tert-butyl N-(2,6-dioxopiperidin-3-yl)carbamate

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

Procedure: Compound 203 (1.14 g, 5 mmol) was suspended in CH2Cl2 (100 mL). To the mixture was added CF3COOH (10 mL) and this then was stirred at room temperature for 4 h. The solvent was evaporated to give crude 204 (1.25 g): 1H NMR (DMSO-d6) δ 11.42 (s, 1H), 8.70 (br, 2H), 4.31 (dd, J=5.4 Hz, J=13 Hz), 2.88-2.72 (m, 2H), 2.25-2.09 (m, 2H). A mixture of crude 204 (1.25 g) and phthalic anhydride (0.89 g, 6 mmol) and Et3N (1.39 ml, 10 mmol) in THF (150 mL) was refluxed for two days. The reaction mixture was concentrated and the residue was crystallized from ethyl acetate to give thalidomide (201) (0.89 g, 69%) as white crystals; mp 276° C. (lit. 276-279° C.). A mixture of thalidomide 201 (258 mg, 1 mmol) and Lawesson's reagent (222 mg, 0.55 mmol) in toluene (50 ml) was stirred at reflux for 12 h; thereafter, solvent was removed under vacuum. The resulting residue was purified by column chromatography using CH2Cl2 as the eluent to afford compound 205 (200 mg, 73%) as a yellow solid: mp 225-226° C.; 1H NMR (DMSO-d6) δ 12.83 (s, 1H, NH), 8.00-7.92 (m, 4H, Ph), 5.32 (dd, J=5.6 Hz, J=12.9 Hz, 1H, H-3′), 3.28-3.25 (m, 2H, H-5′), 2.60-2.54 (m, 1H, H-4′), 2.17-2.10 (m, 1H, H-4′); 13C NMR (DMSO-d6) δ 208.7 (C-6′), 165.3 (C-2′), 165.2 (C-1 & C-3), 133.1 (C-5 & C-6), 129.3 (C-3a, C-7a), 121.7 (C-4 & C-7), 46.9 (C-3′), 38.9 (C-5′), 21.79 (C-4′); MS (CI/CH4) m/z 274 (M+); Anal. (C13H10N2O3S) C, H, N. The solvent was evaporated

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

Procedure: Compound 203 (1.14 g, 5 mmol) was suspended in CH2Cl2 (100 mL). To the mixture was added CF3COOH (10 mL) and this then was stirred at room temperature for 4 h. The solvent was evaporated to give crude 204 (1.25 g): 1H NMR (DMSO-d6) δ 11.42 (s, 1H), 8.70 (br, 2H), 4.31 (dd, J=5.4 Hz, J=13 Hz), 2.88-2.72 (m, 2H), 2.25-2.09 (m, 2H). A mixture of crude 204 (1.25 g) and phthalic anhydride (0.89 g, 6 mmol) and Et3N (1.39 ml, 10 mmol) in THF (150 mL) was refluxed for two days. The reaction mixture was concentrated and the residue was crystallized from ethyl acetate to give thalidomide (201) (0.89 g, 69%) as white crystals; mp 276° C. (lit. 276-279° C.). A mixture of thalidomide 201 (258 mg, 1 mmol) and Lawesson's reagent (222 mg, 0.55 mmol) in toluene (50 ml) was stirred at reflux for 12 h; thereafter, solvent was removed under vacuum. The resulting residue was purified by column chromatography using CH2Cl2 as the eluent to afford compound 205 (200 mg, 73%) as a yellow solid: mp 225-226° C.; 1H NMR (DMSO-d6) δ 12.83 (s, 1H, NH), 8.00-7.92 (m, 4H, Ph), 5.32 (dd, J=5.6 Hz, J=12.9 Hz, 1H, H-3′), 3.28-3.25 (m, 2H, H-5′), 2.60-2.54 (m, 1H, H-4′), 2.17-2.10 (m, 1H, H-4′); 13C NMR (DMSO-d6) δ 208.7 (C-6′), 165.3 (C-2′), 165.2 (C-1 & C-3), 133.1 (C-5 & C-6), 129.3 (C-3a, C-7a), 121.7 (C-4 & C-7), 46.9 (C-3′), 38.9 (C-5′), 21.79 (C-4′); MS (CI/CH4) m/z 274 (M+); Anal. (C13H10N2O3S) C, H, N. The solvent was evaporated

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

Procedure: A mixture of N-(tert-butoxycarbonyl)-L-glutamine (4.92 g, 20 mmol) and carbonyl diimidazole (3.24 g, 20 mmol) in THF (100 mL) was refluxed for 16 h. Thereafter, solvent was removed and the crude product was recrystallized from hot EtOAc to give compound 203 (2.04 g, 45%) as white crystals: mp 214-215° C.; 1H NMR (DMSO-d6) δ 4.22 (dd, J=6.2 Hz, J=11.0 Hz, 1H), 2.77-2.65 (m, 1H), 2.45 (m, 1H), 1.96-1.87 (m, 2H), 1.40 (s, 9H); MS (CI/CH4) m/z 227 [M−1]+. was refluxed for 16 h Thereafter, solvent was removed the crude product was recrystallized from hot EtOAc

