79000-08-1Relevant academic research and scientific papers
An improved preparation of 3-alkoxypyrazoles
Guillou, Sandrine,Bonhomme, Frederic J.,Janin, Yves L.
experimental part, p. 3504 - 3508 (2009/05/09)
The condensation between alkyl acetoacetates and hydrazines constitutes the very well-known Knorr synthetic method leading to pyrazol-3/5-ones. However, contemporary reports describe an alternate reaction pathway leading to low yields of 3/5-alkoxypyrazoles using hydrazine salts. No general method for the selective synthesis of 3-alkoxypyrazoles has been reported to date, hence we focused on this side reaction in an attempt to turn it into the main transformation. Depending on the starting material, various 3-alkoxypyrazoles (methoxy, ethoxy, benzyloxy, isopropoxy, allyloxy) were obtained in up to 56% yield. Georg Thieme Verlag Stuttgart.
PHOTOCHEMICAL BENZYL MIGRATION IN 3-PYRAZOLIN-5-ONES
Singh, Gurbakhsh,Singh, Devender,Ram, Ram Nath
, p. 2213 - 2216 (2007/10/02)
The 3-pyrazolin-5-ones (1) undergo light induced rearrangement by N -> O and N -> C4 benzyl migrations.A free radical mechanism is proposed.
