“…As a result, the 5,6,7,8‐tetrafluoro‐1 H ‐pyrazolo[3,4‐ b ]quinolines were synthesized, applying the reaction used earlier for the preparation of substituted acridines . The results of the Abramov et al study on the reaction of pentafluorobenzaldehyde with 1 H ‐pyrazol‐5‐amines seem to be different from those found earlier by Joshi et al , who obtained bis ‐pyrazolo[3,4‐ b ,4′,3′‐ e ]pyridines ( BPP ), rather than PQ, in a similar reaction performed in non‐solvent conditions at 220–240°C. They only proved the structures of the products by using elemental analysis of nitrogen (with no apparatus details), neither 1 H‐NMR nor 13 C‐NMR spectra were present, and the melting point of the suggested product, 1,3,5,7‐tetraphenyl‐4‐(pentafluorophenyl)‐ bis ‐pyrazolo[3,4‐ b ,4′,3′‐ e ]pyridine, is similar to that found for the 5,6,7,8‐tetrafluoro‐1 H ‐pyrazolo[3,4‐ b ]quinoline by Abramov.…”