scholarly journals Friedel-Crafts acylation of 2-methoxynaphthalene with acetic anhydride catalyzed by phosphotungstic acid in ionic liquid

2019 ◽  
Vol 51 (2) ◽  
pp. 289-295
Author(s):  
Y. Guo ◽  
J. Sun ◽  
F. Guo ◽  
Yu. He ◽  
P. Chen
Keyword(s):  
Ionic Liquid ◽  
Reaction Time ◽  
Acetic Anhydride ◽  
Catalytic System ◽  
Phosphotungstic Acid ◽  
Significant Loss ◽  
Good Stability ◽  
Optimal Conditions ◽  
Reaction Conditions

The Friedel-Crafts acylation of 2-methoxynaphthalene (2-MN) with acetic anhydride (AA) was carried out in the ionic liquid (IL) butylpyridinium tetrafluoroborate ([BPy]BF4) using phosphotungstic acid (H3PW12O40) as the catalyst. The [BPy]BF4-mediated 2-MN acylation displays good conversion and selectivity towards 1-acyl-2-methoxynaphthalene (1-AC-2-MN), with 70.4% conversion of 2-MN and 96.4% selectivity to 1-AC-2-MN obtained under the optimal conditions. Owing to the rearrangement of 1-AC-2-MN, 6-acyl-2-methoxynaphthalene (6-AC-2-MN) can be detected after 1 h of reaction time, with the highest 6-AC-2-MN yield of 11.3% obtained under the examined reaction conditions. The system can be recycled and reused at least 6 times without significant loss of activity, indicating the good stability of the H3PW12O40/[BPy]BF4 catalytic system.

scholarly journals LiHSO4/SiO2as a New, Efficient and Reusable Catalytic System for the Chemoselective Conversion of Aldehydes to Acylals under Solvent-Free Conditions

2009 ◽  
Vol 6 (s1) ◽  
pp. S390-S396 ◽  
Author(s):  
Abdolkarim Zare ◽  
Alireza Hasaninejad ◽  
Esmael Rostami ◽  
Ahmad Reza Moosavi-Zare ◽  
Maria Merajoddin ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Acetic Anhydride ◽  
Catalytic System ◽  
Catalytic Amount ◽  
Significant Loss ◽  
Solvent Free ◽  
Reaction Conditions ◽  
Highly Efficient ◽  
Solvent Free Conditions

A highly efficient, green and expeditious solvent-free method is described for the chemoselective conversion of aldehydes to the corresponding acylals in excellent yields, using acetic anhydride in the presence of catalytic amount (20 mol%) of silica-supported LiHSO4. Ketones does not react under these reaction conditions. LiHSO4/SiO2can be recovered and reused without any significant loss of its catalytic activity.

Efficient Copper-Catalyzed Synthesis of Substituted Pyrazoles at Room Temperature

Synlett ◽  
2018 ◽  
Vol 29 (20) ◽  
pp. 2689-2692 ◽  
Author(s):  
Haifeng Wang ◽  
Xiangli Sun ◽  
Shuangling Zhang ◽  
Guanglu Liu ◽  
Chunjie Wang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Catalytic System ◽  
Efficient Method ◽  
Room Temperature ◽  
Copper Catalyst ◽  
Condensation Reaction ◽  
Reaction Conditions ◽  
Short Reaction Time ◽  
Acid Catalyzed ◽  
Substituted Pyrazoles

An efficient method for the synthesis of pyrazoles through a copper-catalyzed condensation reaction has been developed. The new catalytic system not only maintained a broad substrate scope but was also active under acid-free reaction conditions, overcoming the conventional requirement for an acid-catalyzed system. Furthermore, the copper catalyst enabled this reaction to be performed at room temperature and in a short reaction time.

scholarly journals Microwave Assisted One Pot Synthesis of 3,4-Dihydropyrano[c]chromene Derivatives using [Emim]OH Ionic Liquid as Novel Catalyst

