92% |
With hydrazine hydrate; In ethanol; for 17h;Inert atmosphere; |
Toa stirred suspension of <strong>[2942-06-5]6-nitrobenzo[d]thiazole</strong> (4.234 g, 23.50 mmol) in EtOH(41 mL) was added hydrazine monohydrate (7.0 ml, 0.22 mol). The resultingblood-red solution was allowed to stir overnight for 17 h before diluting withH2O (50 mL). To this was added 1 M HCl until a pH of 2 was obtained,which afforded a bright yellow precipitate. This material was extracted intoDCM (5 x 10 mL), dried over Na2SO4, and concentratedunder reduced pressure to afford the title compound (3.716 g, 92%): 1HNMR (400 MHz, CDCl3) NMR (400 MHJ = 2.6 Hz, 1H), 8.05 - 7.99(m, 1H), 6.71 (d, J = 8.9 Hz, 1H), 5.12 - 4.88 (m, 2H), 3.01 (s, 1H).13C NMR (101 MHz, CDCl3) delta 153.54, 138.98, 132.05, 126.10,113.45, 110.96; LC/MS (ESI): Exact mass calcd. for C6H6N2O2S[M-H]-, 169.0072. Found 168.9980. |
86% |
With hydrazine; In ethanol; at 25℃; for 3h; |
A solution of <strong>[2942-06-5]<strong>[2942-06-5]6-nitrobenzothiazol</strong>e</strong> (5 g, 27.7 mmol) in ethanol (50 mL) was treated with mono hydrazine hydrate (19 g, 388 mmol). The reaction mixture was stirred for 3 h at 25 0C and concentrated in vacuo. The resulting red oil was taken up in ethyl acetate, carefully acidified with 0.1 M aqueous hydrochloric acid solution until the solution turned light yellow. The reaction mixture was extracted with ethyl acetate, dried over magnesium sulfate, filtered, and concentrated in vacuo. The <n="141"/>resulting orange solid was triturated with diethyl ether and dried in vacuo to afford the desired product, 2-amino-5-nitro-benzenethiol (4.1 g, 23.9 mmol, 86%) as a yellow solid. 1H NMR (400 MHz, Acetone-d6) delta 6.43 (bs, 2H), 6.82 (d, IH, / = 8.7 Hz), 7.65 (d, IH, / = 2.2 Hz), 7.88 (dd, IH, J1 = 8.9 Hz, J2 = 2.7 Hz). LC-MS (ESI) calcd for C6H6N2O2S [M+H+] 171.01, found 193.20 [M+Na+]. |
86% |
With hydrazine; In ethanol; at 25℃; for 3h; |
A solution of <strong>[2942-06-5]<strong>[2942-06-5]6-nitrobenzothiazol</strong>e</strong> (5 g, 27.7 mmol) in ethanol (50 mL) was treated with mono hydrazine hydrate (19 g, 388 mmol). The reaction mixture was stirred for 3 h at 25 0C and concentrated in vacuo. The resulting red oil was taken up in ethyl acetate, carefully acidified with 0.1 M aqueous hydrochloric acid solution until the solution turned light yellow. The reaction mixture was extracted with ethyl acetate, dried over magnesium sulfate, filtered, and concentrated in vacuo. The resulting orange solid was triturated with diethyl ether and dried in vacuo to afford the desired product, 2-amino-5-nitro-benzenethiol (4.1 g, 23.9 mmol, 86% yield) as a yellow solid. 1H NMR (400 MHz, Acetone-^) delta 6.43 (bs, 2H), 6.82 (d, IH, J= 8.7 Hz), 7.65 (d, IH, J= 2.2 Hz), 7.88 (dd, IH, J1 = 8.9 Hz, J2 = 2.7 Hz). LC-MS (ESI) calcd for C6H6N2O2S [M+H+] 171.01, found 193.20 [M+Na+] |
86% |
|
A solution of <strong>[2942-06-5]<strong>[2942-06-5]6-nitrobenzothiazol</strong>e</strong> 37 (5 g, 27.7 mmol) in 50 mL of ethanol was treated with hydrazine monohydrate (19 g, 388.0 mmol). The reaction mixture was stirred for 3 h at room temperature and concentrated in vacuo. The resulting red oil was taken up in ethyl acetate and carefully acidified with 0.1 N aqueous hydrochloric acid until the solution turned light yellow. The reaction mixture was extracted with ethyl acetate, dried with magnesium sulfate, filtered, and concentrated in vacuo. The resulting orange solid was triturated with diethyl ether and dried in vacuo to afford the title compound 38 (4.1 g, 86%) as a yellow solid. 1H NMR (400 MHz, Acetone-d6) delta 6.43 (bs, 2H), 6.82 (d, 1H, J=8.7 Hz), 7.65 (d, 1H, J=2.2 Hz), 7.88 (dd, 1H, J=8.9 Hz, J2 2.7 Hz). LC-MS calculated for C6-16N2O2S (M+H+): 171.01, found (M+Na+) 193.20. |
