Polyfunctional Pyrazoles. 8*. Synthesis of 6-Alkyl-2-Aryl-2H-Pyrazolo[4,3-d]Pyrimidine-5,7(4H,6H)-Diones based on Ethyl 1-Aryl-4-Isocyanatopyrazole-3-Carboxylates

Polyfunctional Pyrazoles. 10*. Synthesis of 5-OXO-4,5,7,9-Tetrahydropyrazolo[3,4-е][1,2,3]-Triazolo[1,5-а][1,3]Diazepine-3-Carboxamides in a Tandem Reaction of Ethyl 4-(Azido-Methyl)Pyrazole-3-Carboxylates with Cyanoacetamides

“…It should be noted that the absence of signals in the downfield region (160-190 ppm) of the 13 C NMR spectra excludes the possibility for the formation of the alternative Claisen condensation/cycloaddition tandem reaction products, 9-oxo-5,7,9,10-tetrahydropyrazolo[3,4-e]tetrazolo[1,5-a]azepine-10-carboxamides. Employing the APT method for the analysis of 13 C NMR spectra and comparison with published data [8,13] allowed for a comparatively accurate assignment of signals to the corresponding carbon atoms in the triazolodiazepine cycle: C-3 (127-128 ppm), C-3a (137-139), C-5 (157-159), C-5a (141-143), C-8a (116-118), C-9 (42-43 ppm).…”