2019 ◽  
Vol 31 (4) ◽  
pp. 829-833
Author(s):  
D.S. Bhagat ◽  
S.G. Pande ◽  
M.V. Katariya ◽  
R.P. Pawar ◽  
P.S. Kendrekar
Keyword(s):  
Ionic Liquid ◽  
Reaction Time ◽  
High Yield ◽  
Reaction Conditions ◽  
One Pot ◽  
Short Reaction Time ◽  
Aryl Aldehydes ◽  
Microwave Assisted ◽  
Novel Catalyst ◽  
Work Up

One-pot efficient protocol to the synthesis of 2-amino-5-oxo-4,5-dihydropyrano(3,2-c)chromene-3-carbonitrile derivatives via condensation of various aryl aldehydes, dicyanomethane and 4-hydroxycoumarin in presence of Emim hydroxide as an excellent homogeneous liquid catalyst. The key advantages of this methodology are mild reaction conditions, novel catalyst, short reaction time, eco-friendly, easy work-up procedure and high yield of isolation of derivatives.

scholarly journals An Improved Protocol for the Aldehyde Olefination Reaction Using (bmim) () as Reaction Medium

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Vivek Srivastava
Keyword(s):  
Ionic Liquid ◽  
Reaction Time ◽  
Catalytic System ◽  
Good Yield ◽  
Reaction Medium ◽  
Liquid Media

[Ru(COD)Cl2]/CuCl2·2H2O/LiCl catalytic system works efficiently in ionic liquid media for aldehyde olefination reaction. It offers good yield and selectivity with the added advantage of 5 times recyclability for [Ru(COD)Cl2] /CuCl2·2H2O/LiCl catalytic system. We also successfully reduced the reaction time from 12 hours to 9 hours for the aldehyde olefination reaction.

Rapid synthesis of homoallylic alcohol from aldehyde with allyltributylstannane under solvent-free conditions

2012 ◽  
Vol 90 (2) ◽  
pp. 167-172 ◽  
Author(s):  
Pranjal P. Bora ◽  
H. Atoholi Sema ◽  
Barisha Wahlang ◽  
Ghanashyam Bez
Keyword(s):  
Reaction Time ◽  
Phosphotungstic Acid ◽  
Catalytic Amount ◽  
Solvent Free ◽  
Reaction Conditions ◽  
Rapid Synthesis ◽  
Short Reaction Time ◽  
Solvent Free Conditions ◽  
Solvent Free Reaction

A catalytic amount (2 mol %) of phosphotungstic acid (PTA) is sufficient to synthesize homoallylic alcohol in excellent yields from aldehyde with allyltributylstannane upon grinding under solvent-free reaction conditions. Easy handling, very short reaction time, solvent-free reaction conditions, and aqueous workup free isolation protocol may make our method very useful for synthetic chemists.

Synthesis of Diethyl Carbonate from Ethyl Carbamate and Ethanol with Acid as Catalyst

2013 ◽  
Vol 821-822 ◽  
pp. 1081-1084 ◽  
Author(s):  
Xian Ye Qin ◽  
Biao Liu ◽  
Bing Han ◽  
Wen Bo Zhao ◽  
Shui Sheng Wu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Ethyl Carbamate ◽  
Diethyl Carbonate ◽  
Bronsted Acid ◽  
Optimal Conditions ◽  
Reaction Conditions ◽  
Brönsted Acid ◽  
Pyrophosphoric Acid

The catalytic activity of many Lewis and Bronsted acid for the synthesis of diethyl carbonate (DEC) from ethyl carbamate (EC) and ethanol was evaluated in a bath reactor. Pyrophosphoric acid (H4P7O2) which showed the best activity was selected to further investigate the effect of reaction conditions, such as reaction temperature, catalyst dose and reaction time, on the yield of DEC. Under the optimal conditions, DEC yield can reach 29.1%.

