Catalyst-free Synthesis of Mono and Bis Spiro Pyrazolopyridines in DSDABCO as a Novel Media

Abstract

In this work, multicomponent synthesis of mono and bis spiro-pyrazolopyridines from isatin derivatives, indanedione and 3-methyl-5-aminopyrazole at the presence of 1,4-disulfo-1,4-diazoniabicyclo[2.2.2]octane chloride (DSDABCO) as a novel ionic liquid media is reported. The present methodology offers several advantages such as simple procedure, mild conditions, excellent yields, green media and reduced environmental consequences. The ionic liquid was recovered and reused. The structures of the synthesized spiro-pyrazolopyridine compounds were confirmed by 1H, ¹³C NMR and FTIR spectral data and elemental analyses.