3-aminopiperidine-2,6-dione;hydrochloride

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

Procedure: A mechanically stirred mixture of 4-bromo-2-bromomethyl-benzoic acid methyl ester (121 g, 390 mmol) and 3-amino-piperidine-2,6-dione hydrochloride (64.2 g, 390 mmol) in DMF (400 mL) was treated dropwise with triethylamine (98.5 g, 980 mmol) over 75 minutes. After the addition was completed, the reaction mixture was stirred at room temperature overnight. The mixture was quenched sequentially with acetic acid (50 mL), water (2500 mL) and a 1:1 mixture of ethyl acetate and hexanes (600 mL). After stirring the mixture for 20 minutes, the solid was filtered, washed with water and air dried overnight. The solid was stirred in acetic acid (200 mL) and refluxed for 2 hours. The mixture was cooled to room temperature and filtered. The solid was washed with additional acetic acid, hexanes and air dried overnight to give 25.4 g of 3-(5-bromo-1-oxo-1,3-dihydro-isoindol-2-yl)-piperidine-2,6-dione as a grey solid, in 20% yield; 1H NMR (DMSO-d6) δ 1.97-2.04 (m, 1H), 2.32-2.46 (m, 1H), 2.56-2.63 (m, 1H), 2.85-2.97 (m, 1H), 4.34 (d, J=17.7 Hz, 1H), 4.47 (d, J=17.7 Hz, 1H), 5.11 (dd, J=13.2 Hz, J=5.1 Hz, 1H), 7.67 (d, J=8.1 Hz, 1H), 7.72 (dd, J=8.1 Hz, J=1.5 Hz, 1H), 7.89 (d, J=0.9 Hz, 1H), 11.00 (s, 1H). After the addition The mixture was quenched sequentially with acetic acid (50 mL), water (2500 mL) a 1:1 mixture of ethyl acetate and hexanes (600 mL) After stirring the mixture for 20 minutes the solid was filtered washed with water and air dried overnight The solid was stirred in acetic acid (200 mL) refluxed for 2 hours The mixture was cooled to room temperature filtered The solid was washed with additional acetic acid, hexanes and air dried overnight

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

Procedure: A mixture of 4-bromophthalic anhydride (10.0 g, 44.1 mmol), rac-α-aminoglutarimide hydrochloride (7.25 g, 44.0 mmol) and sodium acetate (3.61 g, 44.0 mmol) in acetic acid (150 mL) was heated to reflux overnight. The reaction mixture was cooled to room temperature, and the solvent was evaporated under vacuum. The residue was stirred in water (170 mL) for 3 hours, and the resulting solid was filtered, washed with additional water (80 mL), and dried under vacuum, to afford 13.8 g of 5-bromo-2-(2,6-dioxo-piperidin-3-yl)-isoindole-1,3-dione, in 93% yield; 1H NMR (DMSO-d6) δ 2.03-2.10 (m, 1H), 2.43-2.63 (m, 2H), 2.82-2.97 (m, 1H), 5.17 (dd, J=12.8 Hz, J=5.3 Hz, 1H), 7.85-7.88 (d, J=7.9 Hz, 1H), 8.10 (dd, J=7.9 Hz, J=1.7 Hz, 1H), 8.16 (d, J=1.7 Hz, 1H), 11.15 (s, 1H); 13C NMR (DMSO-d6) δ 21.9, 30.9, 49.2, 125.3, 126.4, 128.5, 130.1, 133.2, 137.6, 165.9, 166.4, 169.7, 172.7; Anal. Calcd for C13H9N2O4Br: C, 46.32; H, 2.69; N, 8.31. Found: C, 46.23; H, 2.47; N, 8.41. was heated to reflux overnight the solvent was evaporated under vacuum the resulting solid was filtered washed with additional water (80 mL) dried under vacuum

