Sodium Hydroxide → 4-(4-chloro-1-methyl-1H-pyrazol-5-yl)-5-(methyloxy)-2-thiophenecarboxylic Acid

Participants

Reaction Conditions

Reaction Steps

NCS (382 mg, 2.80 mmol) was added in portions to a 50 mL sealed tube reactor containing methyl 5-(methyloxy)-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (642 mg, 2.54 mmol) [prepared according to the procedure of Example 185] in Tetrahydrofuran (THF) (12 mL) at room temperature. The mixture was heated to 70° C. for 1 hour. The reaction was cooled to room temperature, 6N NaOH (10 mL, 60.0 mmol) was added and the mixture stirred an additional 3 h at 70° C. The mixture was partitioned between CHCl3 and H2O and the aqueous layer was made acidic with 6N HCl. The organic layer was dried over Na2SO4 and concentrated affording the title compound (759 mg, 2.51 mmol, 98%) which was used without further purification: LC-MS (ES) m/z=273 (M+H)+.

Provenance & Evidence