4-Chloroaniline → HCID 14118806, compound

Reaction equation

[NH2:1][C:2]1[N:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[N:5]=[CH:4][C:3]=1[C:13]([OH:15])=O.[Cl:16][C:17]1[CH:23]=[CH:22][C:20]([NH2:21])=[CH:19][CH:18]=1>S(Cl)(Cl)=O.C(Cl)Cl>[Cl:16][C:17]1[CH:23]=[CH:22][C:20]([NH:21][C:13]([C:3]2[CH:4]=[N:5][N:6]([C:7]3[CH:8]=[CH:9][CH:10]=[CH:11][CH:12]=3)[C:2]=2[NH2:1])=[O:15])=[CH:19][CH:18]=1

Participants

Procedure

A suspension of 5-amino-1-phenyl-1H-pyrazole-4-carboxylic acid (500 mg, 2.46 mmol) in thionyl chloride (2.0 mL) is stirred at room temperature for about 15 min before it becomes a clear solution. After removal of the solvent, the crude acid chloride is taken in anhydrous DCM (5.0 mL), and transferred dropwise to a solution of 4-chloroaniline (376.7 mg, 2.95 mmol) and TEA (1.03 mL, 7.38 mmol) in anhydrous DCM (5.0 mL) at 0° C. The reaction mixture is allowed to warm up to room temperature in an hour and lots of precipitate is generated. After filtration, the precipitate is washed with water, followed by small amount of DCM, and air-dried to provide crude 5-amino-1-phenyl-1H-pyrazole-4-carboxylic acid (4-chloro-phenyl)-amide (506.2 mg, 66% yield) as a white solid product; HPLC-MS calculated for C16H13ClN4O (M+H+) 313.1. Found: 313.0.