反应详情

To the mixture of ethyl 5-amino-2-chlorobenzoate, cyclopropanecarboxaldehyde (458 μl) and acetic acid (1.43 ml) dissolved in methanol (20 ml), α-picoline borane (804 mg) was added at ice cool temperature, and was stirred under nitrogen atmosphere overnight at room temperature. After the reaction mixture was concentrated under reduced pressure, sodium hydrogencarbonate aqueous solution was added to the residue, and the mixture was extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by silica gel chromatography, and ethyl 2-chloro-5-(cyclopropylmethylamino)benzoate (881 mg) and ethyl 5-[bis(cyclopropylmethyl)amino]-2-chlorobenzoate (423 mg) were obtained.

1. temperaturecool temperature
2. concentrationAfter the reaction mixture was concentrated under reduced pressure, sodium hydrogencarbonate aqueous solution
3. additionwas added to the residue
4. extractionthe mixture was extracted with ethyl acetate
5. washThe organic layer was washed with brine
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by silica gel chromatography, and ethyl 2-chloro-5-(cyclopropylmethylamino)benzoate (881 mg)