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From Renewable Levulinic Acid to a Diversity of 3‐(Azol‐3‐yl)Propanoates
Author(s) -
Flores Alex F. C.,
Piovesan Luciana A.,
Pizzuti Lucas,
Flores Darlene C.,
Malavolta Juliana L.,
Martins Marcos A. P.
Publication year - 2014
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.1774
Subject(s) - chemistry , levulinic acid , isoxazole , hydrogen bond , pyrazole , molecule , medicinal chemistry , stereochemistry , crystal structure , organic chemistry , catalysis
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‐(1 H ‐pyrazol‐3‐yl)propanoates, and the respective acid derivatives, in good (70–95%) yields. The crystal structure for ethyl 5‐(3‐ethoxy‐3‐oxopropyl)‐1 H ‐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.