84% |
With hydrazine; In ethanol; for 2h;Heating / reflux; |
To a stirred solution of <strong>[2942-06-5]<strong>[2942-06-5]6-nitrobenzothiazol</strong>e</strong> (30 g, 0.1665 mol) in ethanol (500 mL) is added 100% hydrazine hydrate (60.2 mL, 1.931 mol). The mixture is refluxed for 2 h at which time the solution turns red. The reaction is quenched by the addition of ice cold conc. HCl until the red color disappears. The resulting solid is filtered, washed with water (25 mL) and dried under high vacuum to give the title compound as a yellow solid (28.96 g, 84 %), MS nilz 171.5 (M+H) +. |
84% |
With hydrazine; In ethanol; for 2h;Heating / reflux; |
Step 1: Preparation of 2-amino-5-nitrobenzenethiol To a stirred solution of <strong>[2942-06-5]<strong>[2942-06-5]6-nitrobenzothiazol</strong>e</strong> (30 g, 0.1665 mol) in ethanol (500 ML) is added 100% hydrazine hydrate (60.2 ML, 1.931 mol).The mixture is refluxed for 2 h at which time the solution turns red.The reaction is quenched by the addition of ice cold conc. HCl until the red color disappears.The resulting solid is filtered, washed with water (25 ML) and dried under high vacuum to give the title compound as a yellow solid (28.96 g, 84%), MS m/z 171.5 (M+H)+. |
|
With potassium hydroxide; ethanol; for 0.25h;Heating / reflux; |
Example 1; N-{3-[(S)-5-?e/t-Butyl-l-(3-chloro-4-fluoro-benzyl)-4-hydroxy-2-oxo-2,5-dihydro-lH- pyrrol-3-yl]-2-chloro-l,l-dioxo-l,4-dihydro-llambda 6 -benzo[l,4]thiazin-7-yl}- methanesulfonamide (1-9; see SCHEME 1); steps 1 and 2-; To a solution of <strong>[2942-06-5]<strong>[2942-06-5]6-nitrobenzothiazol</strong>e</strong> (10, 10.2 g, 57 mmol) in EtOH (500 mL) was added KOH (7.0 g, 125 mmol). The reaction was heated at reflux for 15 min then cooled to 0 C. Ethyl chloroaceto acetate (9.3 g, 57 mmol) was added and the mixture stirred at RT for 1 h. The reaction mixture was poured into IN HCl (500 mL) and the resulting solid was collected. The solid was dissolved in EtOAc. The organic phase was washed with brine, dried (MgSO4) and the solvent was removed under reduced pressure. The product was purified by SiO2 chromatography eluting with 10% EtOAc/hexane to afford 0.61 g (70%) of 12a: LCMS RT 3.48 min, M+H. |
|
With hydrazine hydrate; In ethanol; at 20℃; for 4h;Inert atmosphere; |
Examples 5 and 6; 5a to 5b; 2- Amino-5 -nitrobenzenethiol; To a solution of 6-Nitrobenzo[d] thiazole (5a) (10 g, 55.5 mmol) in EtOH (100 mL), Hydrazine hydrate (39 g, 77.9 mmol) was added at room temperature under nitrogen atmosphere. The reaction mixture was stirred at room temperature for 4 h. After completion of the reaction (by TLC) the volatiles were removed under reduced pressure, the residue was neutralized with IN HCl (100 mL) and extracted with EtOAc (3 x 150 mL). The combined organic extracts were dried over Na2S04 and concentrated under reduced pressure to afford 2-Amino-5-nitrobenzenethiol (5b) (7.0 g, crude). The crude material was taken to the next step without purification. TLC: 30% EtOAc/Hexane (Rf: 0.2) |
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With hydrazine hydrate; In ethanol; at 27℃; for 16h; |
Ethanol (50 mL) was stirred in <strong>[2942-06-5]6-nitrobenzo[d]thiazole</strong> was added (5.00 g, 27.3 mmol) hydrazine hydrate in suspension (8.00 mL, 137 mmol, 85%). The solution was stirred for 16 hours at 27 C produced as a result. The mixture was diluted with water (30 ml) and slowly acidified with HCl (3 N, 40 mL) and extracted with EtOAc (50 mL × 2). The combined organic layer was washed with brine (20 mL), and dried over anhydrous Na2SO4, and concentrated under reduced pressure to produce a E1. |