Answers are grounded in this paper and cite their sources.
Literature data on the title reactions are reviewed and further examples given particularly with dialkylhydrazines and hydrazones. Compounds derived from 2-ethoxycarbonyl-4,6-diphenylpyrylium tend to cyclise and new examples of the dihydropyrazoloquinoline (27) and oxidopyrido[1,2-b]pyridazinium [(62)–(64)] ring systems are described.
No takes yet. Share an insight, caveat, or question.
Katritzky et al. (1981) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: