2(3H)-Benzothiazolethione,5-nitro-(9CI)

5-Mtro-2-mercapto benzothiazole (12): A mixture of 2-fluoro-5-nitro aniline (11, 1.00 g, 6.40 mmol) and potassium O-ethyl dithiocarbonate (1.53 g, 9.60 mmol) inDMF (15 mL) was heated overnight at 110-110 To a solution of 2-fluoro-5-nitroaniline (3.12 g, 20 mmol) in DMF (15 mL) potassium ethyl xanthogenate (3.93 g, 24 mmol) was added. The mixture was stirred at 100°C for 5 h before it was cooled to rt, diluted with water (25 mL) and 1 M aq. HCI (35 mL). The precipitate that formed was collected, washed with water (15 mL) and dried to give the title compound (or tautomer) (3.99 g) as a beige solid; LC-MS: t5-nitro-2-fluoroaniline (200 mg, 1.28 mmol)And sodium ethyl xanthate (250 mg, 1.73 mmol)Was dissolved in dry DMF (10 mL)Solution, nitrogen protection to warm up to 100 reaction 4h.After completion of the reaction, the temperature was lowered to room temperature, Slowly add water (10 mL) and 1 M / L hydrochloric acid solution (10 mL)Precipitation of solid, continue stirring 30min, Suction filtration, solid water washing, The filter cake was then dissolved with ethyl acetate, Dried over anhydrous sodium sulfate and concentrated under reduced pressure to give a tan solid product which was used directly in the next step.(180 mg, 66.3percent);General procedure: GP3-1: A solution of 2-halo substituted aniline (1.0 eq), potassium ethyl xanthate (1.2 eq or 2.2 eq, typically 2.2 eq) in 10 volume of anhydrous DMF was heated at 100 General procedure: GP3-1: A solution of 2-halo substituted aniline (1.0 eq), potassium ethyl xanthate (1.2 eq or 2.2 eq, typically 2.2 eq) in 10 volume of anhydrous DMF was heated at 100 0Cor 120 0C for 4 hours under nitrogen. TLC monitored the progress ofreaction. After completion, the reaction mixture was cooled to room temperature, diluted with water (10 volume) and neutralized by 1 M HCl solution to pH 5. Theformed precipitate was collected by filtration, rinsed with water, firstlydried by rotavapor, and then dried by oil pump to afford 2-mercaptobenzothiazole.GP3-2: 2-mercaptobenzothiazole in 10 volume ofanhydrous DCM, was added by sulfuryl chloride (SO2Cl2, 1volume) under ice-cooled condition. The mixture was stirred at rt for 1 hour, which was monitored by TLC. After consumption of starting material, the mixturewas diluted by 30 volume of ether, following quenching carefully by addingwater. Stirring was kept for 1 hour to make sure the SO2Cl2was totally consumed and product was released. Organic layer was collected, neutralized by saturated NaHCO3, dried over Na2SO4and purified by silica gel chromatograph to give the pure product, which wasfinally characterized by LC-MS and NMR.Solid General procedure: GP3-1: A solution of 2-halo substituted aniline (1.0 eq), potassium ethyl xanthate (1.2 eq or 2.2 eq, typically 2.2 eq) in 10 volume of anhydrous DMF was heated at 100 0Cor 120 0C for 4 hours under nitrogen. TLC monitored the progress ofreaction. After completion, the reaction mixture was cooled to room temperature, diluted with water (10 volume) and neutralized by 1 M HCl solution to pH 5. Theformed precipitate was collected by filtration, rinsed with water, firstlydried by rotavapor, and then dried by oil pump to afford 2-mercaptobenzothiazole.GP3-2: 2-mercaptobenzothiazole in 10 volume ofanhydrous DCM, was added by sulfuryl chloride (SO2Cl2, 1volume) under ice-cooled condition. The mixture was stirred at rt for 1 hour, which was monitored by TLC. After consumption of starting material, the mixturewas diluted by 30 volume of ether, following quenching carefully by addingwater. Stirring was kept for 1 hour to make sure the SO2Cl2was totally consumed and product was released. Organic layer was collected, neutralized by saturated NaHCO3, dried over Na2SO4and purified by silica gel chromatograph to give the pure product, which wasfinally characterized by LC-MS and NMR.Solid 5-Mtro-2-mercapto benzothiazole (12): A mixture of 2-fluoro-5-nitro aniline (11, 1.00 g, 6.40 mmol) and potassium O-ethyl dithiocarbonate (1.53 g, 9.60 mmol) inDMF (15 mL) was heated overnight at 110-110 0C under N2. After cooling, the reaction mixture was diluted with water and acidified with IN HCl. The precipitate was collected by filtration, washed with water, and dried under vacuum to yield compound 12 (1.27 g, 94%).To a solution of 2-fluoro-5-nitroaniline (3.12 g, 20 mmol) in DMF (15 mL) potassium ethyl xanthogenate (3.93 g, 24 mmol) was added. The mixture was stirred at 100C for 5 h before it was cooled to rt, diluted with water (25 mL) and 1 M aq. HCI (35 mL). The precipitate that formed was collected, washed with water (15 mL) and dried to give the title compound (or tautomer) (3.99 g) as a beige solid; LC-MS: tR= 0.76 min; [M+H]+= not detectable;1H NMR (400 MHz, D6-DMSO) delta: 14.17 (s, 1 H), 8.15 (dd, J, = 2.2 Hz, J2= 8.8 Hz, 1 H), 7.99 (d, J = 9.0 Hz), 7.97 (d, J = 2.3 Hz).5-nitro-2-fluoroaniline (200 mg, 1.28 mmol)And sodium ethyl xanthate (250 mg, 1.73 mmol)Was dissolved in dry DMF (10 mL)Solution, nitrogen protection to warm up to 100 reaction 4h.After completion of the reaction, the temperature was lowered to room temperature, Slowly add water (10 mL) and 1 M / L hydrochloric acid solution (10 mL)Precipitation of solid, continue stirring 30min, Suction filtration, solid water washing, The filter cake was then dissolved with ethyl acetate, Dried over anhydrous sodium sulfate and concentrated under reduced pressure to give a tan solid product which was used directly in the next step.(180 mg, 66.3%);

Molecular Weight:212.3
XLogP3:2.2
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:4
Exact Mass:211.97141972
Monoisotopic Mass:211.97141972
Topological Polar Surface Area:115
Heavy Atom Count:13
Complexity:253
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes