A convenient synthesis of 3- and 5-amino-1H-pyrazoles via 3(5)-amino-4-(ethylsulfinyl)-1H-pyrazole desulfinylation - Université de Rennes Accéder directement au contenu
Article Dans Une Revue Heterocyclic communications Année : 2011

A convenient synthesis of 3- and 5-amino-1H-pyrazoles via 3(5)-amino-4-(ethylsulfinyl)-1H-pyrazole desulfinylation

Résumé

Syntheses of 5-amino-3-aryl- and 3-amino-5-aryl-1H-pyrazoles from β-bromo-α-(ethylsulfanyl)cinnamonitrile are described. The β-bromo-α-(ethylsulfanyl)cinnamonitriles were oxidized with H2O2 to the corresponding β-bromo-α-(ethylsulfinyl)cinnamonitriles. Subsequent treatment of the resulting sulfoxides with hydrazine hydrate or methylhydrazine followed by hydrochloric acid hydrolysis afforded 5-amino-3-aryl- and 3-amino-5-aryl-1H-pyrazoles, respectively, in good yields.

Dates et versions

hal-00736464 , version 1 (28-09-2012)

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Citer

Frédéric Lassagne, Katia Snégaroff, Thierry Roisnel, Ekhlass Nassar, Florence Mongin. A convenient synthesis of 3- and 5-amino-1H-pyrazoles via 3(5)-amino-4-(ethylsulfinyl)-1H-pyrazole desulfinylation. Heterocyclic communications, 2011, 17, pp.139-145. ⟨10.1515/hc.2011.026⟩. ⟨hal-00736464⟩
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