反应详情

286 g (2.0 mols+10% excess) of maleic acid-monomethyl ester are placed into a glass flask fitted with a blade stirrer, thermometer, reflux condenser and dropping funnel, and, with ice-water cooling, 400 ml of triethylamine are added dropwise at 6°-11° C. internal temperature within 1 hour and 35 minutes. The cooling is subsequently removed, 204 g (2.0 mols) of 3-dimethylaminopropylamine are quickly added, and the mixture is reacted for 10 minutes at 87°-90° C. and is then cooled to room temperature; the crystalline crude product is mixed with 1 liter of acetone, the suspension is filtered, and the filter residue is washed with acetone. The yield after drying at 80° C. in vacuo is 296 g (63.7% of theory) of a crystalline aspartic acid derivative, which melts at 171°-172° C.

1. customfitted with a blade stirrer
2. temperaturethermometer, reflux condenser
3. custom35 minutes
4. customThe cooling is subsequently removed
5. customthe mixture is reacted for 10 minutes at 87°-90° C.
6. filtrationthe suspension is filtered
7. washthe filter residue is washed with acetone
8. customThe yield
9. customafter drying at 80° C. in vacuo