolar cyclo-addition with acetic anhydride to form pyrazolines appended with 1,3,4-oxadiazoles (5g-l/6g-l). The newly synthesized compounds were confirmed by spectral and elemental analyses. In comparison to classical heating, the results indicate that microwave irradiation affords higher yields, shorter reaction times (4-12 min) and cleaner reactions.

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