621-76-1Relevant academic research and scientific papers
Green preparing orthoformate cleaning process
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Paragraph 0050; 0052; 0053, (2016/10/07)
The invention provides a green process for preparing orthoformate. A hydrogen chloride alcohol solution is prepared from a byproduct hydrogen chloride tail gas of the chlorine-related synthesis industry and then is slowly added into a reaction system, so that loss caused by escape of hydrocyanic acid is reduced, the yield is increased, great equipment corrosion caused by the byproduct hydrochloric acid prepared by the companies is avoided, the economic additional value of the byproduct hydrogen chloride is greatly increased, three wastes are avoided, the byproduct only comprises ammonium chloride, resources are reasonably utilized, and the green process for preparing the orthoformate is an environment-friendly production process and has a good social benefit.
Synthesis and Application of α,ω-Bis(dialkylamino)oligooxaalkanes and Their Analogs as Phase-Transfer Catalysts in Heterogeneous Synthesis of Trialkyl Orthoformates
Shtamburg, V. G.,Skobelev, O. L.,Grinev, V. M.,Dmitrienko, A. D.,Pleshkova, A. P.,Pritykin, L. M.
, p. 609 - 612 (2007/10/03)
α,ω-Bis(dialkylamino)oligooxaalkanes, 1,8-bis(alkoxyamino)-3,6-dioxaoctanes, and 1,8-bis(diethylamino)-3,6-dioxaoctane N,N'-dioxide are efficient phase-transfer catalysts, the use of which ensures preparation in high yields of trialkyl orthoformates from chloroform and primary alcohols in the heterogeneous systems CH2Cl2-solid alkali metal hydroxide.
Hydration of acylimidazoles: tetrahedral intermediates in acylimidazole hydrolysis and nucleophilic attack by imidazole on esters. The question of concerted mechanisms for acyl transfers
Guthrie, J. Peter,Pike, David C.
, p. 1951 - 1970 (2007/10/02)
Heats of hydrolysis have been measured for three acylimidazole acetals.From these results free energies of formation in aqueous solution have been calculated for the acetals and the corresponding tetrahedral intermediates.Having free energies of formation for the tetrahedral intermediates allows a detailed analysis of the energetics of both the unobservable nucleophilic reaction of imidazole with ethyl acetate and also the observable reaction of imidazole with p-nitropehnyl acetate. pKa values of 1-(3-aminopropyl)-imidazole and 1-(2-aminoethyl)-imidazole have been determined to allow calculation of the ?* value for the imidazolyl substituent .The dependence of imidazole pKa values on the electron-withdrawing properties of the 1-substituent was also determined.There is a linear free energy relation between the free energy change for replacement of OH in a carbonyl hydrate by imidazolyl and the sum of the ?* values for the other substituents.The implications of these results for the question of concerted versus stepwise mechanism for the reaction of imidazole with aryl acetates have been examined.An equilibrium constant has been calculated for the addition of imidazole to p-nitrophenyl acetate.A simple extension of Marcus theory allows the free energy surface for a three-dimensional reaction coordinate diagram to be calculated using the energy levels of the tetrahedral intermediate determined in this work, the energy level of the acylium ion derived from literature data, and intrinsic barriers for the edge reactions.It is shown, that the reaction of imidazole with p-nitrophenyl acetate probably follows a concerted path.General conclusions from this theory of concerted reaction are discussed.
On the Mechanism of Acetalization Reactions with Carboxamide-Dialkyl Sulfate Adducts; a New Method of Preparation of Orthocarboxylic Esters and of Cleavage of Carboxamides.
Kantlehner, Willi,Gutbrod, Heinz-Dieter
, p. 1677 - 1688 (2007/10/02)
It is shown that the efficiency of carboxamide-dialkyl-sulfate adducts in acetalization reactions depends on their alkylation ability.A mechanism of acetal formation using orthoformates as acetalization reagents is proposed.Alcoholysis of carboxamide-dialkyl sulfate adducts 1b, 11, 13 affords orthocarboxylic esters.Carboxamides and carboxmorpholides react with dimethyl sulfate/methanol to give methyl esters.
