tert-Butyl [(1S,2R)-1-Benzyl-2-hydroxy-3-(isobutylamino)propyl]carbamate

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

Procedure: To a solution of Example 1 (11.86 g) in dichloromethane (100 mL) was added triethylamine (TEA) (19.6 mL, 4 equivalents) followed by dropwise addition of vinylbenzenesulfonyl chloride (8.36 g, 1.2 equivalents) at 25° C. for 3 hrs. The mixture was partitioned in 1N sodium bicarbonate (NaHCO3) and ethyl acetate (EtOAc). The organic extract was concentrated, and the residue was chromatographed on silica gel, eluting with ethyl acetate/hexanes (1:4) to afford the title compound (9.6 g, 54%). 1H NMR (300 MHz, CDCl3): δ ppm 0.87 (d, J=6.44 Hz, 3H), 0.90 (d, J=6.78 Hz, 3H), 1.34 (s, 9H), 1.86 (m, 1H), 2.84 (dd, J=13.39, 6.61 Hz, 2H), 2.97 (m, 3H), 3.11 (m, 3H), 3.79 (s, 1H), 4.61 (s, 1H), 5.44 (d, J=10.85 Hz, 1H), 5.88 (d, J=17.63 Hz, 1H), 6.75 (dd, J=17.63, 10.85 Hz, 1H), 7.25 (m, 5H), 7.51 (d, J=8.48 Hz, 2H), 7.72 (d, J=8.48 Hz, 2H). The mixture was partitioned in 1N sodium bicarbonate (NaHCO3) The organic extract was concentrated the residue was chromatographed on silica gel eluting with ethyl acetate/hexanes (1:4)

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

Procedure: To a solution of Example 1 (11.86 g) in dichloromethane (100 mL) was added triethylamine (TEA) (19.6 mL, 4 equivalents) followed by dropwise addition of vinylbenzenesulfonyl chloride (8.36 g, 1.2 equivalents) at 25° C. for 3 hrs. The mixture was partitioned in 1N sodium bicarbonate (NaHCO3) and ethyl acetate (EtOAc). The organic extract was concentrated, and the residue was chromatographed on silica gel, eluting with ethyl acetate/hexanes (1:4) to afford the title compound (9.6 g, 54%). 1H NMR (300 MHz, CDCl3): δ ppm 0.87 (d, J=6.44 Hz, 3H), 0.90 (d, J=6.78 Hz, 3H), 1.34 (s, 9H), 1.86 (m, 1H), 2.84 (dd, J=13.39, 6.61 Hz, 2H), 2.97 (m, 3H), 3.11 (m, 3H), 3.79 (s, 1H), 4.61 (s, 1H), 5.44 (d, J=10.85 Hz, 1H), 5.88 (d, J=17.63 Hz, 1H), 6.75 (dd, J=17.63, 10.85 Hz, 1H), 7.25 (m, 5H), 7.51 (d, J=8.48 Hz, 2H), 7.72 (d, J=8.48 Hz, 2H). The mixture was partitioned in 1N sodium bicarbonate (NaHCO3) The organic extract was concentrated the residue was chromatographed on silica gel eluting with ethyl acetate/hexanes (1:4)

Conditions: temp:62.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 7.5 g (22.3 mmol) of (1S,2R)-(1-benzyl-2-hydroxy-3-isobutylamino-propyl)-carbamic acid tert-butyl ester and 2.7 g (26.8 mmol, 1.2 equiv) of triethylamine are dissolved in 100 g of isopropanol and heated to 60-65° C. 5.41 g (24.5 mmol, 1.1 eq) p-nitrophenyl-sulfonyl chloride are added in several portions within 30 minutes. The reaction mixture is kept at 60° C. for another 30 minutes. 10 g of water are added and the suspension is stirred for an additional 30 minutes at 60° C. The mixture is cooled to 25° C. within 90 min and the product is filtered off, washed with a mixture of isopropanol/water (1:1 v/v) and dried under vacuum to yield 11.23 g (96.5%) of white (1S,2R)-{1-benzyl-2-hydroxy-3-[isobutyl-(4-nitro-benzenesulfonyl)-amino]-propyl}-carbamic acid tert-butyl ester. The mixture is cooled to 25° C. within 90 min the product is filtered off washed with a mixture of isopropanol/water (1:1 v/v) dried under vacuum

