4-Bromophenylhydrazine hydrochloride → 5-Amino-1-(4-bromophenyl)-3-(4-tolyl)pyrazole-4-carboxamide

Participants

Reaction Steps

The title compound was prepared from 2-cyano-3-methylthio-3-(4-tolyl)acrylamide (928 mg, 4.0 mmol), 4-bromophenylhydrazine hydrochloride (894 mg, 4.0 mmol) and sodium hydroxide (176 mg, 4.4 mmol) following the procedure used for the compound of Example 12. The crude product was subjected to column chromatography (SiO2, 10% methanol in CH2Cl2) and recrystallisation from ethyl acetate to give the title compound as white crystals (470 mg) m.p. 222-223°. δH (CDCl3) 7.63 (2H, dt, J 8.8, 2.2 Hz), 7.52 (2H, dt, J 8.5, 2.6 Hz), 7.48 (2H, d, J 7.4 Hz), 7.28 (2H, d, J 8.3 Hz), 5.74 (2H, br s), 5.29 (2H, br s), 2.41 (3H, s).

Provenance & Evidence