tert-butyl 2,5-dihydropyrrole-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:; See reaction.notes.procedure_details.

Procedure: 2.96 g (0.012 mole) of 70% aqueous m-chloroperbenzoic acid were added to a solution of 1.69 g (0.01 mole) of 1-t-butoxycarbonyl-3-pyrroline [prepared as described in Step (a) above] in 10 ml of chloroform, whilst ice-cooling, and the mixture was stirred with ice-cooling for 8 hours and then with water-cooling for 15 hours. At the end of this time, the reaction mixture was extracted with toluene and the extract was washed, in turn, with an aqueous solution of sodium bicarbonate, a 0.1N aqueous solution of sodium thiosulfate and water. It was then dried over anhydrous sodium sulfate, and the solvent was removed by evaporation under reduced pressure. The residue was subjected to silica gel column chromatography eluted with a 1:5 by volume mixture of ethyl acetate and toluene, to afford 1.09 g of 1-t-butoxycarbonyl-3,4-epoxypyrrolidine as a colorless oily substance. cooling cooling for 8 hours At the end of this time, the reaction mixture was extracted with toluene the extract was washed, in turn, with an aqueous solution of sodium bicarbonate It was then dried over anhydrous sodium sulfate the solvent was removed by evaporation under reduced pressure eluted with a 1:5 by volume mixture of ethyl acetate and toluene

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: Stir a mixture of 2,5-dihydropyrrole-1-carboxylic acid tert-butyl ester (2 g, 11.8 mmol), 3-chloroperoxybenzoic acid (77%, 3.1 g, 14.2 mmol) and 3-tert-butyl-4-hydroxy-5-methylsulfide (254 mg, 0.7 mmol) in 1,2-dichloroethane (50 mL) at 85° C. for 4 h under nitrogen. Add extra 3-chloroperoxybenzoic acid (77%, 1.16 g, 4.7 mmol) and stir at 85° C. for 5 h. Allow to cool to room temperature and add dichloromethane (120 mL), wash with 5% aqueous sodium bisulfate, then with saturated aqueous sodium hydrogen carbonate and finally with saturated aqueous sodium chloride, dry (magnesium sulfate), concentrate and chromatograph on silica gel, eluting with 0:100 to 40:60 ethyl acetate:cyclohexane to give 6-oxa-3-azabicyclo[3.1.0]hexane-3-carboxylic acid tert-butyl ester (1.55 g, 71%). 1H NMR (400 MHz, CDCl3) δ 3.82 (1H, d, J=13.20 Hz), 3.74 (1H, d, J=12.72 Hz), 3.67 (2H, d, J=3.42 Hz), 3.31 (2H, dd, J=13.45, 5.14 Hz), 1.44 (9H, s). stir at 85° C. for 5 h wash with 5% aqueous sodium bisulfate with saturated aqueous sodium hydrogen carbonate and finally with saturated aqueous sodium chloride, dry (magnesium sulfate) concentrate chromatograph on silica gel, eluting with 0:100 to 40:60 ethyl acetate

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

Procedure: Stir a mixture of 2,5-dihydropyrrole-1-carboxylic acid tert-butyl ester (2 g, 11.8 mmol), 3-chloroperoxybenzoic acid (77%, 3.1 g, 14.2 mmol) and 3-tert-butyl-4-hydroxy-5-methylsulfide (254 mg, 0.7 mmol) in 1,2-dichloroethane (50 mL) at 85° C. for 4 h under nitrogen. Add extra 3-chloroperoxybenzoic acid (77%, 1.16 g, 4.7 mmol) and stir at 85° C. for 5 h. Allow to cool to room temperature and add dichloromethane (120 mL), wash with 5% aqueous sodium bisulfate, then with saturated aqueous sodium hydrogen carbonate and finally with saturated aqueous sodium chloride, dry (magnesium sulfate), concentrate and chromatograph on silica gel, eluting with 0:100 to 40:60 ethyl acetate:cyclohexane to give 6-oxa-3-azabicyclo[3.1.0]hexane-3-carboxylic acid tert-butyl ester (1.55 g, 71%). 1H NMR (400 MHz, CDCl3) δ 3.82 (1H, d, J=13.20 Hz), 3.74 (1H, d, J=12.72 Hz), 3.67 (2H, d, J=3.42 Hz), 3.31 (2H, dd, J=13.45, 5.14 Hz), 1.44 (9H, s). stir at 85° C. for 5 h wash with 5% aqueous sodium bisulfate with saturated aqueous sodium hydrogen carbonate and finally with saturated aqueous sodium chloride, dry (magnesium sulfate) concentrate chromatograph on silica gel, eluting with 0:100 to 40:60 ethyl acetate

