7-fluoro-1,1-dioxo-4H-1lambda6,2,4-benzothiadiazin-3-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: After suspending 7-fluoro-2H,4H-benzo[e]1,2,4-thiadiazine-1,1,3-trione (3.00 g, 13.9 mmol) in 50% sulfuric acid (90 mL), the mixture was stirred at 130° C. for 1 hour. The reaction mixture was cooled in an ice bath while adding 40% aqueous sodium hydroxide for neutralization. The aqueous solution was concentrated under reduced pressure to 200 mL, and the precipitate was filtered out. It was then suspended in ethyl acetate (100 mL), and the insoluble portion was filtered out. The filtrate was concentrated under reduced pressure and dried to obtain 2-amino-5-fluorobenzenesulfonamide. The reaction mixture was cooled in an ice bath The aqueous solution was concentrated under reduced pressure to 200 mL the precipitate was filtered out the insoluble portion was filtered out The filtrate was concentrated under reduced pressure dried

Conditions: temp:-80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: After dissolving chlorosulfonyl isocyanate (3.29 mL, 37.8 mmol) in nitroethane (45 mL), the mixture was cooled to −80° C. A solution of 4-fluoroaniline (3.50 g, 31.5 mmol) in nitromethane (5 mL) was then added dropwise thereto over a period of 10 minutes. The reaction mixture was raised to 0° C., and aluminum chloride (5.33 g, 40.0 mmol) was added. After heating to reflux for 30 minutes, the reaction mixture was cooled to room temperature and poured into ice water (120 mL). The precipitated crystals were filtered out and dried to obtain 7-fluoro-2H,4H-benzo[e]1,2,4-thiadiazine-1,1,3-trione. The reaction mixture was raised to 0° C. After heating to reflux for 30 minutes the reaction mixture was cooled to room temperature The precipitated crystals were filtered out dried

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: After suspending 7-fluoro-2H,4H-benzo[e]1,2,4-thiadiazine-1,1,3-trione (3.00 g, 13.9 mmol) in 50% sulfuric acid (90 mL), the mixture was stirred at 130° C. for 1 hour. The reaction mixture was cooled in an ice bath while adding 40% aqueous sodium hydroxide for neutralization. The aqueous solution was concentrated under reduced pressure to 200 mL, and the precipitate was filtered out. It was then suspended in ethyl acetate (100 mL), and the insoluble portion was filtered out. The filtrate was concentrated under reduced pressure and dried to obtain 2-amino-5-fluorobenzenesulfonamide. The reaction mixture was cooled in an ice bath The aqueous solution was concentrated under reduced pressure to 200 mL the precipitate was filtered out the insoluble portion was filtered out The filtrate was concentrated under reduced pressure dried

Conditions: temp:-80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: After dissolving chlorosulfonyl isocyanate (3.29 mL, 37.8 mmol) in nitroethane (45 mL), the mixture was cooled to −80° C. A solution of 4-fluoroaniline (3.50 g, 31.5 mmol) in nitromethane (5 mL) was then added dropwise thereto over a period of 10 minutes. The reaction mixture was heated to 0° C., and aluminum chloride (5.33 g, 40.0 mmol) was added. After heating to reflux for 30 minutes, the reaction mixture was cooled to room temperature and then poured into ice water (120 mL). The precipitated crystals were filtered out and dried to obtain 7-fluoro-2H,4H-benzo[e]1,2,4-thiadiazine-1,1,3-trione. The reaction mixture was heated to 0° C. After heating to reflux for 30 minutes the reaction mixture was cooled to room temperature The precipitated crystals were filtered out dried