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

Procedure: A stirred mixture of 3-[(t-butoxycarbonyl-methyl-amino)-methyl]-phthalic acid (2.3 g, 7.1 mmol) from above and α-aminoglutarimide hydrochloride (1.3 g, 7.8 mmol) in pyridine (40 mL) was refluxed for 5 hours. The mixture was cooled and concentrated in vacuo. The residue was dissolved in EtOAc (100 mL) and water (50 mL). The EtOAc solution was separated and washed with water (40 mL), IN citric acid (2×40 mL), water (2×40 mL), and brine (40 mL), and then dried (MgSO4). Solvent was removed in vacuo, and the residue was purified by flash chromatography (SiO2, CH2Cl2: EtOAc 8:2) to give [2-(2,6-dioxo-piperidin-3-yl)-1,3-dioxo-2,3-dihydro-1H-isoindol-4-ylmethyl]-methyl-carbamic acid t-butyl ester (1.7 g, 60%): mp 138-140° C.; 1H NMR (DMSO-d6) δ 11.14 (s, 1H), 7.91-7.81 (m, 2H), 7.57 (b, 1H), 5.19-5.12 (dd, J=5.3 and 12.6 Hz, 1H), 4.85 (s, 2H), 2.97-2.83 (m, 1H), 2.89 (s, 3H), 2.63-2.50 (m, 2H), 2.07-2.03 (m, 1H), 1.44-1.29 (d, 9H); 13CNMR (DMSO-d6) δ 172.70, 169.74, 167.48, 166.87, 154.75, 138.31, 134.99, 132.31, 131.74, 127.42, 121.98, 79.13, 48.86, 47.32, 34.84, 30.90, 27.93, 21.94; Anal. Calcd. for C20H23N3O6: C, 59.84; H, 5.78; N, 10.47. Found: C, 59.51; H, 5.68; N, 10.31. was refluxed for 5 hours The mixture was cooled concentrated in vacuo The residue was dissolved in EtOAc (100 mL) The EtOAc solution was separated washed with water (40 mL), IN citric acid (2×40 mL) water (2×40 mL), and brine (40 mL), and then dried (MgSO4) Solvent was removed in vacuo the residue was purified by flash chromatography (SiO2, CH2Cl2: EtOAc 8:2)

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

Procedure: A stirred mixture of 3-[(t-butoxycarbonyl-methyl-amino)-methyl]-phthalic acid (2.3 g, 7.1 mmol) from above and α-aminoglutarimide hydrochloride (1.3 g, 7.8 mmol) in pyridine (40 mL) was refluxed for 5 hours. The mixture was cooled and concentrated in vacuo. The residue was dissolved in EtOAc (100 mL) and water (50 mL). The EtOAc solution was separated and washed with water (40 mL), IN citric acid (2×40 mL), water (2×40 mL), and brine (40 mL), and then dried (MgSO4). Solvent was removed in vacuo, and the residue was purified by flash chromatography (SiO2, CH2Cl2: EtOAc 8:2) to give [2-(2,6-dioxo-piperidin-3-yl)-1,3-dioxo-2,3-dihydro-1H-isoindol-4-ylmethyl]-methyl-carbamic acid t-butyl ester (1.7 g, 60%): mp 138-140° C.; 1H NMR (DMSO-d6) δ 11.14 (s, 1H), 7.91-7.81 (m, 2H), 7.57 (b, 1H), 5.19-5.12 (dd, J=5.3 and 12.6 Hz, 1H), 4.85 (s, 2H), 2.97-2.83 (m, 1H), 2.89 (s, 3H), 2.63-2.50 (m, 2H), 2.07-2.03 (m, 1H), 1.44-1.29 (d, 9H); 13CNMR (DMSO-d6) δ 172.70, 169.74, 167.48, 166.87, 154.75, 138.31, 134.99, 132.31, 131.74, 127.42, 121.98, 79.13, 48.86, 47.32, 34.84, 30.90, 27.93, 21.94; Anal. Calcd. for C20H23N3O6: C, 59.84; H, 5.78; N, 10.47. Found: C, 59.51; H, 5.68; N, 10.31. was refluxed for 5 hours The mixture was cooled concentrated in vacuo The residue was dissolved in EtOAc (100 mL) The EtOAc solution was separated washed with water (40 mL), IN citric acid (2×40 mL) water (2×40 mL), and brine (40 mL), and then dried (MgSO4) Solvent was removed in vacuo the residue was purified by flash chromatography (SiO2, CH2Cl2: EtOAc 8:2)

