1-Hydroxybenzotriazole → ethyl 2-[({[4-({cyclohexyl[1-(3-ethoxyphenyl)-3-ethyl-1H-pyrazol-4-yl]methyl}amino)phenyl]carbonyl}amino)methyl]-2-ethylbutanoate

Participants

Reaction Steps

4-({Cyclohexyl[1-(3-ethoxyphenyl)-3-ethyl-1H-pyrazol-4-yl]methyl}amino)benzoic acid (0.18 g) synthesized in Example 92(2) was dissolved in N,N-dimethylformamide (3 mL), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.11 g), 1-hydroxybenzotriazole.monohydrate (0.09 g), ethyl 2-(aminomethyl)-2-ethylbutanoate hydrochloride (0.12 g) and triethylamine (0.09 mL) were added at room temperature, and the mixture was stirred overnight. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The extract was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (ethyl acetate:hexane=1:2, volume ratio) to give ethyl 2-[({[4-({cyclohexyl[1-(3-ethoxyphenyl)-3-ethyl-1H-pyrazol-4-yl]methyl}amino)phenyl]carbonyl}amino)methyl]-2-ethylbutanoate (0.18 g) as a yellow oil. This was dissolved in ethanol (2.0 mL), 1N aqueous sodium hydroxide solution (2.0 mL) was added at room temperature, and the mixture was stirred at 60° C. overnight. Ethanol was evaporated under reduced pressure, and 1N hydrochloric acid (2.0 mL) was added to the residue. The precipitate was washed with water to give the title object compound (0.17 g, 74%) as a colorless solid.

Provenance & Evidence