3-bromo-1-methylpyrrole-2,5-dione

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Pursuant to steps a and b of Reaction Scheme 14, a solution of bromomaleic anhydride (52.8 g, 0.298 mol) in diethyl ether (250 mL) was cooled to 5° C. A 2 M solution of methylamine in THF (298 mL, 0.596 mol, 2 eq.) was added dropwise over 1 hour and the reaction stirred for a further 30 minutes, maintaining the temperature below 10° C. The resulting precipitate was filtered, washed with diethyl ether (2×100 mL) and air-dried for 30 minutes, then suspended in acetic anhydride (368 mL) and sodium acetate (12.2 g, 0.149 mol, 0.5 eq.) added. The reaction was heated to 60° C. for 2 hours and solvent was then removed in vacuo. The residue was taken up in DCM (500 mL) and washed with saturated sodium bicarbonate solution (2×500 mL) and water (2×300 mL). Organics were dried over MgSO4 (89 g), filtered and reduced in vacuo. The resulting oil was azeotroped with toluene (4×100 mL) to give N-methyl bromomaleimide as a beige solid. Yield=41.4 g (73%); 1H NMR (300 MHz, CDCl3) δ 6.95 (1H, s, CH), 3.07 (3H, s, NCH3). Pursuant to steps a and b of Reaction Scheme 14 maintaining the temperature below 10° C The resulting precipitate was filtered washed with diethyl ether (2×100 mL) air-dried for 30 minutes solvent was then removed in vacuo washed with saturated sodium bicarbonate solution (2×500 mL) and water (2×300 mL) Organics were dried over MgSO4 (89 g) filtered The resulting oil was azeotroped with toluene (4×100 mL)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To propylamine (52 μL, 0.78 mmol) and sodium acetate (64 mg, 0.78 mmol) in methanol (30 mL) was added N-methylmonobromomaleimide (150 mg, 0.78 mmol) dropwise in methanol (30 mL). After 10 minutes, solvent was removed in vacuo and purification by flash chromatography (10% ethyl acetate in petroleum ether) afforded the desired compound as a bright yellow waxy solid (41 mg, 0.24 mmol) in 31% yield. δH (500 MHz, CDCl3) 5.43 (s, 1H, NH), 4.80 (s, 1H, H-2), 3.16-3.13 (m, 2H, H2-9), 2.98 (s, 3H, H3-6), 1.71-1.64 (m, 2H, H2-8), 0.99 (t, J=7.5, H3-7); δC (125 MHz, CDCl3) 172.71 (C═O), 167.66 (C═O), 149.51 (C3), 83.84 (C2), 46.01 (C9), 23.44 (C6), 21.87 (C8), 11.38 (C7); IR (film, cm−1) 3317 (m), 2944 (w), 1698 (s), 1651 (s); MS (EI) m/z (relative intensity): 168 (M+, 70), 139 (100), 111 (40); Exact Mass Calcd for [C8H12N2O2]+ requires m/z 168.0893 Found 168.0887 (EI); UV (Acetonitrile) ε210=15900, ε240=2800, ε283=500 and ε368=500 cm−1M−1 d3. solvent was removed in vacuo and purification by flash chromatography (10% ethyl acetate in petroleum ether)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To N-methyl bromomaleimide (100 mg, 0.53 mmol) and sodium acetate trihydrate (70 mg, 0.53 mmol) in methanol (15 mL) was added hexanethiol (74 μL, 0.58 mmol) in methanol (100 mL) dropwise over 1 hour with vigorous stirring. After 5 minutes solvent was removed in vacuo. Purification by column chromatography (gradient elution in 10% ethyl acetate in petroleum ether to 30% ethyl acetate in petroleum ether) afforded the desired compound as a bright yellow solid (99 mg, 0.44 mmol) in 83% yield. δH (600 MHz, CDCl3) 6.03 (s, 1H, H-2), 3.01 (s, 3H, H3-5), 2.89 (t, 2H, J=7.6, 2H, H2-11), 1.76-1.71 (m, 2H, H2-10), 1.46-1.41 (m, 2H, H2-9), 1.33-1.27 (m, 4H, H2-7 and CH2-8), 0.89 (t, 3H, J=6.5, H3-6); δC (125 MHz, CDCl3) 171.47 (C═O), 169.94 (C═O), 151.84 (C3), 117.27 (C2), 31.92 (C11), 31.31 (CH2), 28.64 (CH2), 27.75 (CH2), 24.10 (C5), 24.10 (C7), 14.09 (C6); IR (oil, cm−1) 2727 (w), 1708 (s); MS (FAB+) m/z (relative intensity): 250 ([M+Na], 40), 228 (35), 199 (30), 176 (100); Exact Mass Calcd for [C11H17NO2S]+Na requires m/z 250.0878 Found 250.0880 (FAB+). After 5 minutes solvent was removed in vacuo Purification by column chromatography (gradient elution in 10% ethyl acetate in petroleum ether to 30% ethyl acetate in petroleum ether)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To