102245-28-3Relevant articles and documents
Water solvent method for esterification and amide formation between acid chlorides and alcohols promoted by combined catalytic amines: Synergy between N-methylimidazole and N,N,N′,N′-tetramethylethylenediamine (TMEDA)
Nakatsuji, Hidefumi,Morita, Jun-Ichi,Misaki, Tomonori,Tanabe, Yoo
, p. 2057 - 2062 (2006)
An efficient method for esterification between acid chlorides and alcohols in water as solvent has been developed by combining the catalytic amines, N-methylimidazole and N,N,N′,N′-tetramethylethylenediamine (TMEDA). The present Schotten-Baumann-type reaction was performed by maintaining the pH at around 11.5 using a pH controller to prevent the decomposition of acid chlorides and/or esters and to facilitate the condensation. The choice of catalysts (0.1 equiv.) was crucial: the combined use of N-methylimidazole and TMEDA exhibited a dramatic synergistic effect. The catalytic amines have two different roles: (i) N-methylimidazole forms highly reactive ammonium intermediates with acid chlorides and (ii) TMEDA acts as an effective HCl binder. The production of these intermediates was rationally supported by a careful 1H NMR monitoring study. Related amide formation was also achieved between acid chlorides and primary or secondary amines, including less nucleophilic or water-soluble amines such as 2-(or 4-)chloroaniline, the Weinreb N-methoxyamine, and 2,2-dimethoxyethanamine.
Mild, powerful, and robust methods for esterification, amide formation, and thioesterification between acid chlorides and alcohols, amines, thiols, respectively
Nakatsuji, Hidefumi,Morimoto, Mami,Misaki, Tomonori,Tanabe, Yoo
, p. 12071 - 12080 (2008/03/13)
We developed two efficient practical methods for esterification, amide formation, and thioesterification between acid chlorides and alcohols, amines, thiols, respectively. The present mild and robust reaction was performed by two separate methods both by combining cheap and readily available amines, N-methylimidazole, and N,N,N′,N′-tetramethylethylenediamine (TMEDA). Method A uses catalytic N-methylimidazole and TMEDA with an equimolar amount of K2CO3, whereas Method B uses equimolar amounts of N-methylimidazole and TMEDA. The salient features are as follows. (i) With regard to reactivity, Method B was superior to Method A for esterification and thioesterification, whereas cost-effective Method A was superior to Method B for amide formation. (ii) Amide formation proceeded smoothly between acid chlorides and less nucleophilic and stereocongested amines such as 2,6-dichloroaniline. (iii) This protocol was applied to the successful synthesis of two agrochemicals, bromobutide and carpropamid.
