518-05-8Relevant articles and documents
Mechanism of intramolecular catalysis in the hydrolysis of alkyl monoesters of 1,8-naphthalic acid
Souza, Bruno S.,Yunes, Santiago F.,Lima, Marcelo F.,Gesser, Jose C.,Sa, Marcus M.,Fiedler, Haidi D.,Nome, Faruk
, p. 6163 - 6170 (2011)
Hydrolysis of alkyl 1,8-naphthalic acid monoesters 1a-d is subject to highly efficient intramolecular nucleophilic catalysis by the neighboring COOH group. The reactivity for the COOH reaction depends on the leaving group pK a, with values of βLG of -0.50, consistent with a mechanism involving rate determining breakdown of tetrahedral addition intermediates. The release of the steric strain of the peri-substitiuents in the highly reactive alkyl 1,8-naphthalic acid monoesters is fundamental to understand the observed special reactivity in this intramolecular reaction. DFT calculations show how the proton transfers involved in the cleavage of the neutral ester can be catalyzed by solvent water, thus facilitating the departure of poor alkoxide leaving groups.
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Paillard,Duckert
, p. 773,774 (1933)
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Use of fourier transform infrared spectroscopy to follow the heterocumulene aided thermal dehydration of phthalic and naphthalic acids
Rigout, Muriel L. A.,Lewis, David M.
, p. 1405 - 1413 (2006)
Fourier transform infrared (FT-IR) spectroscopy has been successfully employed to follow the formation of phthalic anhydride and 1,8-naphthallc anhydride on heating their corresponding acids. The effects of three heterocumulenes, cyanamide, dicyandlamide, and sodium cyanate, on the temperature of formation of the anhydrides were also investigated using this method. It was found that the carbodlimides cyanamide and dicyandiamide dramatically lowered the temperature at which thermal dehydration of the acid led to anhydride formation. It was noted that cyanamide had a stronger catalytic effect than dicyandiamide, presumably due to the electron-withdrawing effect of the amidine group. Sodium cyanate was also found to promote the thermal dehydration of the acids to form the corresponding anhydrides. Under more severe conditions, phthalic acid anhydride formed is seen to react further, leading to the formation of phthalimide. The discrepancy between the products obtained with cyanamide and sodium cyanate leads to the conclusion that, unlike earlier claims, imide formation is not due to the reaction of the anhydride with the urea formed but with sodium cyanate itself. However, only the phthalic anhydride flve-membered ring system is sufficiently reactive towards the CNO- nucleophile to form the imide; the six-membered 1,8-naphthalic anhydride system does not react in this way.
Organocatalytic aerobic oxidative cleavage of cyclic 1,2-diketones
Gundala, Sivaji,Fagan, Claire-Louise,Delany, Eoghan G.,Connon, Stephen J.
supporting information, p. 1225 - 1228 (2013/07/19)
The first organocatalytic aerobic oxidative cleavage of cyclic 1,2-diketones is reported. The reaction occurs in either aqueous or alcoholic media and is promoted by a simple N-heterocyclic carbene catalyst derived from a 1,2,4-triazolium ion. No strong oxidants are required. The application of the process in a one-pot synthesis of a cyclic anhydride is also possible. Georg Thieme Verlag Stuttgart. New York.
Formation and decomposition of N-alkylnaphthalimides: Experimental evidences and ab initio description of the reaction pathways
De Barros, Teresa Cristina,Filho, Pedro Berci,Loos, Michel,Politi, Mario Jose,Chaimovich, Hernan,Cuccovia, Iolanda Midea
, p. 385 - 397 (2011/11/06)
The kinetics of hydrolysis of 1,8-N-butyl-naphthalimide (1,8-NBN) to 1,8-N-butyl-naphthalamide (1,8-NBAmide) and of 2,3-N-butyl-naphthalimide (2,3-NBN) to 2,3-N-butyl-naphthalamide (2,3-NBAmide), as well as the formation of the respective anhydrides from the amides were investigated in a wide acidity range. 1,8-NBN equilibrates with 1,8-NBAmide in mild alkali. Under the same conditions 2,3-NBN quantitatively yields 2,3-NBAmide. Over a wide range of acidities the reactions of the 1,8- and 2,3-N-butyl-naphthalamides (or imides) yield similar products but with widely different rates and at distinct pH's. Anhydride formation in acid was demonstrated for 1,8-NBAmide. The reactions mechanisms were rationalized in the manifold pathways of ab initio calculations. The differences in rates and pH ranges in the reactions of the 1,8- and 2,3-N-butyl-naphthalamides were attributed to differences in the stability of the tetrahedral intermediates in alkali as well as the relative stabilities of the five and six-membered ring intermediates. The rate of carboxylic acid assisted 1,8-N-Butyl-naphthalamide hydrolysis is one of the largest described for amide hydrolysis models. Copyright
