反应详情

21 ml (42 mmol) of 2N sodium hydroxide solution are added at room temperature while stirring to a solution of 2.99 g (10 mmol) of N-[2-(chroman-3-yl)ethyl]-N-(2-methoxycarbonylethyl)-amine hydrochloride in 60 ml of methanol. After 5 minutes, 40 ml of water are added to the reaction mixture which is then stirred for 30 minutes at 50°-60°. After cooling, the mixture is concentrated by evaporation in vacuo. The residue is dissolved in 30 ml of water, and then 10 ml of hydrochloric acid (36% strength) are added and the whole is cooled in an ice bath. The crystals formed are filtered off with suction. 2.5 g (87.5%) of N-[2-(chroman-3-yl)ethyl]-N-(2-carboxyethyl)-amine hydrochloride are obtained (m.p. 186°-188°).

1. temperatureAfter cooling
2. concentrationthe mixture is concentrated by evaporation in vacuo
3. dissolutionThe residue is dissolved in 30 ml of water
4. addition10 ml of hydrochloric acid (36% strength) are added
5. temperaturethe whole is cooled in an ice bath
6. customThe crystals formed
7. filtrationare filtered off with suction