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

Temperature

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. A solution of 38.0 g (227 mmol) 1.1′-carbonyldiimidazole was added dropwise thereto over 30 min. The mixture was stirred for 30 min at 0° C., then overnight at RT. After evaporation of the reaction mixture i.vac. down to half its 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 remaining 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. customovernight
2. customat RT
3. customAfter evaporation of the reaction mixture i.vac
4. washdown to half its 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)
5. customThe organic phase was evaporated down i.vac
6. customwas triturated with a mixture of diethyl ether and PE
7. filtrationfiltered
8. washwashed with PE
9. customdried i

ORD record

ord-4be035b5c2da40498f6ef08d00ba8060

Source dataset

uspto-grants-2013_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08450327B2