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

Procedure: This compound can be prepared according to the methods described in U.S. Pat. Nos. 6,281,230 and 5,635,517, the entireties of which are incorporated herein by reference. For example, the compound can be prepared through catalytic hydrogenation of 3-(4-nitro-1-oxo-1,3 dihydro-isoindol-2-yl)-piperidine-2,6-dione. 3-(4-Nitro-1-oxo-1,3 dihydro-isoindol-2-yl)-piperidine-2,6-dione can be obtained by allowing 2,6-dioxopiperidin-3-ammonium chloride to react with methyl 2-bromomethyl-4-nitrobenzoate in dimethylformamide in the presence of triethylamine. The methyl 2-bromomethyl-4-nitrobenzoate in turn is obtained from the corresponding methyl ester of nitro-ortho-toluic acid by conventional bromination with N-bromosuccinimide under the influence of light.

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

Procedure: A mixture of 16.25 g of 2,6-dioxopiperidin-3-ammonium chloride, and 30.1 g of methyl 2-bromomethyl-3,4,5,6-tetrafluorobenzoate, and 12.5 g of triethylamine in 100 mL of dimethylformamide is stirred at room temperature for 15 hours. The mixture is then concentrated in vacuo and the residue mixed with methylene chloride and water. The aqueous layer is separated and back-extracted with methylene chloride. The combined methylene chloride solutions are dried over magnesium sulfate and concentrated in vacuo to give 1-oxo-2-(2,6-dioxopiperidin-3-yl)-4,5,6,7-tetrafluoroisoindoline. The mixture is then concentrated in vacuo the residue mixed with methylene chloride and water The aqueous layer is separated back-extracted with methylene chloride The combined methylene chloride solutions are dried over magnesium sulfate concentrated in vacuo

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

Procedure: A mixture of 4-nitrophthalic anhydride (1.7 g, 8.5 mmol), α-aminoglutarimide hydrochloride (1.4 g, 8.5 mmol) and sodium acetate (0.7 g, 8.6 mmol) in glacial acetic acid (30 mL) was heated under reflux for 17 hours. The mixture was concentrated in vacuo and the residue was stirred with methylene chloride (40 mL) and water (30 mL). The aqueous layer was separated, extracted with methylene chloride (2×40 mL). The combined methylene chloride solutions were dried over magnesium sulfate and concentrated in vacuo to give 1.4 g (54%) of 1,3-dioxo-2-(2,6-dioxopiperidin-3-yl)-5-nitroisoindoline as a light brown solid. An analytical sample was obtained by recrystallization from methanol: mp 228.5-229.5° C.; 1H NMR (DMSO-d6) δ11.18(s, 1H), 8.69-8.65(d,d J=1.9 and 8.0 Hz, 1H), 8.56(d, J=1.9 Hz, 1H), 8.21(d, H=8.2 Hz, 1H), 5.28(d,d J=5.3 and 12.8 Hz, 1H), 2.93-2.07(m, 4H); 13C NMR (DMSO-d6) δ172.66, 169.47, 165.50, 165.23, 151.69, 135.70, 132.50, 130.05, 124.97, 118.34, 49.46, 30.85, 21.79; Anal. Calcd for C13H9N3O6: C, 51.49; H, 2.99; N, 13.86. Found: C, 51.59; H, 3.07; N, 13.73. was heated under reflux for 17 hours The mixture was concentrated in vacuo The aqueous layer was separated extracted with methylene chloride (2×40 mL) The combined methylene chloride solutions were dried over magnesium sulfate concentrated in vacuo

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

Procedure: This compound can be prepared according to the methods described in U.S. Pat. Nos. 6,281,230 and 5,635,517, the entireties of which are incorporated herein by reference. For example, the compound can be prepared through catalytic hydrogenation of 3-(4-nitro-1-oxo-1,3 dihydro-isoindol-2-yl)-piperidine-2,6-dione. 3-(4-Nitro-1-oxo-1,3 dihydro-isoindol-2-yl)-piperidine-2,6-dione can be obtained by allowing 2,6-dioxopiperidin-3-ammonium chloride to react with methyl 2-bromomethyl-4-nitrobenzoate in dimethylformamide in the presence of triethylamine. The methyl 2-bromomethyl-4-nitrobenzoate in turn is obtained from the corresponding methyl ester of nitro-ortho-toluic acid by conventional bromination with N-bromosuccinimide under the influence of light.

