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

Reaction equation

[C:1]([C:3](=[C:7](SC)[C:8]1[CH:13]=[CH:12][C:11]([CH3:14])=[CH:10][CH:9]=1)[C:4]([NH2:6])=[O:5])#[N:2].Cl.[Br:18][C:19]1[CH:24]=[CH:23][C:22]([NH:25][NH2:26])=[CH:21][CH:20]=1.[OH-].[Na+]>>[NH2:2][C:1]1[N:25]([C:22]2[CH:23]=[CH:24][C:19]([Br:18])=[CH:20][CH:21]=2)[N:26]=[C:7]([C:8]2[CH:13]=[CH:12][C:11]([CH3:14])=[CH:10][CH:9]=2)[C:3]=1[C:4]([NH2:6])=[O:5]

Participants

Reactant 3

HCID 121574-Bromophenylhydrazine hydrochloride

HCID 14798Sodium Hydroxide

HCID 542422372-Cyano-3-methylthio-3-(4-tolyl)acrylamide2×

Product 1

HCID 538502285-Amino-1-(4-bromophenyl)-3-(4-tolyl)pyrazole-4-carboxamideYield 31.7%

Procedure

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).