Cross-condensation of derivatives of cyanoacetic acid and carbonyl compounds. 2. One-pot synthesis of substituted 2-amino-7-methyl-5-oxo-4,5-dihydropyrano[4,3-b]pyrans in ethanol and ionic liquid [bmim][PF6]A. M. Shestopalov; S. G. Zlotin; A. A. Shestopalov; V. Yu. Mortikov; L. A. Rodinovskaya · 2004