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

Procedure: 2,6-Dioxo-3-aminopiperidine trifluoroacetate (4) was prepared and isolated as follows. Compound 3 (59 mg) was suspended in CH2Cl2 (5 mL). CF3COOH (0.5 mL) was added. The reaction solution was stirred at room temperature for 4 h. The solvent was removed to give 4 (62 mg, 99%): 1H NMR (DMSO-d6) δ 11.42 (s, 1H), 8.70 (br, 2H), 4.31 (dd, J=5.4 Hz, J=13 Hz), 2.88-2.72 (m, 2H), 2.25-2.09 (m, 2H). 2,6-Dioxo-3-aminopiperidine trifluoroacetate (4) was prepared isolated The solvent was removed

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

Procedure: 2,6-Dioxo-3-(t-butoxycarbonylamino)piperidine (3) was prepared and isolated as follows. A solution of N-(t-butoxycarbonyl)-L-glutamine (4.92 g) and carbonyl diimidazole (1.70 g) in THF (100 mL) was refluxed for 9 h. The solvent was removed and the crude product was recrystallized from hot EtOAc to give compound 3 (2.04 g, 45%) as white crystals: mp 214-215° C.; 1H NMR (DMSO-d6) δ 4.22 (dd, J=6.2 Hz, J=11.0 Hz, 1H), 2.77-2.65 (m, 1H), 2.45 (m, 1H), 1.96-1.87 (m, 2H), 1.40 (s, 9H); MS (CI/CH4) 227 [M−1]+. 2,6-Dioxo-3-(t-butoxycarbonylamino)piperidine (3) was prepared isolated The solvent was removed the crude product was recrystallized from hot EtOAc

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

Procedure: Compound 203 (1.14 g, 5 mmol) was suspended in CH2Cl2 (100 mL). To the mixture was added CF3COOH (10 mL) and this then was stirred at room temperature for 4 h. The solvent was evaporated to give crude 204 (1.25 g): 1H NMR (DMSO-d6) δ 11.42 (s, 1H), 8.70 (br, 2H), 4.31 (dd, J=5.4 Hz, J=13 Hz), 2.88-2.72 (m, 2H), 2.25-2.09 (m, 2H). A mixture of crude 204 (1.25 g) and phthalic anhydride (0.89 g, 6 mmol) and Et3N (1.39 ml, 10 mmol) in THF (150 mL) was refluxed for two days. The reaction mixture was concentrated and the residue was crystallized from ethyl acetate to give thalidomide (201) (0.89 g, 69%) as white crystals; mp 276° C. (lit. 276-279° C.). A mixture of thalidomide 201 (258 mg, 1 mmol) and Lawesson's reagent (222 mg, 0.55 mmol) in toluene (50 ml) was stirred at reflux for 12 h; thereafter, solvent was removed under vacuum. The resulting residue was purified by column chromatography using CH2Cl2 as the eluent to afford compound 205 (200 mg, 73%) as a yellow solid: mp 225-226° C.; 1H NMR (DMSO-d6) δ 12.83 (s, 1H, NH), 8.00-7.92 (m, 4H, Ph), 5.32 (dd, J=5.6 Hz, J=12.9 Hz, 1H, H-3′), 3.28-3.25 (m, 2H, H-5′), 2.60-2.54 (m, 1H, H-4′), 2.17-2.10 (m, 1H, H-4′); 13C NMR (DMSO-d6) δ 208.7(C-6′), 165.3(C-2′), 165.2(C-1 & C-3), 133.1(C-5 & C-6), 129.3 (C-3a, C-7a), 121.7 (C -4 & C-7), 46.9 (C-3′), 38.9 (C-5′), 21.79 (C-4′); MS (CI/CH4) m/z 274 (M+); Anal. (C13H10N2O3S) C, H, N. The solvent was evaporated

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

Procedure: A mixture of N -(tert-butoxycarbonyl)-L-glutamine (4.92 g, 20 mmol) and carbonyl diimidazole (3.24 g, 20 mmol) in THF (100 mL) was refluxed for 16 h. Thereafter, solvent was removed and the crude product was recrystallized from hot EtOAc to give compound 203 (2.04 g, 45%) as white crystals: mp 214-215° C.; 1H NMR (DMSO-d6) δ 4.22 (dd, J=6.2 Hz, J=11.0 Hz, 1H), 2.77-2.65 (m, 1H), 2.45 (m, 1H), 1.96-1.87 (m, 2H), 1.40 (s, 9H); MS (CI/CH4) m/z 227 [M−1]+. was refluxed for 16 h Thereafter, solvent was removed the crude product was recrystallized from hot EtOAc

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

Procedure: A mixture of N -(tert-butoxycarbonyl)-L-glutamine (4.92 g, 20 mmol) and carbonyl diimidazole (3.24 g, 20 mmol) in THF (100 mL) was refluxed for 16 h. Thereafter, solvent was removed and the crude product was recrystallized from hot EtOAc to give compound 203 (2.04 g, 45%) as white crystals: mp 214-215° C.; 1H NMR (DMSO-d6) δ 4.22 (dd, J=6.2 Hz, J=11.0 Hz, 1H), 2.77-2.65 (m, 1H), 2.45 (m, 1H), 1.96-1.87 (m, 2H), 1.40 (s, 9H); MS (CI/CH4) m/z 227 [M−1]+. was refluxed for 16 h Thereafter, solvent was removed the crude product was recrystallized from hot EtOAc

