To study the scope and limitations of the use of complexed species of AlCl 3 in FriedelCrafts reactions, we investigated the acetylation and benzoylation of 2(3H)-benzoxazolone and 3-methyl-2(3H)-benzoxazolone varying the amide complexing agent. We replaced dimethylformamide by N-methylformamide, dimethylacetamide, pyrrolidone, N-methylpyrrolidone, tetramethylurea, and dimethylsulfoxide. However, there was no particular advantage of substituting dimethylformamide by another amide ligand. This can probably be ascribed to the fact that the complex formed between AlCl 3 and the complexing agent becomes too stable. Alternatively, a route using polyphosphoric acid and microwave activation was explored. The major advantage of running the reaction in a microwave oven was that a good yield was reached in a rather short period of time.
The 1,3‐dipolar cycloaddition (13DC) reactions of nitrile‐oxide NO 1 with two ethylenes, enamine 2a and enamine 2b, were computationally studied using B3LYP/6‐31G(d) DFT methods. The two possible ortho and meta regioselective channels were characterized and analyzed. The moderate polarity of these 13DC reactions is related to the high nucleophilic character of both ethylenes, and the moderate electrophilic nature of the NO 1, that accounts for the relatively low calculated activation energies. Analysis of different forms of energies along the different reaction channels indicates that the present 13DC reactions are completely ortho regioselective, accordingly to the experimental outcomes. Electron localization function analysis indicates that these 13DC reactions proceed via a nonconcerted (two‐stage) one‐step mechanism.
The synthesis of new 2(3H )-benzoxazolinonylcarboxamides starting from 2-amino-4,6-dimethylpyridine and 2(3H )-benzoxazolone which were designed as anti-inflammatory agents is described. These derivatives were synthesised from 2(3H )-(benzoxazolinon-6-yl)carboxylic acids, which were obtained by Friedel-Crafts acylation of 2(3H )-benzoxazolone derivatives with oxalyl chloride and acetylchloride in the presence of the AlCl 3 -DMF complex. The constitution of the products was supported by elemental analysis IR and 1 H NMR spectral data.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.