2,3-DIHYDRO-1,1-DIOXO-1,2-BENZISOTHIAZOLE

Step 1. Saccharin (10.0 g, 54.6 mmol) was slowly added to solution of LiAlHtetrahydrofuran (2 mL) was added drop-wise to a 0 °C suspension of lithium aluminum hydride (45.6 mg, 1.20 mmol) in tetrahydrofuran (3 mL). After the reaction mixture had stirred for 30 minutes at 0 °C, it was gradually warmed to 15 °C and stirred at 15 °C for 16 hours. The white suspension was treated with saturated aqueous ammonium chloride solution, and then extracted with ethyl acetate (20 mL). The organic layer was dried over sodium sulfate, filtered, and concentrated in vacuo to provide the product as a grey solid. Yield: 160 mg, 0.946 mmol, 87percent. Preparation 16 Example 82 Lithium aluminium hydride1 M in ether (4.09 mL) was addedslowly at 0 C to a solution of o-sulfobenzimide (7, 554 mg, 3.02 mmol) in THF (8.0 mL), and stirred for 48 min. Subsequently, sodium sulfate hydrate was added to the solution and filteredthrough Celite. The organic layer was concentrated in reducedpressure to afford the title compound (182 mg, 35.6percent); 1H NMR(400 MHz, CDCl3) d 7.85 (d, J = 7.7, 1H), 7.67 (dt, J = 7.5, 1.2 Hz, 1H), 7.58 (t, J = 7.4 Hz, 1H), 7.44 (d, J = 7.6 Hz, 1H), 4.74 (br, 1H), 4.59 (s, 2H).Step 1. Saccharin (10.0 g, 54.6 mmol) was slowly added to solution of LiAlH4 (2.24 g, 59.0 mmol) in 300 mL of THF at 0°C. The reaction mixture was stirred for 3h at 15°C under an inert atmosphere. Upon completion, EtOAc (100 mL) was slowly added followed by addition of 10percent H2S04 (lOOmL). The organic layer was separated and washed with 100 mL of 5percent sodium carbonate solution, dried over anhydrous sodium sulfate, filtered, and concentrated to give 1 (4.4 g, 97percent).tetrahydrofuran (2 mL) was added drop-wise to a 0 °C suspension of lithium aluminum hydride (45.6 mg, 1.20 mmol) in tetrahydrofuran (3 mL). After the reaction mixture had stirred for 30 minutes at 0 °C, it was gradually warmed to 15 °C and stirred at 15 °C for 16 hours. The white suspension was treated with saturated aqueous ammonium chloride solution, and then extracted with ethyl acetate (20 mL). The organic layer was dried over sodium sulfate, filtered, and concentrated in vacuo to provide the product as a grey solid. Yield: 160 mg, 0.946 mmol, 87percent. 1H NMR (400 MHz, CDCI3) delta 7.81 (d, J=7.8 Hz, 1 H), 7.63 (dd, half of ABX pattern, J=7.5, 7.3 Hz, 1 H), 7.54 (dd, half of ABX pattern, J=7.5, 7.5 Hz, 1 H), 7.41 (d, J=7.8 Hz, 1 H), 4.95-4.80 (br s, 1 H), 4.55 (s, 2H).Preparation 16 2, 3-Dihydrobenzo[d]isothiazole 1, 1-dioxide To a cold solution of lithium aluminum hydride (0.414 g) in anhydrous tetrahydrofuran (30 mL), kept at 0° C. with an external ice bath, was added sulfobenzimide (1 g, 5.5 mmol). The reaction was allowed to warm to ambient temperature and stirred overnight. The reaction was quenched with the addition of water and 2.5M aqueous sulfuric acid. The mixture was filtered through Celite and washed with ethyl acetate. The organic layer was washed with 1M aqueous sulfuric acid, dried (anhydrous magnesium sulfate), filtered, and concentrated to afford an off-white solid (0.75 g, 81percent). 