Lawesson's reagent → 1-tert-butyl-5-(4-fluorophenyl)-1H-pyrazole-4-carbothioamide
Reaction equation
[C:1]([N:5]1[C:9]([C:10]2[CH:15]=[CH:14][C:13]([F:16])=[CH:12][CH:11]=2)=[C:8]([C:17]([NH2:19])=O)[CH:7]=[N:6]1)([CH3:4])([CH3:3])[CH3:2].COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:29])=CC=1>C1COCC1>[C:1]([N:5]1[C:9]([C:10]2[CH:15]=[CH:14][C:13]([F:16])=[CH:12][CH:11]=2)=[C:8]([C:17](=[S:29])[NH2:19])[CH:7]=[N:6]1)([CH3:4])([CH3:3])[CH3:2]Participants
4
Procedure
A solution of the compound (4.00 g, 15.31 mmol) obtained in step 3 and Lawesson's reagent (6.19 g, 15.31 mmol) in THF (50 mL) was stirred at 50° C. for 1.5 hr. The reaction mixture was concentrated under reduced pressure, and the residue was purified by NH-silica gel column chromatography (solvent gradient; 2→65% ethyl acetate/hexane) to give 1-tert-butyl-5-(4-fluorophenyl)-1H-pyrazole-4-carbothioamide (2.75 g, 9.91 mmol, 65%) as a pale-yellow powder.