2-(oxolan-2-yl)aniline

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

Procedure: To a stirring solution of 2-tetrahydrofuran-2-yl-aniline (4) (53.45 g, 327.5 mmol) in methyl tert-butyl ether (MTBE, 641.4 mL) and acetonitrile (213.8 mL) cooled to 2° C. was added N-bromosuccinimide (58.88 g, 99%, 327.5 mmol, Aldrich B81255) in 4 portions maintaining internal temperature below about 8° C. The reaction mixture was stirred while cooling with an ice-water bath for 30 minutes (NMR of a worked-up aliquot showed complete consumption of starting material). Added aqueous 1 N Na2S2O3 (330 mL), removed the cold bath and stirred for 20 minutes. The mixture was diluted with EtOAc and the layers were separated. The organic phase was washed with saturated aqueous NaHCO3 (2×), water, brine, dried over MgSO4, filtered through a short plug of silica, eluted with EtOAc, and concentrated under reduced pressure to give (5) as a very dark amber oil (82.25 g, 77-94% HPLC purity). Carried forward without further purification. LCMS (C18 column eluting with 10-90% CH3CN/water gradient over 5 minutes with formic acid modifier) M+1: 242.10 (2.89 min). 1H NMR (300 MHz, CDCl3) δ 7.22 (d, J=2.3 Hz, 1H), 7.16 (dd, J=8.4, 2.3 Hz, 1H), 6.54 (d, J=8.4 Hz, 1H), 4.79-4.73 (m, 1H), 4.15 (s, 2H), 4.10-4.01 (m, 1H), 3.93-3.85 (m, 1H), 2.26-2.13 (m, 1H), 2.12-1.97 (m, 3H) ppm. maintaining internal temperature below about 8° C while cooling with an ice-water bath for 30 minutes (NMR of complete consumption of starting material) Added aqueous 1 N Na2S2O3 (330 mL), removed the cold bath stirred for 20 minutes The mixture was diluted with EtOAc the layers were separated The organic phase was washed with saturated aqueous NaHCO3 (2×), water, brine dried over MgSO4 filtered through a short plug of silica eluted with EtOAc concentrated under reduced pressure

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

Procedure: To a stirring solution of 2-tetrahydrofuran-2-yl-aniline (4) (53.45 g, 327.5 mmol) in methyl tert-butyl ether (MTBE, 641.4 mL) and acetonitrile (213.8 mL) cooled to 2° C. was added N-bromosuccinimide (58.88 g, 99%, 327.5 mmol, Aldrich B81255) in 4 portions maintaining internal temperature below about 8° C. The reaction mixture was stirred while cooling with an ice-water bath for 30 minutes (NMR of a worked-up aliquot showed complete consumption of starting material). Added aqueous 1 N Na2S2O3 (330 mL), removed the cold bath and stirred for 20 minutes. The mixture was diluted with EtOAc and the layers were separated. The organic phase was washed with saturated aqueous NaHCO3 (2×), water, brine, dried over MgSO4, filtered through a short plug of silica, eluted with EtOAc, and concentrated under reduced pressure to give (5) as a very dark amber oil (82.25 g, 77-94% HPLC purity). Carried forward without further purification. LCMS (C18 column eluting with 10-90% CH3CN/water gradient over 5 minutes with formic acid modifier) M+1: 242.10 (2.89 min). 1H NMR (300 MHz, CDCl3) δ 7.22 (d, J=2.3 Hz, 1H), 7.16 (dd, J=8.4, 2.3 Hz, 1H), 6.54 (d, J=8.4 Hz, 1H), 4.79-4.73 (m, 1H), 4.15 (s, 2H), 4.10-4.01 (m, 1H), 3.93-3.85 (m, 1H), 2.26-2.13 (m, 1H), 2.12-1.97 (m, 3H) ppm. maintaining internal temperature below about 8° C while cooling with an ice-water bath for 30 minutes (NMR of complete consumption of starting material) Added aqueous 1 N Na2S2O3 (330 mL), removed the cold bath stirred for 20 minutes The mixture was diluted with EtOAc the layers were separated The organic phase was washed with saturated aqueous NaHCO3 (2×), water, brine dried over MgSO4 filtered through a short plug of silica eluted with EtOAc concentrated under reduced pressure

