tert-butyl 4-amino-3,3-difluoropyrrolidine-1-carboxylate

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

Procedure: To a reaction flask was added tert-butyl 4-amino-3,3-difluoropyrrolidine-1-carboxylate (1.36 g, 6.12 mmol), 3-(methylsulfonyl)propanoic acid (1.02 g, 6.73 mmol, 1.1 mol eq), DCM (31 mL, 0.4 M), NMM (1.35 mL, 12.2 mmol, 2 mol eq), HOBt (1.31 g, 9.2 mmol, 1.5 mol eq) and EDC-HCl (1.85 g, 9.2 mmol, 1.5 mol eq). The resulting suspension was stirred at ambient temperature under a nitrogen atmosphere for 2 hr. The reaction was diluted with DCM (80 mL), washed with aqueous NaHCO3 (2×30 mL) and the organic layer was dried over Na2SO4 and evaporated to give a residue that was purified via silica flash chromatography eluting with gradients from 100% heptane to 100% ethyl acetate to give the title product as a white foamy solid (1.65 g, 76% yield, >95% purity). 1H NMR (400 MHz, chloroform-d) δ ppm 6.45 (br. s., 1 H) 4.68-4.89 (m, 1 H) 3.94 (dd, J=10.70, 8.62 Hz, 1 H) 3.62-3.86 (m, 2 H) 3.43 (t, J=7.15 Hz, 2 H) 3.18 (br. s., 1 H) 2.97 (s, 3 H) 2.84 (td, J=7.15, 1.96 Hz, 2 H) 1.47 (s, 9 H). 19F NMR (376 MHz, chloroform-d) δ ppm −112.79-−110.52 (m, 1 F) −114.51-−113.30 (m, 1 F). m/z (APCI+) for C13H22F2N2O5S 257.1 (M+H)+. washed with aqueous NaHCO3 (2×30 mL) the organic layer was dried over Na2SO4 evaporated to give a residue that was purified via silica flash chromatography eluting with gradients from 100% heptane to 100% ethyl acetate

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

Procedure: To a reaction flask was added tert-butyl 4-amino-3,3-difluoropyrrolidine-1-carboxylate (1.36 g, 6.12 mmol), 3-(methylsulfonyl)propanoic acid (1.02 g, 6.73 mmol, 1.1 mol eq), DCM (31 mL, 0.4 M), NMM (1.35 mL, 12.2 mmol, 2 mol eq), HOBt (1.31 g, 9.2 mmol, 1.5 mol eq) and EDC-HCl (1.85 g, 9.2 mmol, 1.5 mol eq). The resulting suspension was stirred at ambient temperature under a nitrogen atmosphere for 2 hr. The reaction was diluted with DCM (80 mL), washed with aqueous NaHCO3 (2×30 mL) and the organic layer was dried over Na2SO4 and evaporated to give a residue that was purified via silica flash chromatography eluting with gradients from 100% heptane to 100% ethyl acetate to give the title product as a white foamy solid (1.65 g, 76% yield, >95% purity). 1H NMR (400 MHz, chloroform-d) δ ppm 6.45 (br. s., 1 H) 4.68-4.89 (m, 1 H) 3.94 (dd, J=10.70, 8.62 Hz, 1 H) 3.62-3.86 (m, 2 H) 3.43 (t, J=7.15 Hz, 2 H) 3.18 (br. s., 1 H) 2.97 (s, 3 H) 2.84 (td, J=7.15, 1.96 Hz, 2 H) 1.47 (s, 9 H). 19F NMR (376 MHz, chloroform-d) δ ppm −112.79-−110.52 (m, 1 F) −114.51-−113.30 (m, 1 F). m/z (APCI+) for C13H22F2N2O5S 257.1 (M+H)+. washed with aqueous NaHCO3 (2×30 mL) the organic layer was dried over Na2SO4 evaporated to give a residue that was purified via silica flash chromatography eluting with gradients from 100% heptane to 100% ethyl acetate

