2-Propenoic acid, 2-cyano-3-ethoxy-, ethyl ester → ethyl 5-amino-1-cyclohexyl-1H-pyrazole-4-carboxylate

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Reaction Conditions

Reaction Steps

To a round bottom flask is added cyclohexyl-hydrazine hydrochloride (4.5 g, 30 mmol), 2-cyano-3-ethoxy-acrylic acid ethyl ester (5.1 g, 30 mmol), sodium bicarbonate (2.6 g, 30.9 mmol) and 40 mL of ethanol. The mixture is heated to 80° C. for 1 hour, cooled down to room temperature and concentrated. The residue is dissolved in chloroform and washed with water, dried over sodium sulfate. After removal of the solvent, the solid is recrystallized from ethyl acetate: 1HNMR (CDCl3): δ 7.40 (1 H, s), 4.77 (2 H, brs), 4.05 (2 H, q, J= 7.2 Hz), 3.50 (1 H, m), 1.61-1.71 (6 H, m), 1.50 (1 H, m), 1.02-1.21 (3 H, m), 1.11 (3 H, t, J= 7.2 Hz).

Provenance & Evidence