tert-butyl pyrazolidine-1-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: The title compound was synthesized in analogy to Example 1 using 5-(4-chlorophenyl)-6-(2,2,2-trifluoroethoxy)-3-pyridinecarboxylic acid (CAN 1018782-82-5) and 1-pyrazolidinecarboxylic acid 1,1-dimethylethyl ester (CAN 57699-91-9) as starting materials; MS (EI) 486.2 (M+H)+.

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

Procedure: The title compound was synthesized in analogy to Example 1 using 5-(4-chlorophenyl)-6-(2,2,2-trifluoroethoxy)-3-pyridinecarboxylic acid (CAN 1018782-82-5) and 1-pyrazolidinecarboxylic acid 1,1-dimethylethyl ester (CAN 57699-91-9) as starting materials; MS (EI) 486.2 (M+H)+.

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

Procedure: Tert-butyl pyrazolidine-1-carboxylate (39) (1.39 g, 8.08 mmoles) was acylated with Fmoc succinimide (3.27 g, 9.69 mmoles, 1.2 eq.) in dry dichloromethane (20 mL). The reactive mixture was left stirring overnight. The volatiles were removed using a rotary evaporator and the residue was dissolved in EtOAc. The organic layer was extracted three times, respectively, with 5% citric acid, 5% NaHCO3 and brine, dried over Na2SO4, filtered and concentrated to a white foam which was purified by column chromatography using 7:3 EtOAc:Hexane as eluant. Evaporation of the collected fractions afforded 1-(9H-fluoren-9-yl)methyl 2-tert-butyl pyrazolidine-1,2-dicarboxylate as a white solid in a 94% yield. Pyrazolidine-1,2-dicarboxylate (1.34 g, 3.4 mmoles) was treated with 25 mL of a 1:1 TFA:DCM solution and stirred for one hour. Removal of the volatiles by rotary evaporation gave a residue that was dissolved in 1N HCl, stirred for 1 hour and freeze-dryed to yield hydrochloride (9H-fluoren-9-yl)methyl-1-carboxylate: mp (143.2-148.1° C.), 1H NMR (DMSO) δ 7.89 (d, J=7.32 Hz, 2H), 7.72 (d, J=7.33 Hz, 2H), 7.43 (ddd, J=7.36 Hz, 0.57 Hz, 2H), 7.33 (ddd, J=7.42 Hz, 1.14 Hz, 2H), 4.44 (d, J=6.90 Hz, 2H), 4.33 (t, J=6.56 Hz, 1H), 3.58 (t, J=6.96 Hz, 2H), 3.43 (t, J=6.96 Hz, 2H), 2.20 (m, 2H). 13C (DMSO) δ 154.57, 144.64, 142.11, 129.26, 126.54, 121.67, 69.89, 47.50, 25.50. The reactive mixture was left The volatiles were removed a rotary evaporator the residue was dissolved in EtOAc The organic layer was extracted three times respectively, with 5% citric acid, 5% NaHCO3 and brine, dried over Na2SO4 filtered concentrated to a white foam which was purified by column chromatography Evaporation of the collected fractions

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

Procedure: Tert-butyl pyrazolidine-1-carboxylate (39) (1.39 g, 8.08 mmoles) was acylated with Fmoc succinimide (3.27 g, 9.69 mmoles, 1.2 eq.) in dry dichloromethane (20 mL). The reactive mixture was left stirring overnight. The volatiles were removed using a rotary evaporator and the residue was dissolved in EtOAc. The organic layer was extracted three times, respectively, with 5% citric acid, 5% NaHCO3 and brine, dried over Na2SO4, filtered and concentrated to a white foam which was purified by column chromatography using 7:3 EtOAc:Hexane as eluant. Evaporation of the collected fractions afforded 1-(9H-fluoren-9-yl)methyl 2-tert-butyl pyrazolidine-1,2-dicarboxylate as a white solid in a 94% yield. Pyrazolidine-1,2-dicarboxylate (1.34 g, 3.4 mmoles) was treated with 25 mL of a 1:1 TFA:DCM solution and stirred for one hour. Removal of the volatiles by rotary evaporation gave a residue that was dissolved in 1N HCl, stirred for 1 hour and freeze-dryed to yield hydrochloride (9H-fluoren-9-yl)methyl-1-carboxylate: mp (143.2-148.1° C.), 1H NMR (DMSO) δ 7.89 (d, J=7.32 Hz, 2H), 7.72 (d, J=7.33 Hz, 2H), 7.43 (ddd, J=7.36 Hz, 0.57 Hz, 2H), 7.33 (ddd, J=7.42 Hz, 1.14 Hz, 2H), 4.44 (d, J=6.90 Hz, 2H), 4.33 (t, J=6.56 Hz, 1H), 3.58 (t, J=6.96 Hz, 2H), 3.43 (t, J=6.96 Hz, 2H), 2.20 (m, 2H). 13C (DMSO) δ 154.57, 144.64, 142.11, 129.26, 126.54, 121.67, 69.89, 47.50, 25.50. The reactive mixture was left The volatiles were removed a rotary evaporator the residue was dissolved in EtOAc The organic layer was extracted three times respectively, with 5% citric acid, 5% NaHCO3 and brine, dried over Na2SO4 filtered concentrated to a white foam which was purified by column chromatography Evaporation of the collected fractions

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

Procedure: The title compound was synthesized in analogy to Example 1 using 5-(4-chlorophenyl)-6-(2,2,2-trifluoroethoxy)-3-pyridinecarboxylic acid (CAN 1018782-82-5) and 1-pyrazolidinecarboxylic acid 1,1-dimethylethyl ester (CAN 57699-91-9) as starting materials; MS (EI) 486.2 (M+H)+.

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

Procedure: 340 mg (1.5 mmol) of 4-(4-amino-2-chlorophenyl)morpholin-3-one are dissolved in 10 ml of dichloromethane (DCM), 302 mg (1.5 mmol) of 4-nitrophenyl chloroformate and 121 μl (1.5 mmol) of pyridine are subsequently added successively, and the mixture is stirred at RT for 1 h. 300.0 mg (0.7 mmol) of tert-butyl pyrazolidine-1-carboxylate and 0.765 mg (4.5 mmol) of N-ethyldiisopropylamine are added to this reaction mixture. After stirring at RT for 20 h, the mixture is subjected to conventional work-up, giving 420 mg (57.3%) of step 1; MS (FAB) m/e=425/427 (M+H)+. After stirring at RT for 20 h giving 420 mg (57.3%) of step 1