Sodium Hydroxide → 4-(1,4-dimethyl-1H-pyrazol-5-yl)-5-methyl-2-thiophenecarboxylic acid
Reaction equation
[CH3:1][N:2]1[C:6]([C:7]2[CH:8]=[C:9]([C:13]([O:15]C)=[O:14])[S:10][C:11]=2[CH3:12])=[C:5]([CH3:17])[CH:4]=[N:3]1.[OH-].[Na+]>O1CCCC1>[CH3:1][N:2]1[C:6]([C:7]2[CH:8]=[C:9]([C:13]([OH:15])=[O:14])[S:10][C:11]=2[CH3:12])=[C:5]([CH3:17])[CH:4]=[N:3]1Participants
4
Procedure
A solution of methyl 4-(1,4-dimethyl-1H-pyrazol-5-yl)-5-methyl-2-thiophenecarboxylate (240 mg, 0.96 mmol) in 6N sodium hydroxide (3.20 ml, 19.18 mmol) and tetrahydrofuran (4.79 ml) was stirred at 70° C. in a sealed tube for 1 h. The resulting solution was cooled and then partitioned between H2O-DCM. The aqueous phase was adjusted to pH ˜4 and then washed several times with DCM. The combined organic fractions were dried over Na2SO4 and concentrated affording 4-(1,4-dimethyl-1H-pyrazol-5-yl)-5-methyl-2-thiophenecarboxylic acid (217 mg, 0.92 mmol, 96% yield) as a yellow oil: LCMS (ES) m/e 236 (M+H)+.