p-Toluenesulfonic acid → HCID 78165247, compound

Reaction equation

C1(C)C=CC(S(O)(=O)=O)=CC=1.[C:12]([C:20]1[CH:25]=[CH:24][C:23]([C:26](=O)[C:27]2[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=2)=[CH:22][CH:21]=1)(=[O:19])[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.[NH2:34][NH:35][C:36]([NH2:38])=[S:37]>CO>[C:12]([C:20]1[CH:25]=[CH:24][C:23]([C:26](=[N:34][NH:35][C:36]([NH2:38])=[S:37])[C:27]2[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=2)=[CH:22][CH:21]=1)(=[O:19])[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Participants

Procedure

A catalytic amount of p-toluenesulfonic acid was added to a solution of 1,4 dibenzoylbenzene 1 (0.286 g, 1 mmol) in anhydrous methanol (10 mL). After stirring at reflux for 10 min, thiosemicarbazide (0.182 g, 2 mmol) was added to the reaction mixture and stirred for 12 h under an inert atmosphere of nitrogen gas. After 12 h, methanol was removed under reduced pressure and 10 mL of water was then added. The products were extracted with ethyl acetate (2×20 mL) and the combined organic phases were washed with brine, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure. Purification using flash chromatography (silica gel, hexanes:ethyl acetate, gradient 70:30) afforded 4-benzoyl benzophenone thiosemicarbazone 4 (0.012 g, 0.033 mmol) in a 3.3% yield. HRMS (ESI) calculated for C21H17N3OSH+ (M+H)+ 360.11651, found 360.11649.