Sodium Bicarbonate → ethyl 1-[(4-carbamoyl-1,3-thiazol-2-yl)methyl]-1H-pyrazole-4-carboxylate

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Reaction Steps

To a solution (7 mL) of the compound (1.0 g, 3.56 mmol) obtained in Example 33a in N,N-dimethylformamide were added 1-ethyl-3-(3-dimethylaminopropyl)carboditmide hydrochloride (WSC, 820 mg, 4.27 mmol) and 1-hydroxy-1H-benzotriazole ammonium salt (704 mg, 4.63 mmol), and the mixture was stirred at room temperature for 4 hr. After confirmation of the termination of the reaction by TLC, saturated aqueous sodium hydrogen carbonate solution was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The obtained organic layer was washed with water and saturated brine, and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure. The obtained crude product was purified by column chromatography (hexane-ethyl acetate) and recrystallization (ethyl acetate-hexane) to give the title compound (524 mg, 52%) as colorless crystals.

Provenance & Evidence