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

Procedure: To a stirred solution of 3-pentylamino-phthalic acid (2.51 g, 10 mmol) in acetic acid (50 ml) was added 3-amino-piperidine-2,6-dione hydrochloride (1.81 g, 11 mmol). The reaction mixture was heated to reflux overnight. The solvent was evaporated in vacuo and the residue dissolved in ethyl acetate (100 ml). The ethyl acetate mixture was washed with water (2×100 ml), saturated aqueous sodium bicarbonate (2×100 ml), brine (1×100 ml), and dried (MgSO4). The solvent was evaporated in vacuo and the solid residue was purified by chromatography (25% ethyl acetate/hexane) to give 1.82 g (53%) of product as a yellow solid: mp 141-143° C.; 1H NMR (DMSO-d6) d 11.09 (s, 1H); 7.58 (t, J=8.3 Hz, 1H), 7.08 (d, J=8.6 Hz, 1H), 7.02 (d, J=7.0 Hz, 1H), 6.519 (t, J=5.7 Hz, 1H), 5.06 (dd, J=5.3 and 12.4 Hz, 1H), 3.32-3.25 (m, 2H), 2.97-2.82 (m, 1H), 2.62-2.46 (m, 2H), 2.06-2.01 (m, 1H), 1.61-1.55 (m, 2H), 1.35-1.32 (m, 4H), 0.88 (t, J=6.7 Hz, 3H); 13C NMR (DMSO-d6) d 172.72, 170.01, 168.92, 167.25, 146.39, 136.21, 132.14, 117.08, 110.31, 108.99, 48.52, 41.77, 30.94, 28.46, 28.33, 22.12, 21.82, 13.85; Anal. Calcd. For C18H21N3O4: C, 62.96; H, 6.16; N, 12.24. Found: C, 62.92; H, 6.17; N, 12.15. The reaction mixture was heated to reflux overnight The solvent was evaporated in vacuo the residue dissolved in ethyl acetate (100 ml) The ethyl acetate mixture was washed with water (2×100 ml), saturated aqueous sodium bicarbonate (2×100 ml), brine (1×100 ml) dried (MgSO4) The solvent was evaporated in vacuo the solid residue was purified by chromatography (25% ethyl acetate/hexane)

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

Procedure: To a stirred solution of 3-(2-methoxy-ethylamino)-phthalic acid (8.38 mmol) in pyridine (40 ml) was added 3-amino-piperidine-2,6-dione hydrochloride (1.39 g, 8.42 mmol). The reaction mixture was heated to reflux for 5 hours. The solvent was evaporated in vacuo and the residue dissolved in methylene chloride (125 ml). The methylene chloride mixture was treated with Norit (2 g), washed with water (2×100 ml), 0.1N HCl (1×100 ml), brine (1×100 ml), and dried (MgSO4). The solvent was evaporated in vacuo and the residue (oil) crystallized from a minimal amount of ethanol to give a yellow solid that was purified by preparative HPLC to give 1.71 g (64%) of product as a yellow solid: mp 1.82-1,84° C.; 1H NMR (DMSO-d6) d 11.12 (s, 1H), 7.58 (t, J=7.7 Hz, 1H), 7.12 (d, J=8.5 Hz, 1H), 7.04 (d, J=6.9 Hz, 1H), 6.59 (bs, 1H), 5.07 (dd, J=4.7 and 12.1 Hz, 1H), 3.54-3.30 (m, 7H), 2.95-2.85 (m, 1H), 2.64-2.52 (m, 2H), 2.07-2.02 (m, 1H); 13C NMR (DMSO-d6) d 172.79, 170.06, 168.98, 167.27, 146.38, 136.21, 132.07, 117.33, 110.67, 109.24, 70.39, 58.12, 48.58, 41.50, 30.99, 22.15; Anal. Calcd. For C16H17N3O5: C, 58.00; H15.17; N, 12.68. Found: C, 58.06; H, 5.12; N, 12.76. The reaction mixture was heated to reflux for 5 hours The solvent was evaporated in vacuo the residue dissolved in methylene chloride (125 ml) The methylene chloride mixture was treated with Norit (2 g) washed with water (2×100 ml), 0.1N HCl (1×100 ml), brine (1×100 ml) dried (MgSO4) The solvent was evaporated in vacuo the residue (oil) crystallized from a minimal amount of ethanol to give a yellow solid that was purified by preparative HPLC