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

Procedure: 2,6-Dioxo-3-aminopiperidine trifluoroacetate (4) was prepared and isolated as follows. Compound 3 (59 mg) was suspended in CH2Cl2 (5 mL). CF3COOH (0.5 mL) was added. The reaction solution was stirred at room temperature for 4 h. The solvent was removed to give 4 (62 mg, 99%): 1H NMR (DMSO-d6) δ 11.42 (s, 1H), 8.70 (br, 2H), 4.31 (dd, J=5.4 Hz, J=13 Hz), 2.88-2.72 (m, 2H), 2.25-2.09 (m, 2H). 2,6-Dioxo-3-aminopiperidine trifluoroacetate (4) was prepared isolated The solvent was removed

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

Procedure: 2,6-Dioxo-3-(t-butoxycarbonylamino)piperidine (3) was prepared and isolated as follows. A solution of N-(t-butoxycarbonyl)-L-glutamine (4.92 g) and carbonyl diimidazole (1.70 g) in THF (100 mL) was refluxed for 9 h. The solvent was removed and the crude product was recrystallized from hot EtOAc to give compound 3 (2.04 g, 45%) as white crystals: mp 214-215° C.; 1H NMR (DMSO-d6) δ 4.22 (dd, J=6.2 Hz, J=11.0 Hz, 1H), 2.77-2.65 (m, 1H), 2.45 (m, 1 H), 1.96-1.87 (m, 2H), 1.40 (s, 9H); MS (CI/CH4) 227 [M−1]+. 2,6-Dioxo-3-(t-butoxycarbonylamino)piperidine (3) was prepared isolated The solvent was removed the crude product was recrystallized from hot EtOAc

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

Procedure: 2,6-Dioxo-3-(t-butoxycarbonylamino)piperidine (3) was prepared and isolated as follows. A solution of N-(t-butoxycarbonyl)-L-glutamine (4.92 g) and carbonyl diimidazole (1.70 g) in THF (100 mL) was refluxed for 9 h. The solvent was removed and the crude product was recrystallized from hot EtOAc to give compound 3 (2.04 g, 45%) as white crystals: mp 214-215° C.; 1H NMR (DMSO-d6) δ 4.22 (dd, J=6.2 Hz, J=11.0 Hz, 1H), 2.77-2.65 (m, 1H), 2.45 (m, 1 H), 1.96-1.87 (m, 2H), 1.40 (s, 9H); MS (CI/CH4) 227 [M−1]+. 2,6-Dioxo-3-(t-butoxycarbonylamino)piperidine (3) was prepared isolated The solvent was removed the crude product was recrystallized from hot EtOAc

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

Procedure: Compound 203 (1.14 g, 5 mmol) was suspended in CH2Cl2 (100 mL). To the mixture was added CF3COOH (10 mL) and this then was stirred at room for 4 h. The solvent was evaporated to give crude 204 (1.25 g): 1H NMR (DMSO-d6) δ 11.42 (s, 1H), 8.70 (br, 2H), 4.31 (dd, J=5.4 Hz, J=13 Hz), 2.88-2.72 (m, 2H), 2.25-2.09 (m, 2H). A mixture of crude 204 (1.25 g) and phthalic anhydride (0.89 g, 6 mmol) and Et3N (1.39 ml, 10 mmol) in THF (150 mL) was refluxed for two days. The reaction mixture was concentrated and the residue was crystallized from ethyl acetate to give thalidomide (201) (0.89 g, 69%) as white crystals; mp 276° C. (lit.276-279° C.). A mixture of thalidomide 201 (258 mg, 1 mmol) and Lawesson's reagent (222 mg, 0.55 mmol) in toluene (50 ml) was stirred at reflux for 12 h; thereafter, solvent was removed under vacuum. The resulting residue was purified by column chromatography using CH2Cl2 as the eluent to afford compound 205 (200 mg, 73%) as a yellow solid: mp 225-226° C.; 1H NMR (DMSO-d6) δ 12.83 (s, 1H, NH), 8.00-7.92 (m, 4H, Ph), 5.32 (dd, J=5.6 Hz, J=12.9 Hz, 1H, H-3′), 3.28-3.25 (m, 2H, H-5′), 2.60-2.54 (m, 1H, H-4′), 2.17-2.10 (m, 1H, H-4′); 13C NMR (DMSO-d6) δ 208.7 (C-6′), 165.3 (C-2′), 165.2 (C-1 & C-3), 133.1 (C-5 & C-6), 129.3 (C-3a, C-7a), 121.7 (C-4 & C-7), 46.9 (C-3′), 38.9 (C-5′), 21.79 (C-4′); MS (CI/CH4) m/z 274 (M+); Anal. (C13H10N2O3S) C, H, N. The solvent was evaporated