scholarly journals Experimental Design-Based Response Surface Methodology Optimization for Synthesis of β-Mercapto Carbonyl Derivatives as Antimycobacterial Drugs Catalyzed by Calcium Pyrophosphate

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Younes Abrouki ◽  
Abdelkader Anouzla ◽  
Hayat Loukili ◽  
Jamal Bennazha ◽  
Rabiaâ Lotfi ◽  
...  

A simple protocol for the efficient preparation of β-mercapto carbonyl derivatives as antimycobacterial drugs has been achieved via Thia-Michael reaction between chalcones derivatives and thiols in the presence of calcium pyrophosphate as a heterogeneous catalyst under mild reaction conditions. The central composite design was used to design an experimental program to provide data to model the effects of various factors on reaction yield (Y). The variables chosen were catalyst weight X1, reaction time X2, and solvent volume X3. The mathematical relationship of reaction yield on the three significant independent variables can be approximated by a nonlinear polynomial model. Predicted values were found to be in good agreement with experimental values. The optimum reaction conditions for reaction model (chalcone and thiophenol) obtained by response surface were applied to other substrates. This procedure provides several advantages such as high yield, clean product formation, and short reaction time.

2019 ◽  
Vol 31 (4) ◽  
pp. 829-833
Author(s):  
D.S. Bhagat ◽  
S.G. Pande ◽  
M.V. Katariya ◽  
R.P. Pawar ◽  
P.S. Kendrekar

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.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Feray Aydogan ◽  
Cigdem Yolacan

A new procedure to synthesize the N-substituted pyrrole derivatives by Clauson Kaas reaction catalyzed by acidic ionic liquid under microwave irradiation was developed. This procedure provides several advantages such as high yield, clean product formation, and short reaction time.


2017 ◽  
Vol 2 (1) ◽  
pp. 1-10 ◽  
Author(s):  
O. S. Aliozo ◽  
L. N. Emembolu ◽  
O. D. Onukwuli

Abstract In this research work, melon oil was used as feedstock for methyl ester production. The research was aimed at optimizing the reaction conditions for methyl ester yield from the oil. Response surface methodology (RSM), based on a five level, four variable central composite designs (CCD)was used to optimize and statistically analyze the interaction effect of the process parameter during the biodiesel production processes. A total of 30 experiments were conducted to study the effect of methanol to oil molar ratio, catalyst weight, temperature and reaction time. The optimal yield of biodiesel from melon oil was found to be 94.9% under the following reaction conditions: catalyst weight - 0.8%, methanol to oil molar ratio - 6:1, temperature - 55°C and reaction time of 60mins. The quality of methyl ester produced at these conditions was within the American Society for Testing and Materials (ASTM D6751) specification.


2015 ◽  
Vol 10 (2) ◽  
pp. 123-133 ◽  
Author(s):  
Mohammadreza Sabzimaleki ◽  
Barat Ghobadian ◽  
Mohsen Mazloom Farsibaf ◽  
Gholamhassan Najafi ◽  
Masoud Dehghani Soufi ◽  
...  

Abstract Production of biodiesel from castor oil (CO) using ultrasound-assisted has been investigated in this study. The objective of the present work was therefore to determine the relationship between various important parameters of the alkaline-catalyzed transesterification process to obtain a high reaction yield in a short time. The response surface methodology (RSM) was used to statistically analyze and optimize the operating parameters of the process. A central composite design (CCD) was approved to study the effects of the reaction time, the methanol to oil molar ratio, the ultrasonic cycle and the ultrasonic amplitude on reaction yield. The optimum conditions for alkaline-catalyzed transesterification of CO was found to be a reaction time of 540 s, methanol to oil molar ratio of 8.15:1,ultrasonic cycle of 0.73% and ultrasonic amplitude 64.34%. By exerting the calculated optimum condition in the process, the reaction yield reached 87.0494%. The results from the RSM analysis indicated that the reaction time has the most significant effect on the reaction yield.


2020 ◽  
Vol 17 (7) ◽  
pp. 517-522
Author(s):  
Azizollah Habibi ◽  
Sahar Khosravi ◽  
Seyyed M. Shahcheragh ◽  
Mohd B. Abdul Rahman

In the current study, a green, one-pot, three-component reaction was performed to prepare novel N-substituted 5-amino-1,3,4-thiadiazole derivatives. The thiadiazoles were obtained from the reaction of a ketene S,S-acetal of Meldrum’s acid or barbituric acid (as key intermediates), hydrazine, and isothiocyanate. The key advantages of this manner include environmentally safe reactions, high yield, appropriate reaction time, simple reaction conditions, and use of a green reaction solvent. The structure of thiadiazoles was determined based on the spectroscopic data.


