1639427-95-4Relevant articles and documents
From renewable levulinic acid to a diversity of 3-(Azol-3-yl)propanoates
Flores, Alex F. C.,Piovesan, Luciana A.,Pizzuti, Lucas,Flores, Darlene C.,Malavolta, Juliana L.,Martins, Marcos A. P.
, p. 733 - 740 (2014)
Efficient heterocyclization of methyl 7,7,7-trifluoro-4-methoxy-6-oxo-4- heptenoate and methyl 7,7,7-trichloro-4-methoxy-6-oxo-4-heptenoate into isoxazole and pyrazole derivatives that represent a new type of glutamate-like 3-(trihalomethylated-1,2-azol-3-yl)propanoate is reported. Preparation of the key methyl 7,7,7-trihalo-4-methoxy-6-oxohept-4-enoate precursors from levulinic acid is also described. The synthetic potential of this synthetic protocol was indicated by the production of several methyl and ethyl 3-(isoxazol-3-yl) propanoates and 3-(1H-pyrazol-3-yl)propanoates, and the respective acid derivatives, in good (70-95%) yields. The crystal structure for ethyl 5-(3-ethoxy-3-oxopropyl)-1H-pyrazole-3-carboxylate (10c) has been determined by monocrystal X-ray diffraction analysis. The N-H...H intermolecular hydrogen bonds join the molecules into catamer.