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
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