An acid-catalyzed Michael–aldol reaction

Reingold, I. David; Bowerman, Charles J.; John, Melissa; Walters, Robert S.; Daglen, Bevin C.; Butterfield, Anna M.; Gembický, Milan

doi:10.1016/j.tetlet.2005.12.115

Cited by 4 publications

(4 citation statements)

References 9 publications

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“…As can be seen in Figure b, conversion of the impurity and the yield of the condensation product have similar values. This fact agrees with the mechanism proposed for the condensation reaction between 2-cyclohexen-1-one and cyclohexanone, following a Michael addition mechanism that does not involve a dehydration step …”

Section: Resultssupporting

confidence: 90%

“…Hexanal and pentanal react by aldol condensation with cyclohexanone. On the other hand, 2-cyclohexenone and cyclohexanone could react by Michael addition . Condensation products have a higher boiling point than cyclohexanone and can be easily separated by distillation in further purification steps.…”

Section: Resultsmentioning

confidence: 99%

“…This fact agrees with the mechanism proposed for the condensation reaction between 2-cyclohexen-1-one and cyclohexanone, following a Michael addition mechanism that does not involve a dehydration step. 16 3.3. Kinetic Model.…”

Section: Influence Of Thementioning

confidence: 99%

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Kinetics of Alkali-Catalyzed Condensation of Impurities in the Cyclohexanone Purification Process

Lorenzo

Santos

Simón

et al. 2013

Ind. Eng. Chem. Res.

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In the cyclohexanone purification process, some impurities, such as pentanal, hexanal, and 2-cyclohexen-1-one, must be removed in order to ensure good quality of nylon fibers in the caprolactam polymerization step. To do this, an industrial common practice is to add a homogeneous basic catalyst (such as sodium hydroxide, NaOH) to promote the condensation of these impurities with cyclohexanone because the condensation products are easily separated by distillation. In this study, a kinetic model for the catalytic condensation of each impurity was developed, including variables such as temperature, impurity concentration, and catalyst concentration. In order to fulfill this purpose, runs were carried out in a batch reactor containing 70 g of cyclohexanone and different contents of impurities. NaOH was used as the catalyst (C NaOH values ranging from 2.5 to 30.0 mmol/kg). Runs were carried out by a nonisothermal procedure; the reaction temperature was changed from 298 to 423 K, and several temperature ramps were applied. All of the experiments were conducted at a pressure of 10 bar to ensure that all of the volatile compounds remained in the liquid phase. The products of the condensation reaction of each impurity with cyclohexanone were identified and quantified by gas chromatography/mass spectrometry. The reaction products found were as follows: 2-(1-pentenyl)cyclohexanone (A1) and 2-pentylidenecyclohexanone (A2), in which both isomers were lumped together and quantified as A; 2-(1-hexen-1-yl)cyclohexanone (B1) and 2-hexylidenecyclohexanone (B2), in which these isomers were lumped together and quantified as B; [1,1′-bicyclohexyl]-2,2′-dione (C1) and [1,1′-bicyclohexyl]-2,3′-dione (C2), in which both were lumped together as C. The kinetic parameters were estimated by data fitting. The estimated activation energies of impurity elimination were 3.47 kJ/mol for pentanal, 3.99 kJ/mol for hexanal, and 24.23 kJ/mol for 2-cyclohexen-1-one. This kinetic model reproduced the experimental results quite well. Moreover, experimental data from isothermal experiments were also reasonably well predicted with the model.

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Section: Resultssupporting

confidence: 90%

Section: Resultsmentioning

confidence: 99%

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Kinetics of Alkali-Catalyzed Condensation of Impurities in the Cyclohexanone Purification Process

Lorenzo

Santos

Simón

et al. 2013

Ind. Eng. Chem. Res.

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“…Reaction between CX-ENONE and cyclohexanone is promoted using a basic catalyst as shown in Scheme . The presence of sodium hydroxide in the reaction media catalyzes the Michael addition , reaction between CX-ENONE and cyclohexanone. As can be seen in Scheme , two isomers are generated.…”

Section: Introductionmentioning

confidence: 99%

Optimization-Based Design of a Reactive Distillation Column for the Purification Process of Cyclohexanone Using Rigorous Simulation Model and Validated Using an Experimental Packed Column

Lorenzo

Santos

Pérez-Galván

et al. 2018

Ind. Eng. Chem. Res.

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Table S1. Properties and abbreviations of compounds used in the RD model 1. Component Abbreviation Formula MW CAS Tb/K Cyclohexanone CX-ONE C6H10O 98 108-94-1 428 2-Cyclohexen-1-one CX-ENONE C6H8O 96 930-68-7 443 2-(1-cyclohexen-1-yl)cyclohexanone D2 a C12H18O 178 1502-22-3 538.15 2-cyclohexylidencyclohexanone D3 a C12H18O 178 1011-12-7 538.15 [1,1'-bicyclohexyl]-2,2'-dione C1 b C12H18O2 194 32673-76-0 601±25.0 [1,1'-bicyclohexyl]-2,3'-dione C2 b C12H18O2 194 88974-62-3 601±25.0 Cyclohexanol CX-OL C6H12O 100 108-93-0 434 a Lumped as DIMER with the properties of 2-(1-cyclohexen-1-yl)cyclohexanone. b Lumped as DIONE with the properties of [1,1'-bicyclohexyl]-2,2'-dione.

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Reactions of Aldehydes and Ketones and their Derivatives

Murray

2010

Organic Reaction Mechanisms · 2006

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An acid-catalyzed Michael–aldol reaction

Cited by 4 publications

References 9 publications

Kinetics of Alkali-Catalyzed Condensation of Impurities in the Cyclohexanone Purification Process

Kinetics of Alkali-Catalyzed Condensation of Impurities in the Cyclohexanone Purification Process

Optimization-Based Design of a Reactive Distillation Column for the Purification Process of Cyclohexanone Using Rigorous Simulation Model and Validated Using an Experimental Packed Column

Reactions of Aldehydes and Ketones and their Derivatives

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