Trimethyl borate → B-[2-[[(4,5-dimethyl-3-isoxazolyl)[(2-methoxyethoxy)methyl]amino]sulfonyl]phenyl]Boronic acid

Temperatur

-95 °C

To a solution of the title compound of step C (22.16 g, 52.85 mmol) in 264 ml THF at -95° C., n-butyl lithium (2M solution in pentane, 29.07 ml, 58.14 mmol) was added. The mixture was stirred at -95° C. for 10 minutes and trimethylborate (6.59 g, 63.42 mmol) was added and stirred at -78° C. for 15 minutes. The cold bath was removed and the mixture was warmed to room temperature slowly and stirred at room temperature for 0.5 hr. The mixture was then cooled to 0° C. and 100 ml 3N HCl was added dropwise. After stirring for 30 minutes, the mixture was extracted with CH2Cl2 (300 ml, 100 ml). The combined organic extracts were washed with 30 ml brine, dried and concentrated to give 2-borono-N-(4,5-dimethyl-3-isoxazolyl)-N-[(2-methoxyethoxy)methyl]benzenesulfonamide as a gum.

1. stirringstirred at -78° C. for 15 minutes
2. customThe cold bath was removed
3. temperaturethe mixture was warmed to room temperature slowly
4. stirringstirred at room temperature for 0.5 hr
5. temperatureThe mixture was then cooled to 0° C.
6. addition100 ml 3N HCl was added dropwise
7. stirringAfter stirring for 30 minutes
8. extractionthe mixture was extracted with CH2Cl2 (300 ml, 100 ml)
9. washThe combined organic extracts were washed with 30 ml brine
10. customdried
11. concentrationconcentrated

ORD-Eintrag

ord-c8d06ed203f949168666c3dd01881642

Quelldatensatz

uspto-grants-1998_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05846990