Methyl iodide → HCID 86721227, compound

Reaction equation

[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[C:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[CH:11][NH:10][N:9]=2)=[CH:4][CH:3]=1.[H-].[Na+].[CH3:20]I>C1COCC1>[F:1][C:2]1[CH:3]=[CH:4][C:5]([C:8]2[N:9]([CH3:20])[N:10]=[CH:11][C:12]=2[C:13]([O:15][CH2:16][CH3:17])=[O:14])=[CH:6][CH:7]=1

Participants

Procedure

To a solution of ethyl 3-(4-fluorophenyl)-1H-pyrazole-4-carboxylate (15.0 g, 64.0 mmol) in THF was added sodium hydride (55 wt % paraffin oil, 3.35 g, 77.0 mmol) at room temperature and methyl iodide (8.01 mL, 128 mmol) was successively added at room temperature. After stirring at room temperature for 15 min, the reaction mixture was poured into ice water. The mixture was extracted with ethyl acetate, the organic layer was washed with saturated brine and dried, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (solvent; 33% ethyl acetate/hexane) to give a mixture (1:1 (mol/mol), 14.2 g, 90%) of ethyl 5-(4-fluorophenyl)-1-methyl-1H-pyrazole-4-carboxylate and ethyl 3-(4-fluorophenyl)-1-methyl-1H-pyrazole-4-carboxylate as a brown oil.