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.
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.
Litvinov
Yuri M
YM
N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation.
Shestopalov
Alexander A
AA
Rodinovskaya
Lyudmila A
LA
Shestopalov
Anatoliy M
AM
D006571:Heterocyclic Compounds / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009570:Nitriles / Q000138:chemical synthesis* / Q000737:chemistry
D006571:Heterocyclic Compounds; D009570:Nitriles