2-(Ethoxymethylene)propanedinitrile → 5-amino-1-(2-fluoro-4-methanesulfonyl-phenyl)-1H-pyrazole-4-carbonitrile

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Reaction Steps

(2-Fluoro-4-methanesulfonyl-phenyl)-hydrazine (1 g, 4.89 mmol) and sodium methoxide (30 mg, 0.489 mmol) were dissolved in methanol under N2 at room temperature. The mixture was stirred for 10 min and 2-ethoxymethylene-malononitrile (0.6 g, 4.91 mmol) was added. The reaction mixture was stirred for 30 min and then brought to reflux for 2 hours. The solvent was removed under reduced pressure; the residue was suspended in water and extracted with ethyl acetate. The organic layer was washed with water, brine and was dried over sodium sulfate. The solvent was concentrated, affording 5-amino-1-(2-fluoro-4-methanesulfonyl-phenyl)-1H-pyrazole-4-carbonitrile as a yellow solid (1.2 g, 87.5%). 1H NMR (400 MHz DMSO-d6) δ (ppm): 7.96 (d, 1H); 7.93 (m, 1H); 7.80 (s, 1H); 7.74 (m, 1H); 6.89 (s, 2H); 3.24(s, 3H). Exact mass calculated for C11H9FN4O2S 280.04, found 281.30 (MH+, 100%).

Provenance & Evidence