Carbamate → [1-(4-Benzyloxycarbonylamino-benzyl)-3,5-dimethyl-1H-pyrazol-4-yl]-acetic acid

Participants

Reaction Steps

Carbamate formation: To a solution of [1-(4-amino-benzyl)-3,5-dimethyl-1H-pyrazol-4-yl]-acetic acid methyl ester (intermediate 1.1.3, 70 mg, 0.26 mmol) in dichloromethane (1 mL) was added diisopropylethylamine (55 μL, 0.32 mmol) and benzyl chloroformate (55 μL, 0.39 mmol). The reaction mixture was stirred for 18 h at room temperature. The reaction mixture was filtered over Alox B, eluting with 10% methanol in dichloromethane. Saponification: After removing the volatiles under reduced pressure, the remaining residue was dissolved, in methanol (1 mL) and treated with aqueous NaOH solution (4 M, 0.2 mL). The mixture was neutralized with aqueous HCl and purified via preparative reversed phase HPLC (gradient of methanol in water+0.1% NH3).

Provenance & Evidence