Chloroacetyl chloride → 7-benzenesulfonyl-4H-benzo[1,4]oxazin-3-one

A solution of 2-amino-5-benzenesulfonyl-phenol (0.392 g., 1.57 mmol) in 10 mL of acetonitrile was cooled to O° C. To this solution was added sodium bicarbonate (0.263 g., 3.14 mmol) in 4 mL water. With stirring, 2-chloroacetyl chloride (0.162 mL, 2.097 mmol) was added dropwise over 2 minutes. Stirring was continued for one hour as the reaction mix was warmed to room temperature. Potassium carbonate (0.261 g., 1.89 mmol) was then added and the system was warmed to reflux (85° C.) for two hours. The reaction mixture was added to 50 mL EtOAc, the aqueous fraction was separated and the organic layer was washed twice with 50 mL water, dried over Na2SO4 and concentrated in vacuo. The crude solid was recrystallized from a mixture of 30 mL each of ethanol and water to give 0.382 g (1.32 mmol, 84%) of 7-benzenesulfonyl-4H-benzo[1,4]oxazin-3-one as a yellow solid. MS: 288 (M−H)−. Step 6:

1. stirringStirring
2. additionmix
3. temperaturethe system was warmed
4. temperatureto reflux (85° C.) for two hours
5. customthe aqueous fraction was separated
6. washthe organic layer was washed twice with 50 mL water
7. dry with materialdried over Na2SO4
8. concentrationconcentrated in vacuo
9. customThe crude solid was recrystallized from a mixture of 30 mL each of ethanol and water

ORD record

ord-d0b79a38c5e04ce1bf0e5fc1e5abe20d

Source dataset

uspto-grants-2008_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07378415B2