N-methyl bromomaleimide (100 mg, 0.53 mmol) and sodium acetate trihydrate (70 mg, 0.53 mmol) in methanol (15 mL) was added hexanethiol (74 μL, 0.58 mmol) in methanol (100 mL) dropwise over 1 hour with vigorous stirring. After 5 minutes solvent was removed in vacuo. Purification by column chromatography (gradient elution in 10% ethyl acetate in petroleum ether to 30% ethyl acetate in petroleum ether) afforded the desired compound as a bright yellow solid (99 mg, 0.44 mmol) in 83% yield. δH (600 MHz, CDCl3) 6.03 (s, 1H, H-2), 3.01 (s, 3H, H3-5), 2.89 (t, 2H, J=7.6, 2H, H2-11), 1.76-1.71 (m, 2H, H2-10), 1.46-1.41 (m, 2H, H2-9), 1.33-1.27 (m, 4H, H2-7 and CH2-8), 0.89 (t, 3H, J=6.5, H3-6); δC (125 MHz, CDCl3) 171.47 (C═O), 169.94 (C═O), 151.84 (C3), 117.27 (C2), 31.92 (C11), 31.31 (CH2), 28.64 (CH2), 27.75 (CH2), 24.10 (C5), 24.10 (C7), 14.09 (C6); IR (oil, cm−1) 2727 (w), 1708 (s); MS (FAB+) m/z (relative intensity): 250 ([M+Na], 40), 228 (35), 199 (30), 176 (100); Exact Mass Calcd for [C11H17NO2S]+Na requires m/z 250.0878 Found 250.0880 (FAB+). After 5 minutes solvent was removed in vacuo Purification by column chromatography (gradient elution in 10% ethyl acetate in petroleum ether to 30% ethyl acetate in petroleum ether)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To N-methylmaleimide (0.5 g, 4.5 mmol) in methanol (10 mL) was added bromine (232 μL, 4.5 mmol) dropwise in methanol (5 mL). The reaction mixture was stirred at room temperature for 12 hours. The solvent was removed in vacuo and dissolved in tetrahydrofuran (20 mL). Triethylamine (815 μL, 5.9 mmol) in tetrahydrofuran (5 mL) was added over 5 minutes, whereupon a precipitate formed. The reaction mixture was stirred for 24 hours. The solid was filtered off and washed with tetrahydrofuran (50 mL). Purification by flash chromatography (10% ethyl acetate in petroleum ether) afforded the desired compound as a pale yellow powder (563 mg, 2.96 mmol) in 66% yield. δH (500 MHz, CDCl3) 6.90 (s, 1H, H-3), 3.09 (s, 3H, H3-6); δC (125 MHz, CDCl3) 168.6 (C═O), 165.4 (C═O), 131.9 (C3), 131.4 (C2), 24.7 (C6); IR (solid, cm−1) 3106 (s), 1708 (s); MS (CI+) m/z, (relative intensity): 192 ([81M+H], 99), 190([79M+H], 100); Exact mass calcd for [C5H4O2N79Br]+H requires 189.9504 Found 189.9505 (CI+); m.p: 77-79° C.; UV (Acetonitrile) ε209=17100, ε238=13200, ε299=290 cm−1M−1 d3. The solvent was removed in vacuo dissolved in tetrahydrofuran (20 mL) formed The reaction mixture was stirred for 24 hours The solid was filtered off washed with tetrahydrofuran (50 mL) Purification by flash chromatography (10% ethyl acetate in petroleum ether)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To N-methyl maleimide (0.5 g, 4.5 mmol) in methanol (22.5 mL) was added bromine (0.52 mL, 10 mmol) dropwise. The reaction mixture was stirred at room temperature for 24 hours. Solvent was removed in vacuo and the reaction mass was dissolved in tetrahydrofuran (20 mL) and triethylamine (0.8 mL, 5.85 mmol) added, then stirred for 24 hours at room temperature. The material was purified by flash chromatography on silica gel (petroleum ether: ethyl acetate, 7:3) to afford a pale white powder (0.761 g, 4.0 mmol) in 89% yield. Solvent was removed in vacuo the reaction mass was dissolved in tetrahydrofuran (20 mL) stirred for 24 hours at room temperature The material was purified by flash chromatography on silica gel (petroleum ether: ethyl acetate, 7:3)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To N-methyl maleimide (0.5 g, 4.5 mmol) in methanol (22.5 mL) was added bromine (0.52 mL, 10 mmol) dropwise. The reaction mixture was stirred at room temperature for 24 hours. Solvent was removed in vacuo and the reaction mass was dissolved in tetrahydrofuran (20 mL) and triethylamine (0.8 mL, 5.85 mmol) added, then stirred for 24 hours at room temperature. The material was purified by flash chromatography on silica gel (petroleum ether: ethyl acetate, 7:3) to afford a pale white powder (0.761 g, 4.0 mmol) in 89% yield. Solvent was removed in vacuo the reaction mass was dissolved in tetrahydrofuran (20 mL) stirred for 24 hours at room temperature The material was purified by flash chromatography on silica gel (petroleum ether: ethyl acetate, 7:3)