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

Procedure: Dissolved 33 g of compound (4) into MeOH (265 ml) which resulted in a concentration of approximately 125 mg/ml. The mixture was filtered through a 0.2 micron membrane filter then chromatographed on a ChiralPak® IC column (30 mm×150 mm, column temp 35° C., Chiral Technologies) at 100 bar using a Berger multigram supercritical fluid chromatographic system. Mobile phase was (90:10) CO2:CH3OH eluting at 350 ml/min with UV monitoring at 220 nanometers. Obtained 15.64 g of desired product (4a) as a green oil. Analytical SFC ([90:10] CO2:CH3OH, at 5 ml/min on a ChiralPak IC column (4.6×100 mm) held at 35° C. and run at 100 bar pressure with UV monitoring at 220 nm) showed 95.5% ee with 95% overall purity. resulted in a concentration of approximately 125 mg/ml The mixture was filtered through a 0.2 micron membrane filter then chromatographed on a ChiralPak® IC column (30 mm×150 mm, column temp 35° C., Chiral Technologies) at 100 bar

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

Procedure: Placed 5% palladium on carbon (16.3 g, 50% wet, 3.83 mmol, Aldrich 330116) in a Parr bottle under nitrogen, followed by MeOH (100 mL, JT-Baker 909333). Added the crude mixture of 2-(2-nitrophenyl)-2,5-dihydrofuran and 2-(2-nitrophenyl)-2,3-dihydrofuran (3a&3b)) (163 g) dissolved in MeOH (389 mL), followed by NEt3 (237.6 mL, 1.705 mol, Sigma-Aldrich 471283). Placed the vessel on a Parr shaker and saturated with H2. Added 30 psi H2 and shook until consumption complete (LCMS and NMR showed complete reaction). The reaction mixture was purged with nitrogen, filtered through Celite™ and rinsed with EtOAc. The filtrate was concentrated on a rotary evaporator giving a brown oil. Repeated the reaction three more times on the same scale and the batches were combined for purification. The crude product was vacuum distilled (ca. 15 ton) collecting the distillate at 108-129° C. to give (4) as a clear faint yellow oil (427.9 g, average yield was 84%; 98% GCMS purity). LCMS (C18 column eluting with 10-90% CH3CN/water gradient over 5 minutes with formic acid modifier) M+1: 163.95 (1.46 min). 1H NMR (300 MHz, CDCl3): δ 7.15-7.04 (m, 2H), 6.77-6.62 (m, 2H), 4.85-4.77 (m, 1H), 4.18 (s, 2H), 4.12-4.02 (m, 1H), 3.94-3.85 (m, 1H), 2.25-1.95 (m, 4H) ppm. Added the crude Added 30 psi H2 The reaction mixture was purged with nitrogen filtered through Celite™ rinsed with EtOAc The filtrate was concentrated on a rotary evaporator giving a brown oil the reaction three more times on the same scale the batches were combined for purification distilled (ca. 15 ton) collecting the distillate at 108-129° C.

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

Procedure: Placed 5% palladium on carbon (16.3 g, 50% wet, 3.83 mmol, Aldrich 330116) in a Parr bottle under nitrogen, followed by MeOH (100 mL, JT-Baker 909333). Added the crude mixture of 2-(2-nitrophenyl)-2,5-dihydrofuran and 2-(2-nitrophenyl)-2,3-dihydrofuran (3a&3b)) (163 g) dissolved in MeOH (389 mL), followed by NEt3 (237.6 mL, 1.705 mol, Sigma-Aldrich 471283). Placed the vessel on a Parr shaker and saturated with H2. Added 30 psi H2 and shook until consumption complete (LCMS and NMR showed complete reaction). The reaction mixture was purged with nitrogen, filtered through Celite™ and rinsed with EtOAc. The filtrate was concentrated on a rotary evaporator giving a brown oil. Repeated the reaction three more times on the same scale and the batches were combined for purification. The crude product was vacuum distilled (ca. 15 ton) collecting the distillate at 108-129° C. to give (4) as a clear faint yellow oil (427.9 g, average yield was 84%; 98% GCMS purity). LCMS (C18 column eluting with 10-90% CH3CN/water gradient over 5 minutes with formic acid modifier) M+1: 163.95 (1.46 min). 1H NMR (300 MHz, CDCl3): δ 7.15-7.04 (m, 2H), 6.77-6.62 (m, 2H), 4.85-4.77 (m, 1H), 4.18 (s, 2H), 4.12-4.02 (m, 1H), 3.94-3.85 (m, 1H), 2.25-1.95 (m, 4H) ppm. Added the crude Added 30 psi H2 The reaction mixture was purged with nitrogen filtered through Celite™ rinsed with EtOAc The filtrate was concentrated on a rotary evaporator giving a brown oil the reaction three more times on the same scale the batches were combined for purification distilled (ca. 15 ton) collecting the distillate at 108-129° C.

