Formic Acid → 4-Boc-3-(2-carboxy-ethyl)-morpholine

Temperatur

100 °C

A mixture of formic acid (2.26 mL, 58.9 mmol) and triethylamine (3.36 mL, 24.11 mmol) was stirred for 5 minutes in an ice bath. To the mixture were added tert-butyl 3-formylmorpholine-4-carboxylate (0.47 g, 2.2 mmol) and Meldrum's acid (0.32 g, 2.2 mmol) in turn at 0° C. The reaction mixture was heated at 100° C. for 5 hours, and cooled down in an ice bath. To the resulting mixture was added aqueous NaOH solution (2 mol/L, 40 mL). The aqueous layer was extracted with EtOAc (50 mL×3) and the organic layer was discarded. To the aqueous layer was added EtOAc (80 mL), and the mixture was adjusted to pH 4-5 with HCl (1 mol/L) under stirring. The aqueous layer was extracted with EtOAc (80 mL). The organic layer was dried over anhydrous Na2SO4, then filtered and the filtrate was concentrated in vacuo to give the title compound as a white solid (0.23 g, 40%). The compound was characterized by the following spectroscopic data:

1. temperaturecooled down in an ice bath
2. extractionThe aqueous layer was extracted with EtOAc (50 mL×3)
3. additionTo the aqueous layer was added EtOAc (80 mL)
4. stirringunder stirring
5. extractionThe aqueous layer was extracted with EtOAc (80 mL)
6. dry with materialThe organic layer was dried over anhydrous Na2SO4
7. filtrationfiltered
8. concentrationthe filtrate was concentrated in vacuo

ORD-Eintrag

ord-5a06b252f6b54bf4ada29a6f44e92503

Quelldatensatz

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09340538B2