GENERAL METHOD: (4-Fluorophenyl)hydrazine (0.001 mol) was mixed with 10 mL of ethanol, stirred and heated to reflux. Subsequently, ethoxymethylene malononitrile (0.001 mol) dissolved in 10 mL of ethanol was added slowly and dropwise. The reaction mixture was kept at reflux for 2 hours. After completion of the reaction, the mixture was poured into 50 mL of ice water. The precipitate was collected by filtration and washed with cold water to afford 5-amino-1-(4-fluorophenyl)-1H-pyrazole-4-carbonitrile (10a) in 61% yield. The product characterization data were as follows: melting point: 173-174 °C. IR (cm^-1): 3297-3183 (NH2); 2225 (CN); 1662; 1568. ^1H NMR (400 MHz, DMSO-d6, TMS, δ in ppm): 7.31-7.25 (m, 2H, H3', H5'); 7.54- 7.49 (m, 2H, H2', H6'); 7.67 (s, 1H, H3). ^13C NMR (100 MHz, DMSO-d6, TMS, δ in ppm): 73.2 (C4); 114.8 (CN); 116.3 (d, J = 22.8 Hz, C3', C5'); 126.9 (d, J = 8.9 Hz, C2', C6'); 133.7 (d, J = 2.8 Hz, C1'); 141.7 (C5); 151.4 (C3); 161.2 (d, J = 243.6 Hz, C4'). ^19F NMR (376 MHz, DMSO-d6, TMS, δ in ppm): -114.26. EI-MS [M + 1]^+: 203.07.
