Sodium hydride → 2-Benzo[1,3]dioxol-5-ylmethyl-4-(benzo[1,3]dioxol-5-ylsulfanyl)-1,1-dioxo-1,2-dihydro-1lambda6-benzo[e][1,2]thiazine-3-carboxylic acid methyl ester

To 2-Benzo[1,3]dioxol-5-ylmethyl-4-hydroxy-1,1-dioxo-1,2-dihydro-1λ6 -benzo[e][1,2]thiazine-3-carboxylic acid methyl ester in dichloromethane (6 mL) and pyridine (0.65 mL, 7.75 mmol) was added trifluoromethanesulfonic anhydride (0.32 mL, 1.71 mmol). This mixture was stirred at room temperature for 30 minutes. Diluted with ethyl acetate (100 mL), washed with 1N HCl (2×50 mL), brine (50 mL), dried with magnesium sulfate and then evaporated in vacuo to afford the crude 2-benzo[1,3]dioxol-5-ylmethyl-6,7-dimethoxy-1,1-dioxo-4-(trifluoro-methanesulfonyloxy)-1,2-dihydro-1λ6 -benzo[e][1,2]thiazine-3-carboxylic acid methyl ester. A solution of this ester, in DMF (3 mL), was added to sodium 1,3-benzodioxole-5-thiolate (0.31 g, 2.0 mmol) {prepared by dissolving 1,3-benzodioxole-5-thiol (0.31 g, 2.0 mmol) in DMF (3 mL) and stirring with sodium hydride (0.081 g, 2.0 mmol) for 5 minutes} in DMF (3 mL). After stirring at room temperature for 16 hours the mixture was diluted with ethyl acetate (100 mL), washed with 1N NaOH(2×50 mL), brine (50 mL), dried with magnesium sulfate, and evaporated in vacuo. Silica gel column chromatography eluting with 25% ethyl acetate in hexane afforded the title compound as a foam (0.64 g, 79%);

1. customprepared
2. washwashed with 1N NaOH(2×50 mL), brine (50 mL)
3. dry with materialdried with magnesium sulfate
4. customevaporated in vacuo
5. washSilica gel column chromatography eluting with 25% ethyl acetate in hexane

ORD record

ord-f825727988ee479d87f64778546512dc

Source dataset

uspto-grants-1997_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05599811