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Formation and decomposition of N ‐alkylnaphthalimides: experimental evidences and ab initio description of the reaction pathways
Author(s) -
de Barros Teresa Cristina,
Filho Pedro Berci,
Loos Michel,
Politi Mario José,
Chaimovich Hernan,
Cuccovia Iolanda Midea
Publication year - 2011
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.1768
Subject(s) - chemistry , hydrolysis , amide , ab initio , alkali metal , yield (engineering) , decomposition , reactivity (psychology) , tetrahedral carbonyl addition compound , kinetics , reaction mechanism , medicinal chemistry , computational chemistry , organic chemistry , catalysis , nucleophile , thermodynamics , pathology , quantum mechanics , medicine , physics , alternative medicine
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 © 2010 John Wiley & Sons, Ltd.