2004 ◽  
Vol 22 (SI - Chem. Reactions in Foods V) ◽  
pp. S235-2S37
Author(s):  
L. Sihelniková ◽  
A. Synytsya ◽  
J. Čopíková

Pectins are plant polysaccharides that are widely used in food industry. Chemical modification of pectins influences their technological properties. Amidated pectins are important pectin derivatives with good gelling properties at low-sugar conditions. The common method of pectin amidation is ammonolysis of methyl ester groups of highly methoxylated (HM) pectins in heterogeneous reaction with ammonia in methanol. Aminodealkoxylation (aminolysis) of HM pectin with primary amines leads to the formation of N-alkylpectinamides. The reaction yield of aminolysis depends on reaction time, temperature and the pectin/alkylamine ratio. The reaction of HM citrus pectin (type XSS, Danisco) with five chosen n-alkylamines (n-butylamine, n-hexylamine, n-octylamine, n-dodecylamine and n-octadecylamine) was carried out in N,N-dimethylformamide at 20°C (n-butylamine, n-hexylamine, n-octylamine) and at 50°C (all the amines) for 1–9 days. Obtained results can be applied to prepare N-alkylpectinamides of predicted DA varying the reaction time at the same reaction conditions (temperature, pectin/alkylamine ratio).


2012 ◽  
Vol 602-604 ◽  
pp. 1373-1378
Author(s):  
Jing Liang ◽  
Zhen Xing Cheng ◽  
Lian Yuan Wang ◽  
Hai Yan Zhu ◽  
Shi Gao ◽  
...  

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.


Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 889
Author(s):  
Hao Peng ◽  
Jing Guo ◽  
Hongzhi Qiu ◽  
Caiqiong Wang ◽  
Chenyu Zhang ◽  
...  

A highly efficient reduction process of Cr (VI) with biochar was conducted in this paper. The results showed that nearly 100% Cr (VI) was reduced at selected reaction conditions: Dosage of biochar at m (C)/m(Cr) = 3.0, reaction temperature of 90 °C, reaction time of60 min, and concentration of H2SO4 of 20 g/L. The reduction kinetics analysis demonstrated that the reduction of Cr (VI) fitted well with the pseudo-first-order model and the apparent activation energy was calculated to be 40.24 kJ/mol. Response surface methodology confirmed that all of the experimental parameters had a positive effect on the reduction of Cr (VI). The influence of each parameter on the reduction process followed the order: Dosage of biochar>concentration of H2SO4>reaction temperature >reaction time. This paper provides a versatile strategy for the treatment of wastewater containing Cr (VI) and shows a bright tomorrow for wastewater treatment.


Synthesis ◽  
2019 ◽  
Vol 51 (18) ◽  
pp. 3443-3450 ◽  
Author(s):  
Anoop S. Singh ◽  
Anand K. Agrahari ◽  
Sumit K. Singh ◽  
Mangal S. Yadav ◽  
Vinod K. Tiwari

The good leaving tendency of the benzotriazole moiety has been exploited for the synthesis of symmetric, unsymmetric, N-acyl, and cyclic ureas in good yields from N-acylbenzotriazoles by treating the latter with various amines in the presence of TMSN3/Et3N in a sealed tube. The salient features of the devised protocol includes the high-yield, mild, metal-free, one-pot reaction conditions, and short reaction time. Furthermore, in many cases, no column chromatography is required for the purification.


Author(s):  
Hao Peng ◽  
Jing Guo

A highly efficient reduction process of Cr (VI) with biochar was conducted in this paper. The results showed that nearly 100% Cr (VI) was reduced at selected reaction conditions: the dosage of biochar at m (C)/m(Cr) = 3.0, reaction temperature of 90 ℃, reaction time at 60 min and concentration of H2SO4 of 20 g/L, respectively. The reduction kinetics analysis demonstrated that the reduction of Cr (VI) fitted well with the pseudo-first-order model and the apparent activation energy was calculated to 40.24 kJ/mol. Response surface methodology confirmed that all the experimental parameters had positive effect on the reduction of Cr (VI). The influence of each parameter on the reduction process followed the order: dosage of biochar> Concentration of H2SO4 > Reaction Temperature > Reaction Time. This paper provided a versatile strategy for treatment of wastewater containing Cr (VI) and showed a bright tomorrow for wastewater treatment.


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