| Popis: |
Publisher Summary This chapter presents the reactions of acetylenecarboxylic acids and their esters with nitrogen-containing heterocyclic compounds. Both acetylenedicarboxylic acid and its ester undergo Michael addition reactions with a variety of nucleophilic reagents. Acetylenedicarboxylic acid is known to combine with a number of pyrroles. Indole on standing with dimethyl acetylenedicarboxylate for 74 days give a 63% yield of the carbazole along with 74% of each of two 1:3 molar adducts and about 2% of a 2:1 molar adduct. Pyrazole and its 3,5-dimethyl and 3,4,5-trimethyl derivatives combined with two moles of dimethyl acetylenedicarboxylate giving products of similar ultraviolet absorption spectra to the parent pyrazoles. The chemical reaction of pyridine and alkylpyridines with dimethyl acetylenedicarboxylate in ether at low temperatures is discussed. Acridine and the ester in the presence of hot excess methanol, partially used as solvent, combine readily giving a high yield of the 1:1:1 molar trans adduct and the reaction is analogous to the well-known Michael addition reaction which usually gives trans products. |
