Orthoamide und Iminiumsalze, LXXVI [1]. Ein weiterer Beitrag zur Chemie der Trialkoxyacetonitrile/ Orthoamides and Iminium Salts LXXVI [1]. A Further Contribution to the Chemistry of Trialkoxyacetonitriles
trialkoxyacetonitriles 3 to give α- imino-orthocarboxylic acid trialkylesters 12, 14 and 20, which form an equilibrium with the tautomeric enamines 13, 15 and 21. The enamines 21 react with N,N-dimethylformamide dimethylacetal (24) to give amidines 25 which are cyclized to pyridinium salts 28 and 29 on treatment with benzyl bromide and acetyl chloride, respectively. The reaction of the enaminonitrile 13a