1H NMR (CDCl3, 300 MHz) delta 7.81-7.78 (d, 1H, J=7.8 Hz), 7.64-7.59 (dt, 1H, J=1.2, 7.5 Hz), 7.52-7.49 (dt, 1H, J=0.75, 7.5 Hz), 7.41-7.37 (d, 1H, J=8.1 Hz), 4.8 (br s, 1H), 4.55-4.54 (d, 1H, J=3.6 Hz).Example 82 1, 2-Benzisothiazoline-1, 1-dioxide To a solution of 1, 2-benzisothiazoline-3-one-1, 1-dioxide (25, 554 mg, 3.02 mmol) in THF (8.0 mL) was slowly added lithium aluminum hydride (1M in ether, 4.09 mL, 4.09 mmol). The solution was stirred for 48 hrs, followed by the slow addition of drops of Na2SO4 10H2O at 0° C. The reaction mixture was filtered through celite, and the filtrate was concentrated to dryness to afford the title compound (182 mg, 35.6percent). 1H NMR (300 MHz, CDCl3) delta 7.85 (d, J=7.65 Hz, 1H), 7.67 (d, J=7.49, 1.17 Hz, 1H), 7.58 (t, J=7.44 Hz, 1H), 7.44 (d, J=7.59 Hz, 1H), 4.74 (brs, 1H), 4.59 (s, 2H)Lithium aluminium hydride1 M in ether (4.09 mL) was addedslowly at 0 C to a solution of o-sulfobenzimide (7, 554 mg, 3.02 mmol) in THF (8.0 mL), and stirred for 48 min. Subsequently, sodium sulfate hydrate was added to the solution and filteredthrough Celite. The organic layer was concentrated in reducedpressure to afford the title compound (182 mg, 35.6percent); 1H NMR(400 MHz, CDCl3) d 7.85 (d, J = 7.7, 1H), 7.67 (dt, J = 7.5, 1.2 Hz, 1H), 7.58 (t, J = 7.4 Hz, 1H), 7.44 (d, J = 7.6 Hz, 1H), 4.74 (br, 1H), 4.59 (s, 2H).General procedure: First weigh ferrous perchlorate (5.1 mg, 0.02 mmol) and ligand L2 (8.2 mg, 0.04 mmol) in a 4 mL reaction flask, and add 1.0 mL of acetonitrile to dissolve.After stirring at room temperature for 30 minutes, after in situ complexation, the molecular sieve (50.0 mg) was weighed.Iodobenzene pivalate (163.8 mg, 0.4 mmol) and p-grade phenylpropanesulfonamide substrate (42.3 mg, 0.2 mmol), Adding to the reaction system, adding 1.0 mL of acetonitrile to dissolve, and reacting at 80 C for 2 h.Filtration, the filter cake was washed with an appropriate amount of saturated sodium bicarbonate, and the aqueous phase was extracted with dichloromethane (3×10 mL).The organic phase is combined, washed with saturated brine and dried over anhydrous sodium sulfate.Column chromatography (dichloromethane / petroleum ether = 1:1 to dichloromethane), 3-(4-Methylphenyl)isothiazolidine 1, 1-dioxo (33.7 mg, 80%) was obtained as a white solid. (150 mg, 0.887 mmol), N-Boc-bromoethylamine (238mg, 1.064mmol) And cesium carbonate (867mg, 2.66mmol) in 5ml DMF, It was then stirred overnight. On the following day, after the reaction was detected by TLC, water was added for extraction. It was washed with saturated brine and dried over anhydrous sodium sulfate. Suction filtration, the filtrate was concentrated under reduced pressure, the crude product was separated by column chromatography, 124 mg of a white solid were obtained with a yield of 45%.General procedure: To the mixture of the precursor 10(2.26 g, 10.1 mmol, 1.5 equiv) and tert-butyl 1, 2, 5-thiadiazolidine-2-carboxylate 1, 1-dioxide (1.50 g, 6.75 mmol, 1.0 equiv) in dry DMF(10 mL), was added Cs2CO3 (6.60 g, 20.25 mmol, 3.0 equiv). Themixture was stirred at room temperature overnight, and thenextracted with ethyl acetate. The organic phase was washed withsaturated NaHCO3 and brine, dried over anhydrous Na2SO4, filteredand concentrated. The resulting residue was purified via silica gelchromatography to give 11a as colorless oil (1.96 g, 79%).

Molecular Weight:169.20
XLogP3:0.5
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:3
Exact Mass:169.01974964
Monoisotopic Mass:169.01974964
Topological Polar Surface Area:54.6
Heavy Atom Count:11
Complexity:242
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes