Dimethylformamide → [2-(2,5-Dioxo-imidazolidin-1-yl)-ethyl]-carbamic acid tert-butyl ester

3-(2-Aminoethyl)-imidazolidine-2,4-dione hydrochloride (14.7 g., 82 mmol) was suspended in DCM (300 mL) and DIPEA (28 mL, 160 mmol) was added. The mixture was stirred for 15 min, and then BOC2O (19.7 g, 90 mmol) was added. The suspension was stirred for 1 h, and then DMF (45 mL) was added. The stirred suspension gradually became a clear solution over the next several h. Stirring was continued for a further 16 h, after which time a thick precipitate had formed. The mixture was concentrated to dryness in vacuo, ensuring the last traces of DMF were removed, and then dissolved in boiling EtOAc (200 mL). Hexane (800 mL) was added, the mixture cooled and allowed to stand for 1 h. The resulting product was collected by filtration. Yield=14.6 g, 73%.

1. stirringThe suspension was stirred for 1 h
2. stirringStirring
3. waitwas continued for a further 16 h
4. customafter which time a thick precipitate had formed
5. concentrationThe mixture was concentrated to dryness in vacuo
6. customwere removed
7. dissolutiondissolved
8. additionHexane (800 mL) was added
9. temperaturethe mixture cooled
10. waitto stand for 1 h
11. filtrationThe resulting product was collected by filtration

ORD-Eintrag

ord-ca543fa2b64445bdaef0acdd925e0801

Quelldatensatz

uspto-grants-2010_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07858785B2