反应详情

To a solution of 3-methyl-N1-phenylbenzene-1,2-diamine (381 mg, 1.92 mmol) in anhydrous DCM (10 mL) were added (S)-2-tertbutoxycarbonylaminopropionic acid (399 mg, 2.11 mmol), HOBt (285 mg, 2.11 mmol), 4-methylmorpholine (464 μL, 4.22 mmol) and N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (405 mg, 2.11 mmol). The mixture was stirred at RT for 2 h then additional amounts of (S)-2-tertbutoxycarbonylaminopropionic acid (145 mg, 0.77 mmol) and of N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (148 mg, 0.77 mmol) were added. Stirring was continued for 18 h and then additional amounts of (S)-2-tertbutoxycarbonylaminopropionic acid (545 mg, 2.88 mmol), HOBt (285 mg, 2.11 mmol), 4-methylmorpholine (464 μL, 4.22 mmol) and of N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (553 mg, 2.88 mmol) were added. Stirring was continued for 24 h and then the crude mixture was purified by column chromatography (Si—PCC, gradient 0-40% EtOAc in cyclohexane) affording [(S)-1-(2-methyl-6-phenylaminophenylcarbamoyl)ethyl]carbamic acid tertbutyl ester as an orange oil (395 mg, 56%). LCMS: RT 3.69 min [M+H]+ 370.2.

1. stirringStirring
2. waitwas continued for 18 h
3. stirringStirring
4. waitwas continued for 24 h
5. customthe crude mixture was purified by column chromatography (Si—PCC, gradient 0-40% EtOAc in cyclohexane)