Conditions: temp:62.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 7.5 g (22.3 mmol) of (1S,2R)-(1-benzyl-2-hydroxy-3-isobutylamino-propyl)-carbamic acid tert-butyl ester and 2.7 g (26.8 mmol, 1.2 equiv) of triethylamine are dissolved in 100 g of isopropanol and heated to 60-65° C. 5.41 g (24.5 mmol, 1.1 eq) p-nitrophenyl-sulfonyl chloride are added in several portions within 30 minutes. The reaction mixture is kept at 60° C. for another 30 minutes. 10 g of water are added and the suspension is stirred for an additional 30 minutes at 60° C. The mixture is cooled to 25° C. within 90 min and the product is filtered off, washed with a mixture of isopropanol/water (1:1 v/v) and dried under vacuum to yield 11.23 g (96.5%) of white (1S,2R)-{1-benzyl-2-hydroxy-3-[isobutyl-(4-nitro-benzenesulfonyl)-amino]-propyl}-carbamic acid tert-butyl ester. The mixture is cooled to 25° C. within 90 min the product is filtered off washed with a mixture of isopropanol/water (1:1 v/v) dried under vacuum

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (1S,2R)-tert-butyl N-[1-benzyl-2-hydroxy-3-(isobutylamino)propyl]carbamate (127.77 g, 379.7 mmol) was heated in toluene (888 ml) to 80° C. and triethylamine (42.6 g, 417.8 mmol) added. The mixture was heated to 90° C. and a solution of p-nitrobenzene sulphonyl chloride (94.3 g, 425.4 mmol) in toluene (250 ml) was added over 30 minutes then stirred for a further 2 hours. The resultant solution of the nosylated intermediate {(1S,2R)-tert-butyl N-[1-benzyl-2-hydroxy-3-(N-isobutyl- 4-nitrobenzenesulphonamido)propyl]carbamate } was then cooled to 80° C. The solution was maintained at approximately 80° C., and concentrated hydrochloric acid (31.4 ml, 376.8 mmol) was added over 20 minutes. The mixture was heated to reflux (approx 86° C.) and maintained at this temperature for an hour then a further quantity of concentrated hydrochloric acid (26.4 ml, 316.8 mmol) was added. Solvent (water and toluene mixture) was removed from the reaction mixture by azeotropic distillation (total volume of solvent removed approx 600 ml), and the resultant suspension was cooled to 70-75° C. Denatured ethanol (600 ml) was added, and the solution was cooled to 20° C. The mixture was further cooled to approximately −10° C. and the precipitate formed was isolated by filtration, washed with denatured ethanol (50 ml) and dried at approximately 50° C., under vacuum, for approximately 12 hours, to give (2R,3S)-N-(3-amino-2-hydroxy-4-phenylbutyl)-N-isobutyl-4-nitrobenzene sulphonamide hydrochloride (160 g; 73% of theory yield corrected for assay). NMR: 1H NMR (300Mhz, dmso-d6): 8.37(2H, d, J=9 Hz), 8.16(NH3+s), 8.06(2H, d, J=9 Hz), 7.31(5H, m), 5.65(1H, d, J=5 Hz), 3.95(1H, m), 3.39(2H, m), 2.95(5H, m), 1.90(1H, m), 0.77(6H, dd, J=21 Hz and 6 Hz). The solution was maintained at approximately 80° C. The mixture was heated to reflux (approx 86° C.) maintained at this temperature for an hour Solvent (water and toluene mixture) was removed from the reaction mixture by azeotropic distillation (total volume of solvent removed approx 600 ml) the resultant suspension was cooled to 70-75° C Denatured ethanol (600 ml) was added the solution was cooled to 20° C The mixture was further cooled to approximately −10° C. the precipitate formed was isolated by filtration washed with denatured ethanol (50 ml) dried at approximately 50° C., under vacuum, for approximately 12 hours

