Aryl pyrazoles are compounds that display very interesting
biological activities. This chapter reviews
recent work of our group in the development of
synthetic strategies for the preparation of new
examples of these kinds of compounds to crop
protection.
A series of six N-aryl
pyrazoles was synthesized by Michael-type addition reaction. The molecules 5-
amino-1-aryl-1H-pyrazole-4-carbonitrile (3a-f) were
synthesized from (ethoxymethylene)malononitrile (1) and fluorinated and
non-fluorinated aryl hydrazines (2a-f) using ethanol and fluorinated
ethanol as solvents at reflux. An excellent
regio-selectivity was found when pyrazole de- rivatives
were formed as an exclusive product. No other
regioisomer or uncyclised hydrazide was observed.
Their structures were confirmed by spectroscopy data (1H, 13C, 19F, COSY
(correlation
spectroscopy), HSQC (heteronuclear single-quantum
correlation spectroscopy) and HMBC (heteronuclear multiple-bond correlation
spectroscopy); MS (mass-spectrometry). The yields ranged from good
to excellent (47% - 93%) under mild reaction
conditions. It would indicate a high selectivity in the
one-step work procedure. These products (3a-f) and
derivatives have a potential academic and
industrial use as key intermediates, in special for
application in crop protection.
Author
(s) Details
Laura Marcela Machuca
Instituto de Investigaciones Científicas (IDIC), Facultad de
Ingeniería y Tecnología, Universidad de la Cuenca del Plata (UCP). Corrientes
57, (3450) Goya, Corrientes, Argentina and Consejo Nacional de Investigaciones
Científicas y Técnicas (CONICET), Godoy Cruz 2290 (C1425FQB) Buenos Aires,
Argentina.
Marcelo César Murguía
Consejo Nacional de Investigaciones Científicas y Técnicas
(CONICET), Godoy Cruz 2290 (C1425FQB) Buenos Aires, Argentina and Laboratorio
de Química Aplicada (LAQUIMAP). Facultad de Bioquímica y Ciencias Biológicas,
Universidad Nacional del Litoral (UNL). CC 242 Ciudad Universitaria, Ruta
Nacional 168 (S3000ZAA) Santa Fe, Argentina
View Book :- https://bp.bookpi.org/index.php/bpi/catalog/book/235
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