Synthesis of Several Sugar Acetates and their Structures Characterization

2012 ◽  
Vol 602-604 ◽  
pp. 1373-1378
Author(s):  
Jing Liang ◽  
Zhen Xing Cheng ◽  
Lian Yuan Wang ◽  
Hai Yan Zhu ◽  
Shi Gao ◽  
...  
Keyword(s):  
Reaction Time ◽  
Acetic Anhydride ◽  
Reaction Temperature ◽  
Soluble Starch ◽  
Degree Of Substitution ◽  
High Yield ◽  
Reaction Conditions ◽  
Alkaline Catalyst ◽  
Acetate Esters ◽  
Acidic Catalyst

Several acetate esters were synthesized by reacting sugars, i.e. glucose, soluble starch, and dextrin, with acetic anhydride in the presence of some catalysts. Their structures were confirmed by IR and MS. Influences of the reaction conditions, such as catalyst and its dosage, reaction time, reaction temperature and acetic anhydride content, on the value of degree of substitution (DS) and the yield for starch acetates had also been investigated. Results showed that glucose could be easily completely acetylated; acidic catalyst tended to form a configuration of α-glucose penta-acetate (α-GPA), while alkaline catalyst β-GPA. However, soluble starch and dextrin were more difficult to be completely substituted by acetic anhydride. The DS value of soluble starch was below 2; for dextrin, its DS value could reach 2.3, close to the theoretical value of 3. An appropriate reaction temperature and reaction time were important for high yield as well as high DS value.

Study on the Chemical Modification of Cellulose in Ionic Liquid with Maleic Anhydride

2012 ◽  
Vol 581-582 ◽  
pp. 287-291 ◽  
Author(s):  
Hai Feng Li ◽  
Huan Li ◽  
Xuan Zhong ◽  
Xin Da Li ◽  
Magdi E. Gibril ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Infrared Spectroscopy ◽  
Reaction Time ◽  
Thermogravimetric Analysis ◽  
Maleic Anhydride ◽  
Chemical Modification ◽  
Cotton Cellulose ◽  
Optimal Conditions ◽  
Mass Ratio

Dissolution and regeneration of cotton cellulose using ionic liquids as solvent was investigated. In this paper, modification of celluloses with maleic anhydride (MA) was carried out in ionic liquid,1-allyl-3-methylimidazolium chloride(AmimCl).The maleylation celluloses with degrees of substitution (DS) between 0.85and 1.46 were accessible in IL. The effects of reaction time, temperature and mass ratio of the MA in cellulose were investigated. These maleylation celluloses were characterized by infrared spectroscopy, thermogravimetric analysis (TGA). Experiments showed that the optimal conditions for grafting were: mass ratio of maleic anhydride and cotton cellulose 0.8; reaction time of 90 min; temperature of 80 °C.

scholarly journals Cs2CO3/[bmim]Br as an Efficient, Green, and Reusable Catalytic System for the Synthesis of N-Alkyl Derivatives of Phthalimide under Mild Conditions

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
Alireza Hasaninejad ◽  
Abdolkarim Zare ◽  
Ahmad Reza Moosavi-Zare ◽  
Fatemeh Khedri ◽  
Rahimeh Rahimi ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Catalytic System ◽  
Reaction Times ◽  
Catalytic Amount ◽  
Conjugate Addition ◽  
Reaction Conditions ◽  
Mild Conditions ◽  
Alkyl Derivatives ◽  
High Yields ◽  
Derivatives Of

Aza-conjugate addition of phthalimide to α,β-unsaturated esters efficiently achieves in the presence of catalytic amount of Cs2CO3 and ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br) under mild reaction conditions (70°C) to afford N-alkyl phthalimides in high yields and relatively short reaction times.

Silica Gel-Supported Phosphotungstic Acid (PTA) Catalysed Acylation of Alcohols and Phenols with Acetic Anhydride under Mild Reaction Conditions

2003 ◽  
Vol 2003 (7) ◽  
pp. 412-414 ◽  
Author(s):  
Tong-Shou Jin ◽  
Jin-Chong Xiao ◽  
Zhen-Hua Wang ◽  
Tong-Shuang Li
Keyword(s):  
Acetic Anhydride ◽  
Silica Gel ◽  
Room Temperature ◽  
Phosphotungstic Acid ◽  
Reaction Conditions

Phosphotungstic acid, which is commercially available, practically and efficiently catalyses the acylation of a series of alcohols and phenols with acetic anhydride at room temperature or at refluxing temperature.

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