title: New convenient four-component synthesis of 6-amino-2,4-dihydropyrano[2,3-c]pyrazol-5-carbonitriles and one-pot synthesis of 6'-aminospiro[(3H)-indol-3,4'-pyrano[2,3-c]pyrazol]-(1H)-2-on-5'-carbonitriles.
abstract: This report describes a new four-component synthesis of substituted and spiro-conjugated 6-amino-2H,4H-pyrano[2,3-c]pyrazol-5-carbonitriles directly from aromatic aldehydes or heterocyclic ketones, malononitrile, beta-ketoesters, and hydrazine hydrate. The method provides a convenient one-pot route toward divers 2,4-dihydropyrano[2,3-c]pyrazoles, whereas a modified one-step sequential protocol gives access to spiro[indoline-3,4'-pyrano[2,3-c]pyrazol]-2-ones.
authors.affiliation: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation.
authors.forename: Yuri M
authors.initials: YM
authors.lastname: Litvinov
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Shestopalov
authors.forename: Lyudmila A
authors.initials: LA
authors.lastname: Rodinovskaya
authors.forename: Anatoliy M
authors.initials: AM
authors.lastname: Shestopalov
mesh_terms: D006571:Heterocyclic Compounds / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009570:Nitriles / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D006571:Heterocyclic Compounds; D009570:Nitriles