Hydrochloric Acid → 3,4-Dihydro-2H-1,4-benzoxazin-6-amine

Temperature

80 °C

6-Amino-2H-benzo[b][1,4]oxazin-3(4H)-one (590 mg, 3.6 mmol) was added to a THF solution of borane tetrahydrofuran complex (9 mL, 1M solution) and the reaction mixture was refluxed for 2.5 h. EtOH (2 mL) was added and stirred at 70° C. for 1 h before 1 mL HCl (conc.) was added. The mixture was stirred at 80° C. overnight then the volatiles were removed under vacuum to leave a crude reside. The residue was dissolved in water, NaOH was added until pH˜10, and the mixture was extracted with CH2Cl2. The organic phase was washed with water and the solvent was removed under vacuum. The residue was purified by column chromatography on silica gel to give the product (274 mg, 51%) as a colorless oil.

1. temperaturethe reaction mixture was refluxed for 2.5 h
2. additionwas added
3. customthe volatiles were removed under vacuum
4. customto leave a crude reside
5. extractionthe mixture was extracted with CH2Cl2
6. washThe organic phase was washed with water
7. customthe solvent was removed under vacuum
8. customThe residue was purified by column chromatography on silica gel

ORD record

ord-c67f3e46d0fb4a3fb1d7089e312c0f84

Source dataset

uspto-grants-2009_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07576099B2