反応条件: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Pursuant to steps a and b of Reaction Scheme 14, a solution of bromomaleic anhydride (52.8 g, 0.298 mol) in diethyl ether (250 mL) was cooled to 5° C. A 2 M solution of methylamine in THF (298 mL, 0.596 mol, 2 eq.) was added dropwise over 1 hour and the reaction stirred for a further 30 minutes, maintaining the temperature below 10° C. The resulting precipitate was filtered, washed with diethyl ether (2×100 mL) and air-dried for 30 minutes, then suspended in acetic anhydride (368 mL) and sodium acetate (12.2 g, 0.149 mol, 0.5 eq.) added. The reaction was heated to 60° C. for 2 hours and solvent was then removed in vacuo. The residue was taken up in DCM (500 mL) and washed with saturated sodium bicarbonate solution (2×500 mL) and water (2×300 mL). Organics were dried over MgSO4 (89 g), filtered and reduced in vacuo. The resulting oil was azeotroped with toluene (4×100 mL) to give N-methyl bromomaleimide as a beige solid. Yield=41.4 g (73%); 1H NMR (300 MHz, CDCl3) δ 6.95 (1H, s, CH), 3.07 (3H, s, NCH3). Pursuant to steps a and b of Reaction Scheme 14 maintaining the temperature below 10° C The resulting precipitate was filtered washed with diethyl ether (2×100 mL) air-dried for 30 minutes solvent was then removed in vacuo washed with saturated sodium bicarbonate solution (2×500 mL) and water (2×300 mL) Organics were dried over MgSO4 (89 g) filtered The resulting oil was azeotroped with toluene (4×100 mL)

反応条件: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Pursuant to steps a and b of Reaction Scheme 14, a solution of bromomaleic anhydride (52.8 g, 0.298 mol) in diethyl ether (250 mL) was cooled to 5° C. A 2 M solution of methylamine in THF (298 mL, 0.596 mol, 2 eq.) was added dropwise over 1 hour and the reaction stirred for a further 30 minutes, maintaining the temperature below 10° C. The resulting precipitate was filtered, washed with diethyl ether (2×100 mL) and air-dried for 30 minutes, then suspended in acetic anhydride (368 mL) and sodium acetate (12.2 g, 0.149 mol, 0.5 eq.) added. The reaction was heated to 60° C. for 2 hours and solvent was then removed in vacuo. The residue was taken up in DCM (500 mL) and washed with saturated sodium bicarbonate solution (2×500 mL) and water (2×300 mL). Organics were dried over MgSO4 (89 g), filtered and reduced in vacuo. The resulting oil was azeotroped with toluene (4×100 mL) to give N-methyl bromomaleimide as a beige solid. Yield=41.4 g (73%); 1H NMR (300 MHz, CDCl3) δ 6.95 (1H, s, CH), 3.07 (3H, s, NCH3). Pursuant to steps a and b of Reaction Scheme 14 maintaining the temperature below 10° C The resulting precipitate was filtered washed with diethyl ether (2×100 mL) air-dried for 30 minutes solvent was then removed in vacuo washed with saturated sodium bicarbonate solution (2×500 mL) and water (2×300 mL) Organics were dried over MgSO4 (89 g) filtered The resulting oil was azeotroped with toluene (4×100 mL)

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A 15 mmol solution of 3-bromo-2,5-furanedione and 15 mmol of methylamine at 40% in water, in 300 ml of glacial acetic acid is carried under reflux for 16 hours. After having allowed the reaction mixture to return to ambient temperature, 20 ml of acetic anhydride are added. The reaction medium is again brought to reflux under stirring for 4 hours before evaporating the solvents under reduced pressure. The expected product is obtained after purification by silica gel chromatography (heptane/ethyl acetate: 1/1) and recrystallization in ethanol. under reflux for 16 hours to return to ambient temperature to reflux before evaporating the solvents under reduced pressure