Transformations of Alykl (5-Oxo-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)acetates into 5-Heteroaryl-3-oxo-2-phenyl-3,5-dihydro-2H-pyrazolo[4,3-c]pyridine-7-carboxylates
Abstract Alkyl (E)-2-(3-Alkyl-5-oxo-1-phenyl-1,5-dihydro-4H-pyrazol-4-ylidene)-5-(alkylamino)-1,3-dithiole-4-carboxylates have been obtained by condensation of 2-pyrazolin-5-ones with carbon disulfide followed by ring formation with phosphorylated hydroxyketenimines [generated in situ from Nef-isocyanide-Perkow reaction] in the presence of Et3N. The structure of target compounds was confirmed by X-ray
Methyl (5-oxopyrazol-3-yl)acetate N,S-ketene acetal as a new building block for the construction of pyrazolo[4,3-c]pyridines
作者:M. A. Prezent、S. V. Ruban、S. V. Baranin、Yu. N. Bubnov
DOI:10.1007/s11172-016-1403-2
日期:2016.4
Methyl (5-oxopyrazol-3-yl)acetate is added to methylthiocyanate C≡N bond in the presence of Ni(OAc)2 giving a corresponding heterocyclic N,S-ketene acetal. The latter compound was used as a convenient synthon in the synthesis of new pyrazolo[4,3-c]pyridin-3-ones and pyrazolo[4,3-c]pyridine-3,6-diones.
A facile one-pot, solvent-free synthesis of new pyrazolone-1,3-dithiolan hybrids through the reaction between 2-pyrazoline-5-ones, CS<sub>2</sub>, and <i>α</i>-chloroacetaldehyde