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

Procedure: To a stirring solution of 2-tetrahydrofuran-2-yl-aniline (4) (53.45 g, 327.5 mmol) in methyl tert-butyl ether (MTBE, 641.4 mL) and acetonitrile (213.8 mL) cooled to 2° C. was added N-bromosuccinimide (NBS, 58.88 g, 99%, 327.5 mmol, Aldrich B81255) in 4 portions maintaining internal temperature below about 8° C. The reaction mixture was stirred while cooling with an ice-water bath for 30 minutes (NMR of a worked-up aliquot showed complete consumption of starting material). Aqueous 1 N Na2S2O3 (330 mL) was added to the reaction mixture, removed the cold bath and stirred for 20 minutes. The mixture was diluted with EtOAc and the layers were separated. The organic phase was washed with saturated aqueous NaHCO3 (2×), water, brine, dried over MgSO4, filtered through a short plug of silica, eluted with EtOAc, and concentrated under reduced pressure to give (5) as a very dark amber oil (82.25 g, 77-94% HPLC purity). Carried forward without further purification. LCMS (C18 column eluting with 10-90% CH3CN/water gradient over 5 minutes with formic acid modifier) M+1: 242.10 (2.89 min). 1H NMR (300 MHz, CDCl3) δ 7.22 (d, J=2.3 Hz, 1H), 7.16 (dd, J=8.4, 2.3 Hz, 1H), 6.54 (d, J=8.4 Hz, 1H), 4.79-4.73 (m, 1H), 4.15 (s, 2H), 4.10-4.01 (m, 1H), 3.93-3.85 (m, 1H), 2.26-2.13 (m, 1H), 2.12-1.97 (m, 3H) ppm. maintaining internal temperature below about 8° C while cooling with an ice-water bath for 30 minutes (NMR of complete consumption of starting material) Aqueous 1 N Na2S2O3 (330 mL) was added to the reaction mixture removed the cold bath stirred for 20 minutes The mixture was diluted with EtOAc the layers were separated The organic phase was washed with saturated aqueous NaHCO3 (2×), water, brine dried over MgSO4 filtered through a short plug of silica eluted with EtOAc concentrated under reduced pressure

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

Procedure: 5% Palladium on carbon (16.3 g, 50% wet, 3.83 mmol, Aldrich 330116) was placed in a Parr bottle under nitrogen, followed by MeOH (100 mL, JT-Baker 909333). The crude mixture of 2-(2-nitrophenyl)-2,5-dihydrofuran and 2-(2-nitrophenyl)-2,3-dihydrofuran (3a & 3b) (163 g) dissolved in MeOH (389 mL) was added to the Parr bottle, followed by NEt3 (237.6 mL, 1.705 mol, Sigma-Aldrich 471283). The bottle was placed on a Parr shaker and saturated with H2. 30 psi H2 was added and the bottle was shaken until starting material was completely consumed (LCMS and NMR showed complete reaction). The reaction mixture was purged with nitrogen, filtered through Celite™ and rinsed with EtOAc. The filtrate was concentrated on a rotary evaporator giving a brown oil. The reaction was repeated three more times on the same scale and the batches were combined for purification. The crude product was vacuum distilled (ca. 15 ton) collecting the distillate at 108-129° C. to give (4) as a clear faint yellow oil (427.9 g, average yield was 84%; 98% GCMS purity). LCMS (C18 column eluting with 10-90% CH3CN/water gradient over 5 minutes with formic acid modifier) M+1: 163.95 (1.46 min). 1H NMR (300 MHz, CDCl3) δ 7.15-7.04 (m, 2H), 6.77-6.62 (m, 2H), 4.85-4.77 (m, 1H), 4.18 (s, 2H), 4.12-4.02 (m, 1H), 3.94-3.85 (m, 1H), 2.25-1.95 (m, 4H) ppm. was added to the Parr bottle 30 psi H2 was added was completely consumed (LCMS and NMR showed complete reaction) The reaction mixture was purged with nitrogen filtered through Celite™ rinsed with EtOAc The filtrate was concentrated on a rotary evaporator giving a brown oil the batches were combined for purification distilled (ca. 15 ton) collecting the distillate at 108-129° C.

