Investigation of the kinetics of the synthesis of methylheptenone under conditions of homogeneous acid catalysis

The cyclization kinetics of N-(2-methylcarbonylphenyl)-N’-methylsulfonamide (IIb) into 3-methyl-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide (Ib) has been studied in ethanolamine, morpholine, and butylamine buffers and in potassium hydroxide solution. The cyclization is subject to general base and general acid catalysis. The value of the Bronsted coefficient β is about 0.1, which indicates that splitting off of the proton from negatively charged tetrahedral intermediate represents the rate-limiting and thermodynamically favourable step. In the solutions of potassium hydroxide the cyclization of dianion of the starting ester IIb probably becomes the rate-limiting step.

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Kinetics of the Acid Catalysis of the Hydration of Fumaric Acid to Malic Acid

The Journal of Physical Chemistry ◽

10.1021/j150558a017 ◽

1957 ◽

Vol 61 (12) ◽

pp. 1637-1640 ◽

Cited By ~ 10

Author(s):

Lee T. Rozelle ◽

Robert A. Alberty

Keyword(s):

Fumaric Acid ◽

Malic Acid ◽

Acid Catalysis ◽

Kinetics Of

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The kinetics of the interaction of singlet excited state methyl-2-naphthoate with sulfuric acid; search for excited state acid catalysis

Journal of Photochemistry and Photobiology A Chemistry ◽

10.1016/1010-6030(93)80114-o ◽

1993 ◽

Vol 74 (2-3) ◽

pp. 171-180 ◽

Cited By ~ 2

Author(s):

Yuan L. Chow ◽

Carl I. Johansson

Keyword(s):

Excited State ◽

Sulfuric Acid ◽

Acid Catalysis ◽

Singlet Excited State ◽

Kinetics Of

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FATTY ACID ESTERIFICATION: EFFECTS OF UNSATURATION AND SYNTHESIS WITH THERMAL HEATING VIA ULTRASON AND MICROWAVES

Periódico Tchê Química ◽

10.52571/ptq.v15.n30.2018.450_periodico30_pgs_447_462.pdf ◽

2018 ◽

Vol 15 (30) ◽

pp. 447-462

Author(s):

M. C. de M. SOUZA ◽

L. DI SOUZA ◽

V. P. da S. Caldeira ◽

A. G. D. SANTOS ◽

B. ADILSON

Keyword(s):

Fatty Acids ◽

Oleic Acid ◽

Fatty Acid ◽

Energy Demand ◽

Fossil Fuels ◽

Acid Catalysis ◽

Thermal Heating ◽

Ultrasonic Methods ◽

Homogeneous Acid ◽

Acid Esterification

With the increasing selective energy demand, fossil fuels are becoming scarce and environmentally incorrect, a viable alternative to this problem being the production of biodiesel. However, the esterification and transesterification reactions used are slow, expensive and ecologically incorrect because they produce polluting waste. Thus, it is necessary to develop techniques, reagents and equipment that make them fast, cheap and environmentally friendly. This work evaluated the performance of the thermal heating, microwave and ultrasonic methods in the esterification efficiency of oleic and stearic fatty acids via homogeneous acid catalysis. The efficiency of the reaction was certificated with the variables: time, yield and conversion and the biodiesel characterization were done with TG / DTG, FTIR and NMR. Conversions were determined by TG and 1H NMR and the yield by gravimetry. The results showed conversion with all methods with differences in the analyzed variables. The yields decrease in the microwave order (52%) conduction (33%) ultrasound (30%) for reactions with oleic acid and are practically the same (22, 22 and 20), independently of the stearic acid. Among the methods used, the most efficient is the microwave, because it has a higher yield in the case of oleic acid and reducing the reaction time.

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Mechanism and theory of d-glucopyranose homogeneous acid catalysis in the aqueous solution phase

Physical Chemistry Chemical Physics ◽

10.1039/c8cp07224h ◽

2019 ◽

Vol 21 (32) ◽

pp. 17993-18011 ◽

Cited By ~ 1

Author(s):

Manik Kumer Ghosh ◽

Mícheál Séamus Howard ◽

Karla Dussan ◽

Stephen Dooley

Keyword(s):

Aqueous Solution ◽

Acid Hydrolysis ◽

Acid Catalysis ◽

Theoretical Study ◽

Solution Phase ◽

Homogeneous Acid ◽

Hydrolysis Of

Theoretical study of the mechanism of acid hydrolysis of β-d-glucopyranose in the aqueous solution.

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ChemInform Abstract: KINETICS OF THE STEPWISE OXIDATION OF MANGANESE(II) BY PEROXODIPHOSPHATE (PDP) IN AQUEOUS PERCHLORIC ACID. CATALYSIS BY SILVER(I)

Chemischer Informationsdienst ◽

10.1002/chin.198501029 ◽

1985 ◽

Vol 16 (1) ◽

Author(s):

K. J. M. RAO ◽

A. S. P. VITTAL ◽

P. V. K. RAO

Keyword(s):

Perchloric Acid ◽

Acid Catalysis ◽

Aqueous Perchloric Acid ◽

Kinetics Of

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Reaction kinetics of 1,2-diaminobenzene with ethyl 2-oxopropanoate and 2,3-butanedione

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19883154 ◽

1988 ◽

Vol 53 (12) ◽

pp. 3154-3163 ◽

Cited By ~ 1

Author(s):

Jiří Klicnar ◽

Jaromír Mindl ◽

Ivana Obořilová ◽

Jaroslav Petříček ◽

Vojeslav Štěrba

Keyword(s):

Reaction Kinetics ◽

Acid Catalysis ◽

Reaction Pathway ◽

Hydroxide Ion ◽

Tetrahedral Intermediate ◽

Rate Limiting Step ◽

Limiting Step ◽

General Acid ◽

Rate Limiting ◽

Kinetics Of

The reaction of 1,2-diaminobenzene with 2,3-butanedione is subject to general acid catalysis in acetate and phosphate buffers (pH 4-7). The rate-limiting step of formation of 2,3-dimethylquinoxaline consists in the protonation of dipolar tetrahedral intermediate. In the case of the reaction of 1,2-diaminobenzene with ethyl 2-oxopropanoate, the dehydration of carbinolamine gradually becomes rate-limiting with increasing pH in acetate buffers, whereas in phosphate buffers a new reaction pathway makes itself felt, viz. the formation of amide catalyzed by the basic buffer component and by hydroxide ion.

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