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

Procedure: A solution of tert-butyl 4-azido-3,3-difluoropyrrolidine-1-carboxylate (3.01 g, 12.1 mmol) in ethanol (300 mL) was degassed with nitrogen and 20% Pd/C (300 mg) was added. The resulting mixture was stirred under hydrogen atmosphere (balloon) for 16 hr. The catalyst was removed by filtration. The filtrate was evaporated to give the title product as an oil (2.63 g, 98% yield, >85% purity). 1H NMR (400 MHz, chloroform-d) δ ppm 3.73-3.87 (m, 2 H) 3.69 (d, J=10.64 Hz, 1 H) 3.50-3.62 (m, 1 H) 3.13 (d, J=6.85 Hz, 1 H) 1.45-1.48 (m, 9 H). 19F NMR (376 MHz, chloroform-d) δ ppm −115.05-−110.78 (m, 1F) −120.95-−117.90 (m, 1 F). m/z (APCI+) for C9H16F2N2O2 123 (M+H)+. was added The catalyst was removed by filtration The filtrate was evaporated

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

Procedure: To a reaction flask was added tert-butyl 4-amino-3,3-difluoropyrrolidine-1-carboxylate (1.36 g, 6.12 mmol), 3-(methylsulfonyl)propanoic acid (1.02 g, 6.73 mmol, 1.1 mol eq), DCM (31 mL, 0.4 M), NMM (1.35 mL, 12.2 mmol, 2 mol eq), HOBt (1.31 g, 9.2 mmol, 1.5 mol eq) and EDC-HCl (1.85 g, 9.2 mmol, 1.5 mol eq). The resulting suspension was stirred at ambient temperature under a nitrogen atmosphere for 2 hr. The reaction was diluted with DCM (80 mL), washed with aqueous NaHCO3 (2×30 mL) and the organic layer was dried over Na2SO4 and evaporated to give a residue that was purified via silica flash chromatography eluting with gradients from 100% heptane to 100% ethyl acetate to give the title product as a white foamy solid (1.65 g, 76% yield, >95% purity). 1H NMR (400 MHz, chloroform-d) δ ppm 6.45 (br. s., 1 H) 4.68-4.89 (m, 1 H) 3.94 (dd, J=10.70, 8.62 Hz, 1 H) 3.62-3.86 (m, 2 H) 3.43 (t, J=7.15 Hz, 2 H) 3.18 (br. s., 1 H) 2.97 (s, 3 H) 2.84 (td, J=7.15, 1.96 Hz, 2 H) 1.47 (s, 9 H). 19F NMR (376 MHz, chloroform-d) δ ppm −112.79-−110.52 (m, 1 F) −114.51-−113.30 (m, 1 F). m/z (APCI+) for C13H22F2N2O5S 257.1 (M+H)+. washed with aqueous NaHCO3 (2×30 mL) the organic layer was dried over Na2SO4 evaporated to give a residue that was purified via silica flash chromatography eluting with gradients from 100% heptane to 100% ethyl acetate

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

Procedure: A solution of tert-butyl 4-azido-3,3-difluoropyrrolidine-1-carboxylate (3.01 g, 12.1 mmol) in ethanol (300 mL) was degassed with nitrogen and 20% Pd/C (300 mg) was added. The resulting mixture was stirred under hydrogen atmosphere (balloon) for 16 hr. The catalyst was removed by filtration. The filtrate was evaporated to give the title product as an oil (2.63 g, 98% yield, >85% purity). 1H NMR (400 MHz, chloroform-d) δ ppm 3.73-3.87 (m, 2 H) 3.69 (d, J=10.64 Hz, 1 H) 3.50-3.62 (m, 1 H) 3.13 (d, J=6.85 Hz, 1 H) 1.45-1.48 (m, 9 H). 19F NMR (376 MHz, chloroform-d) δ ppm −115.05-−110.78 (m, 1F) −120.95-−117.90 (m, 1 F). m/z (APCI+) for C9H16F2N2O2 123 (M+H)+. was added The catalyst was removed by filtration The filtrate was evaporated