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

Procedure: 5% Palladium on carbon (16.3 g, 50% wet, 3.83 mmol, Aldrich 330116) was placed in a Parr bottle under nitrogen, followed by MeOH (100 mL, JT-Baker 909333). The crude mixture of 2-(2-nitrophenyl)-2,5-dihydrofuran and 2-(2-nitrophenyl)-2,3-dihydrofuran (3a & 3b) (163 g) dissolved in MeOH (389 mL) was added to the Parr bottle, followed by NEt3 (237.6 mL, 1.705 mol, Sigma-Aldrich 471283). The bottle was placed on a Parr shaker and saturated with H2. 30 psi H2 was added and the bottle was shaken until starting material was completely consumed (LCMS and NMR showed complete reaction). The reaction mixture was purged with nitrogen, filtered through Celite™ and rinsed with EtOAc. The filtrate was concentrated on a rotary evaporator giving a brown oil. The reaction was repeated three more times on the same scale and the batches were combined for purification. The crude product was vacuum distilled (ca. 15 ton) collecting the distillate at 108-129° C. to give (4) as a clear faint yellow oil (427.9 g, average yield was 84%; 98% GCMS purity). LCMS (C18 column eluting with 10-90% CH3CN/water gradient over 5 minutes with formic acid modifier) M+1: 163.95 (1.46 min). 1H NMR (300 MHz, CDCl3) δ 7.15-7.04 (m, 2H), 6.77-6.62 (m, 2H), 4.85-4.77 (m, 1H), 4.18 (s, 2H), 4.12-4.02 (m, 1H), 3.94-3.85 (m, 1H), 2.25-1.95 (m, 4H) ppm. was added to the Parr bottle 30 psi H2 was added was completely consumed (LCMS and NMR showed complete reaction) The reaction mixture was purged with nitrogen filtered through Celite™ rinsed with EtOAc The filtrate was concentrated on a rotary evaporator giving a brown oil the batches were combined for purification distilled (ca. 15 ton) collecting the distillate at 108-129° C.

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

Procedure: 3a and 3b were carried through the reduction step to afford 2-tetrahydrofuran-2-yl-aniline (4) as set forth in Example 1.b (below). Analysis of this material revealed that both 3a and 3b were formed with the same major enantiomer, with an overall 70% ee. It is unknown whether the absolute stereochemistry of the major enantiomer was (R) or (S).

