74669-41-3Relevant articles and documents
Acylation of 4-Pyridone
Effenberger, Franz,Mueck, Alfred Otto,Bessey, Eberhard
, p. 2086 - 2099 (2007/10/02)
Only N-acyl-4-pyridones (5) are isolable from the acylation of 4-pyridone (1) with aliphatic carboxylic anhydrides, and chlorides or free acids in the presence of dicyclohexylcarbodiimide.Similarly the reaction of 1with ortho substituted derivatives of benzoic acid leads only to N-acylation products 8, while benzoyl chloride as well as benzoic acid derivatives 7i-s (meta or para substituted), 3,5-dinitrobenzoyl chloride, and the 2,4-dimethyl substituted benzoyl chlorides 7v-z give exclusively 4-(acyloxy)pyridines 9.Reaction of phthaloyl chloride (10) with 1 yields both N- and O-acylation products.In solution even at room temperature the N-acylation compounds 2 and 8 are in equilibrium with the (acyloxy)pyridines 3 and 9, respectively.The position of the equilibrium depends mainly on the structure of the acyl residue, it is, however, also effected by temperature and polarity of the solvent.