6-Amino-2,4-dihydropyrano pyrazoles

Litvinov YM, Shestopalov AA, Rodinovskaya LA, Shestopalov AM (2009) 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 -(lH)-2-on-5 -carbonitriles. J Comb Chem 11 914—919... 

Darandale, S. N., Sangshetti, J. N. and Shinde, D. B. 2012. Ultrasound mediated, sodium bisulfite catalyzed, solvent free synthesis of 6-amino-3-methyl-4-substitued-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile. J. Korean Chem. Soc. 56 328-333. 

Amino-4-(benzo[(f [l,3]dioxol-4-yl)-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile (5c) Solid, mp 204-206 °C reaction time 65 min yield 85%... 

Ethyl 6-amino-5-cyano-3-methyl-2,4-dihydropyrano [2,3-c]pyrazole-4-carboxylate (5f) Solid, mp 187-189 °C reaction time 25 min 5deld 90%... 

Amino-4-(4-chlorophenyl)-3 -methyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile (4gb). White solid, mp 233-235 °C yield 84%... 

A. Siddekha, A. Nizam, M.A. Pasha, An efficient and simple approach for the synthesis of pyranopyrazoles using imidazole (catalytic) in aqueous medium, and the vibrational spectroscopic studies on 6-amino-4-(4 -meihoxyphenyl)-5-cyano-3-methyl-l-phenyl-l,4-dihydropyrano[2,3-c]pyrazole using density functional theory, Spectrochim Acta A Mol. BiomoL Spectrosc. 81 (2011) 431-440. 

H. Mecadon, M.R. Rohman, M. Ra(bangshi, B. Myrboh, Y-Alumina as a recyclable catalyst for the four-component synthesis of 6-amino-4-alkyl/ aryl-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles in aqueous medium. Tetrahedron Lett 52 (2011) 2523-2525. 

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