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

Procedure: To a stirring solution of 2-tetrahydrofuran-2-yl-aniline (4) (53.45 g, 327.5 mmol) in methyl tert-butyl ether (MTBE, 641.4 mL) and acetonitrile (213.8 mL) cooled to 2° C. was added N-bromosuccinimide (58.88 g, 99%, 327.5 mmol, Aldrich B81255) in 4 portions maintaining internal temperature below about 8° C. The reaction mixture was stirred while cooling with an ice-water bath for 30 minutes (NMR of a worked-up aliquot showed complete consumption of starting material). Added aqueous 1 N Na2S2O3 (330 mL), removed the cold bath and stirred for 20 minutes. The mixture was diluted with EtOAc and the layers were separated. The organic phase was washed with saturated aqueous NaHCO3 (2×), water, brine, dried over MgSO4, filtered through a short plug of silica, eluted with EtOAc, and concentrated under reduced pressure to give (5) as a very dark amber oil (82.25 g, 77-94% HPLC purity). Carried forward without further purification. LCMS (C18 column eluting with 10-90% CH3CN/water gradient over 5 minutes with formic acid modifier) M+1: 242.10 (2.89 min). 1H NMR (300 MHz, CDCl3) δ 7.22 (d, J=2.3 Hz, 1H), 7.16 (dd, J=8.4, 2.3 Hz, 1H), 6.54 (d, J=8.4 Hz, 1H), 4.79-4.73 (m, 1H), 4A5 (s, 2H), 4.10-4.01 (m, 1H), 3.93-3.85 (m, 1H), 2.26-2.13 (m, 1H), 2.12-1.97 (m, 3H) ppm. maintaining internal temperature below about 8° C while cooling with an ice-water bath for 30 minutes (NMR of complete consumption of starting material) Added aqueous 1 N Na2S2O3 (330 mL), removed the cold bath stirred for 20 minutes The mixture was diluted with EtOAc the layers were separated The organic phase was washed with saturated aqueous NaHCO3 (2×), water, brine dried over MgSO4 filtered through a short plug of silica eluted with EtOAc concentrated under reduced pressure

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

Procedure: Dissolved 33 g of compound (4) into MeOH (265 ml) which resulted in a concentration of approximately 125 mg/ml. The mixture was filtered through a 0.2 micron membrane filter then chromatographed on a ChiralPak® IC column (30 mm×150 mm, column temp 35° C., Chiral Technologies) at 100 bar using a Berger multigram supercritical fluid chromatographic system. Mobile phase was (90:10) CO2:CH3OH eluting at 350 ml/min with UV monitoring at 220 nanometers. Obtained 15.64 g of desired product (4a) as a green oil. Analytical SFC ([90:10] CO2:CH3OH, at 5 ml/min on a ChiralPak IC column (4.6×100 mm) held at 35° C. and run at 100 bar pressure with UV monitoring at 220 nm) showed 95.5% ee with 95% overall purity. resulted in a concentration of approximately 125 mg/ml The mixture was filtered through a 0.2 micron membrane filter then chromatographed on a ChiralPak® IC column (30 mm×150 mm, column temp 35° C., Chiral Technologies) at 100 bar

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

Procedure: Placed 5% palladium on carbon (16.3 g, 50% wet, 3.83 mmol, Aldrich 330116) in a Parr bottle under nitrogen, followed by MeOH (100 mL, JT-Baker 909333). Added the crude mixture of 2-(2-nitrophenyl)-2,5-dihydrofuran and 2-(2-nitrophenyl)-2,3-dihydrofuran (3a&3b)) (163 g) dissolved in MeOH (389 mL), followed by NEt3 (237.6 mL, 1.705 mol, Sigma-Aldrich 471283). Placed the vessel on a Parr shaker and saturated with H2. Added 30 psi H2 and shook until consumption complete (LCMS and NMR showed complete reaction). The reaction mixture was purged with nitrogen, filtered through Celite™ and rinsed with EtOAc. The filtrate was concentrated on a rotary evaporator giving a brown oil. Repeated the reaction three more times on the same scale and the batches were combined for purification. The crude product was vacuum distilled (ca. 15 ton) collecting the distillate at 108-129° C. to give (4) as a clear faint yellow oil (427.9 g, average yield was 84%; 98% GCMS purity). LCMS (C18 column eluting with 10-90% CH3CN/water gradient over 5 minutes with formic acid modifier) M+1: 163.95 (1.46 min). 1H NMR (300 MHz, CDCl3): δ 7.15-7.04 (m, 2H), 6.77-6.62 (m, 2H), 4.85-4.77 (m, 1H), 4.18 (s, 2H), 4.12-4.02 (m, 1H), 3.94-3.85 (m, 1H), 2.25-1.95 (m, 4H) ppm. Added the crude Added 30 psi H2 The reaction mixture was purged with nitrogen filtered through Celite™ rinsed with EtOAc The filtrate was concentrated on a rotary evaporator giving a brown oil the reaction three more times on the same scale the batches were combined for purification distilled (ca. 15 ton) collecting the distillate at 108-129° C.