106932-30-3Relevant academic research and scientific papers
PYRIDINES. XIV - ACYLATION DE PYRIDYL-LITHIOENAMIDINES. SYNTHESE DE PYRIDYL-N-ACYLENAMIDINES ET DE PYRIDYLPYRIMIDONES-4.
Compagnon, Paul-Louis,Gasquez, Francoise,Kimny, Tan
, p. 57 - 64 (2007/10/02)
The mixture of PhLi:di- or tri-methylpyridine 1:PhCN:RCOCl (R = Me, Ph, EtO, Me2N) or PHCO2Me (molar ratio 3:1:3:3) leads through the intermediates primary lithioenamines 3 and lithioenamidines 4, to acylated products, N-acylenamines (enamides) 5, β-diketones and β-ketoesters 6, C-acylenamides 7, N-acyleneamidines 8 and their cyclization derivatives, pyridylhydroxypyrimidines 10 (yield up to 60 percent) and pyridyldihydropyrimidones 11 (yield up to 10 percent).Distillation of the crude extract leads to naphthyridones 12 (yield up to 10 percent) which result from thermocyclization of the enamides 5f, 5g and 7f.Various by-products are isolated such as N,N-dimethyl-N',N'-diphenylmethyleneurea resulting from N-lithiodiphenylketimine and phenacylpyridines 13.Crotonization and oxidation of the latter compounds lead to the aza-analogues 14, 15 of dibenzoylstilbenes.
