1,1'-Carbonyldiimidazole → 4-Methyl-3H-benzooxazol-2-one

Temperatur

0 °C

25.0 g (200 mmol) 2-amino-m-cresol and 70.4 mL (400 mmol) DIPEA were placed in 1.0 L DCM and cooled to 0° C. To this a solution of 38.0 g (227 mmol) CDI was added dropwise over 30 min. The mixture was stirred for 30 min at 0° C., then stirred overnight at RT. After evaporation of the reaction mixture i. vac. down to half the volume, the aqueous phase was washed with water (2×250 mL), 1M aqueous potassium hydrogen sulphate solution (1×250 mL) and again water (1×250 mL). The organic phase was evaporated down i. vac. The crude product left as a solid was triturated with a mixture of diethyl ether and PE, the precipitated solid was suction filtered, washed with PE and dried i. vac.

1. stirringstirred overnight at RT
2. customAfter evaporation of the reaction mixture i
3. washdown to half the volume, the aqueous phase was washed with water (2×250 mL), 1M aqueous potassium hydrogen sulphate solution (1×250 mL) and again water (1×250 mL)
4. customThe organic phase was evaporated down i
5. waitThe crude product left as a solid
6. customwas triturated with a mixture of diethyl ether and PE
7. filtrationfiltered
8. washwashed with PE
9. customdried i

ORD-Eintrag

ord-5974944588dd404589cdfbbbbdd14c62

Quelldatensatz

uspto-grants-2014_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08629137B2