Sulfuric Acid → 1-Benzyl-4-((4-fluorophenyl)amino)piperidine-4-carboxamide

Reaction equation

S(=O)(=O)(O)O.[CH2:6]([N:13]1[CH2:18][CH2:17][C:16]([NH:21][C:22]2[CH:27]=[CH:26][C:25]([F:28])=[CH:24][CH:23]=2)([C:19]#[N:20])[CH2:15][CH2:14]1)[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1.[OH-:29].[Na+]>O>[CH2:6]([N:13]1[CH2:14][CH2:15][C:16]([NH:21][C:22]2[CH:23]=[CH:24][C:25]([F:28])=[CH:26][CH:27]=2)([C:19]([NH2:20])=[O:29])[CH2:17][CH2:18]1)[C:7]1[CH:8]=[CH:9][CH:10]=[CH:11][CH:12]=1

Participants

Procedure

To 500 ml 90% sulfuric acid were slowly added at 0° C. 152 g (493 mmol) 1-benzyl-4-(4-fluoro-phenylamino)-piperidine-4-carbonitrile. The mixture was stirred at ambient temperature for 16 h, then cooled to 0° C., diluted with 200 ml water, pH was adjusted to 9 by addition of 5N NaOH and the aqueous mixture extracted with dichloromethane. The combined organic extracts were washed with brine, dried over Na2SO4, filtered and evaporated: 155 g 1-benzyl-4-(4-fluoro-phenylamino)-piperidine-4-carboxylic acid amide as light brown crystals: MS (ISP): 328.3 MH+.