Trifluoroacetic acid → HCID 178470493, compound
Reaction equation
C1C(=O)N([I:8])C(=O)C1.C(O)(C(F)(F)F)=O.[NH:16]1[C:20]([C:21]([O:23][CH2:24][CH3:25])=[O:22])=[CH:19][CH:18]=[N:17]1>CC#N>[I:8][C:19]1[C:20]([C:21]([O:23][CH2:24][CH3:25])=[O:22])=[N:16][NH:17][CH:18]=1Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
NIS (8.83 g, 39.2 mmol) and TFA (0.825 mL, 10.70 mmol) were added to a stirred solution of ethyl 1H-pyrazole-5-carboxylate (5 g, 35.7 mmol) in CH3CN (120 mL) under Ar. The reaction mixture was stirred for 6 hr at rt, concentrated, diluted with a saturated aqueous solution of NaHCO3, and extracted with EtOAc. The combined organic layers were washed with a saturated aq. NaHCO3 solution, dried over Na2SO4 and evaporated. The crude material was purified by silica gel column chromatography (hexane/EtOAc 10-50%) to afford the title product (8.31 g, 31.2 mmol, 88% yield) as a white solid. tR: 3.47 min (HPLC 1); tR: 0.72 min (LC-MS 2); ESI-MS: 267 [M+H]+ (LC-MS 2); Rf=0.55 (hexane/EtOAc 1:1).