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Reaction of 1,2‐Diaza‐1,3‐butadienes with Aminophosphorus Nucleophiles: A Practical Access to New Phosphorylated Pyrazolones
Author(s) -
Attanasi Orazio A.,
Baccolini Graziano,
Boga Carla,
De Crescentini Lucia,
Giorgi Gianluca,
Mantellini Fabio,
Nicolini Simona
Publication year - 2008
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200800856
Subject(s) - chemistry , pyrazolones , nucleophile , hydrolysis , medicinal chemistry , cleavage (geology) , tris , reaction conditions , stereochemistry , catalysis , organic chemistry , biochemistry , geotechnical engineering , fracture (geology) , engineering
The reaction of 1,2‐diaza‐1,3‐butadienes with dibenzyl diisopropylphosphoramidite, methyl tetraisopropylphosphorodiamidite or tris(dimethylamino)phosphane under solvent‐free conditions gave stable α‐phosphoranylidene‐hydrazones that, in turn, were transformed into the corresponding 5‐oxo‐4‐phosphoranylidene‐4,5‐dihydro‐1 H ‐pyrazoles. X‐ray diffraction analysis of one of these derivatives is reported. α‐Phosphoranylidene‐hydrazones, derived from the reaction between 1,2‐diaza‐1,3‐butadienes with dibenzyl diisopropylphosphoramidite, were converted by hydrolytic cleavage into ( E )‐hydrazono‐phosphonates, which are useful for the preparation of the corresponding (3‐oxo‐2,3‐dihydro‐1 H ‐pyrazol‐4‐yl)phosphonamidates.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)