Water → 6-amino-3,4-dihydro-2H-1,4-benzothiazin-3-one

Temperature

80 °C

A mixture of iron (30.2 g, 540 mmol), glacial acetic acid (2 mL), and water (40 mL) was prepared in a 500 mL 3-necked round bottom flask equipped with a dropping funnel and an overhead stirrer. A solution of (2,4-dinitro-phenylsulfanyl)-acetic acid ethyl ester (11.79 g, 41.2 mmol) in glacial acetic acid (40 mL) and ethyl acetate (40 mL) was added dropwise. After addition the dropping funnel was replaced with a condenser and the solution heated at 80° C. for 3.5 hrs, then allowed to stir overnight at room temperature. The mixture was filtered through Celite and the Celite washed with ethyl acetate and water. The layers were separated in a separatory funnel and the aqueous layer extracted twice with ethyl acetate. The organic layers were washed with water, twice with saturated sodium bicarbonate, then dried over magnesium sulfate, filtered, and evaporated under vacuum to yield a 6-amino-4H-benzo[1,4]thiazin-3-one as a brown solid.

1. customwas prepared in a 500 mL 3-necked round bottom flask
2. customequipped with a dropping funnel and an overhead stirrer
3. additionAfter addition the dropping funnel
4. customwas replaced with a condenser
5. filtrationThe mixture was filtered through Celite
6. washthe Celite washed with ethyl acetate and water
7. customThe layers were separated in a separatory funnel
8. extractionthe aqueous layer extracted twice with ethyl acetate
9. washThe organic layers were washed with water, twice with saturated sodium bicarbonate
10. dry with materialdried over magnesium sulfate
11. filtrationfiltered
12. customevaporated under vacuum

ORD record

ord-ac7b2ae3477c40678b11dc07f85f9b40

Source dataset

uspto-grants-2005_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06858621B2