Pyridinethiones. IX preparation of ricinidine, thioricinidine and other 2(1H)-pyridones and -thiones related to nicotinic acid
Abstract
2(1H)-Pyridones and -thiones related to 1-substituted nicotinic acid derivatives have been prepared via the corresponding l-substituted-3-formyl-2(1H)-pyridones and -thiones. A number of synthetic procedures for the interconversion of functional groups in these nicotinic acid derivatives are given i.e. preparation of the aldoximes, nitriles, carboxamides and carboxylic acids as well as the 3- hydroxyalkyl derivatives. The course of the basic peroxide oxidation of the l-substituted-3-formyl-2(1H)-pyridinethiones is found to be very dependent upon the electronegativity of the 1-substituent. A preparation of ricinidine is also described.