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

Procedure: 2,5-Dihydro-pyrrole-1-carboxylic acid tert-butyl ester (46 g, 65% purity) was dissolved in CH2Cl2 (500 mL). The solution was cooled to 0° C. mCPBA (122 g, 2 eq, 77% purity) was slowly added to the solution at 0° C. The reaction mixture was stirred at 0° C. to RT for overnight. The mixture was concentrated to 200 ml, and filtered. The organic phase was washed with 1 N NaOH solution (4×100 mL), dried over Na2SO4. The resulting oil was purified by column chromatography (hexane:ethyl acetate 3:1) to give 28 g of desired product as a colorless oil (87% yield). 1H-NMR (300 MHz, CDCl3): δ 1.41 (s, 9H), 3.26 (dd, 2H), 3.25-3.80 (m, 4H) was slowly added to the solution at 0° C The mixture was concentrated to 200 ml filtered The organic phase was washed with 1 N NaOH solution (4×100 mL) dried over Na2SO4 The resulting oil was purified by column chromatography (hexane:ethyl acetate 3:1)

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

Procedure: 2,5-Dihydro-pyrrole-1-carboxylic acid tert-butyl ester (46 g, 65% purity) was dissolved in CH2Cl2 (500 mL). The solution was cooled to 0° C. mCPBA (122 g, 2 eq, 77% purity) was slowly added to the solution at 0° C. The reaction mixture was stirred at 0° C. to RT for overnight. The mixture was concentrated to 200 ml, and filtered. The organic phase was washed with 1 N NaOH solution (4×100 mL), dried over Na2SO4. The resulting oil was purified by column chromatography (hexane:ethyl acetate 3:1) to give 28 g of desired product as a colorless oil (87% yield). 1H-NMR (300 MHz, CDCl3): δ 1.41 (s, 9H), 3.26 (dd, 2H), 3.25-3.80 (m, 4H) was slowly added to the solution at 0° C The mixture was concentrated to 200 ml filtered The organic phase was washed with 1 N NaOH solution (4×100 mL) dried over Na2SO4 The resulting oil was purified by column chromatography (hexane:ethyl acetate 3:1)

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

Procedure: Synthesized according to General Procedure 2. To a stirred solution of tert-butyl-2,5-dihydro-1H-pyrrole-1-carboxylate (2.5 g, 14.8 mmol) in methanol (75 mL) under N2 at RT was added 4-chloro-3-methylbenzenediazonium tetrafluoroborate (5.3 g, 22.2 mmol), followed by the addition of palladium(II) acetate (336 mg, 1.50 mmol). The resulting solution was stirred at RT for 1 hour, diluted with ethyl acetate (375 mL) and partitioned with saturated aqueous NaHCO3 solution (150 mL). The organic layer was removed and washed with saturated aqueous NaHCO3 solution (150 mL), brine (150 mL), dried over MgSO4 and concentrated under reduced pressure. The residue was dried under vacuum to afford tert-butyl 4-(4-chloro-3-methylphenyl)-2-methoxypyrrolidine-1-carboxylate (4.25 g, 13.0 mmol, 88% yield) as a brown oil. The crude product was used without any further purification in the next reaction step. 1H-NMR (400 MHz, DMSO-d6) δ 7.35-7.26 (m, 2H), 7.16 (dd, J=1.9, 8.2 Hz, 1H), 5.20-5.05 (m, 1H), 3.70-3.63 (m, 1H), 3.54-3.45 (m, 1H), 3.28 (s, 3H), 3.21-3.10 (m, 1H), 2.30 (s, 3H), 2.10-1.98 (m, 2H) and 1.47 (s, 9H) ppm. Synthesized partitioned with saturated aqueous NaHCO3 solution (150 mL) The organic layer was removed washed with saturated aqueous NaHCO3 solution (150 mL), brine (150 mL) dried over MgSO4 concentrated under reduced pressure The residue was dried under vacuum