Conditions: temp:120.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,8-diazabicyclo[5,4,0]undec-7-ene (0.88 g, 6 mmol) was added to a stirred suspension of methyl-3-[(benzyloxycarbonylamino)methyl]-2-(methoxycarbonyl)benzoate (2.07 g, 6 mmol) and aminoglutarimide hydrochloride (0.95 g, 6 mmol) in DMF (15 ml). The mixture was heated to 120° C. for 24 hours. The mixture was cooled to room temperature and poured into water (150 ml). The mixture was extracted with ethyl acetate (3×30 ml) and the combined ethyl acetate extracts were washed with water (2×30 ml), brine (30 ml) and dried. Solvent was removed in vacuo and the residue was purified by chromatography (dichloromethane/ethyl acetate 8 to 2) to give 0.58 g (24%) of the product as a white solid: mp 166-168° C.; 1H NMR (DMSO-d6) δ 11.15 (s, 1H), 7.99-7.71 (m, 4H), 7.37 (m, 5H), 5.19-5.12 (dd, J=5.1 and 17.4 Hz, 1H), 5.07 (s, 2H), 4.70 (d, J=5.7 Hz, 2H), 2.97-2.83 (m, 1H), 2.64-2.51 (m, 2H), 2.08-2.04 (m, 1H); 13C NMR (DMSO-d6) δ 172.85, 169.89, 167.51, 167.01, 156.55, 139.46, 137.02, 134.87, 132.89, 131.57, 128.44, 127.92, 127.83, 127.06, 121.99, 65.69, 48.89, 30.97, 22.02; Anal. Calcd. For C22H19N3O6: C, 62.70; H, 4.54; N, 9.97. Found: C, 62.53; H, 4.57; N, 9.89. The mixture was cooled to room temperature The mixture was extracted with ethyl acetate (3×30 ml) the combined ethyl acetate extracts were washed with water (2×30 ml), brine (30 ml) dried Solvent was removed in vacuo the residue was purified by chromatography (dichloromethane/ethyl acetate 8 to 2)

Conditions: temp:120.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,8-Diazabicyclo[5,4,0]undec-7-ene (0.8 g, 5 mmol) was added to a stirred suspension of methyl-3-[(ethoxycarbonylamino)methyl]-2-(methoxycarbonyl)benzoate (1.54 g, 5 mmol) and aminoglutarimide hydrochloride (0.86 g, 5 mmol) in DMF (15 ml). The mixture was heated to 120° C. for 24 hours. The mixture was cooled to room temperature and poured into water (150 ml). The mixture was extracted with ethyl acetate (3×30 ml) and the ethyl acetate solution was washed with water (30 ml), brine (30 ml) and dried. Solvent was removed and the residue was purified by flash chromatography (dichloromethane/ethyl acetate 7 to 3) to give 0.84 g (45%) of the product as a white solid: mp 187-189° C.; 1H NMR (DMSO-d6) δ 11.03 (s, 1H), 7.76-7.58 (m, 4H), 5.06-4.99 (dd, J=5.4 and 12.6 Hz, 1H), 4.52 (d, J=5.9 Hz, 2H), 3.91 (q, J=7.0 Hz, 2H), 2.79-2.70 (m, 1H), 2.51-2.38 (m, 2H), 1.96-1.86 (m, 1H), 1.06 (t, J=7.0 Hz, 3H); 13C NMR (DMSO-d6) δ 172.89, 169.93, 167.55, 167.05, 156.72, 139.69, 134.91, 132.90, 131.58, 127.04, 121.97, 60.15, 48.90, 39.34, 30.98, 22.04, 14.69; Anal. Calcd. For C17H11N3O6: C, 56.82; H, 4.77; N, 11.69. Found: C, 56.94; H, 4.81; N, 11.37. The mixture was cooled to room temperature The mixture was extracted with ethyl acetate (3×30 ml) the ethyl acetate solution was washed with water (30 ml), brine (30 ml) dried Solvent was removed the residue was purified by flash chromatography (dichloromethane/ethyl acetate 7 to 3)