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

Procedure: To a solution of Example 1 (11.86 g) in dichloromethane (100 mL) was added triethylamine (TEA) (19.6 mL, 4 equivalents) followed by dropwise addition of vinylbenzenesulfonyl chloride (8.36 g, 1.2 equivalents) at 25° C. for 3 hrs. The mixture was partitioned in 1N sodium bicarbonate (NaHCO3) and ethyl acetate (EtOAc). The organic extract was concentrated, and the residue was chromatographed on silica gel, eluting with ethyl acetate/hexanes (1:4) to afford the title compound (9.6 g, 54%). 1H NMR (300 MHz, CDCl3): δ ppm 0.87 (d, J=6.44 Hz, 3H), 0.90 (d, J=6.78 Hz, 3H), 1.34 (s, 9H), 1.86 (m, 1H), 2.84 (dd, J=13.39, 6.61 Hz, 2H), 2.97 (m, 3H), 3.11 (m, 3H), 3.79 (s, 1H), 4.61 (s, 1H), 5.44 (d, J=10.85 Hz, 1H), 5.88 (d, J=17.63 Hz, 1H), 6.75 (dd, J=17.63, 10.85 Hz, 1H), 7.25 (m, 5H), 7.51 (d, J=8.48 Hz, 2H), 7.72 (d, J=8.48 Hz, 2H). The mixture was partitioned in 1N sodium bicarbonate (NaHCO3) The organic extract was concentrated the residue was chromatographed on silica gel eluting with ethyl acetate/hexanes (1:4)

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

Procedure: To a solution of Example 1 (11.86 g) in dichloromethane (100 mL) was added triethylamine (TEA) (19.6 mL, 4 equivalents) followed by dropwise addition of vinylbenzenesulfonyl chloride (8.36 g, 1.2 equivalents) at 25° C. for 3 hrs. The mixture was partitioned in 1N sodium bicarbonate (NaHCO3) and ethyl acetate (EtOAc). The organic extract was concentrated, and the residue was chromatographed on silica gel, eluting with ethyl acetate/hexanes (1:4) to afford the title compound (9.6 g, 54%). 1H NMR (300 MHz, CDCl3): δ ppm 0.87 (d, J=6.44 Hz, 3H), 0.90 (d, J=6.78 Hz, 3H), 1.34 (s, 9H), 1.86 (m, 1H), 2.84 (dd, J=13.39, 6.61 Hz, 2H), 2.97 (m, 3H), 3.11 (m, 3H), 3.79 (s, 1H), 4.61 (s, 1H), 5.44 (d, J=10.85 Hz, 1H), 5.88 (d, J=17.63 Hz, 1H), 6.75 (dd, J=17.63, 10.85 Hz, 1H), 7.25 (m, 5H), 7.51 (d, J=8.48 Hz, 2H), 7.72 (d, J=8.48 Hz, 2H). The mixture was partitioned in 1N sodium bicarbonate (NaHCO3) The organic extract was concentrated the residue was chromatographed on silica gel eluting with ethyl acetate/hexanes (1:4)

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

Procedure: To a solution of Example 1 (11.86 g) in dichloromethane (100 mL) was added triethylamine (TEA) (19.6 mL, 4 equivalents) followed by dropwise addition of vinylbenzenesulfonyl chloride (8.36 g, 1.2 equivalents) at 25° C. for 3 hrs. The mixture was partitioned in 1N sodium bicarbonate (NaHCO3) and ethyl acetate (EtOAc). The organic extract was concentrated, and the residue was chromatographed on silica gel, eluting with ethyl acetate/hexanes (1:4) to afford the title compound (9.6 g, 54%). 1H NMR (300 MHz, CDCl3): δ ppm 0.87 (d, J=6.44 Hz, 3H), 0.90 (d, J=6.78 Hz, 3H), 1.34 (s, 9H), 1.86 (m, 1H), 2.84 (dd, J=13.39, 6.61 Hz, 2H), 2.97 (m, 3H), 3.11 (m, 3H), 3.79 (s, 1H), 4.61 (s, 1H), 5.44 (d, J=10.85 Hz, 1H), 5.88 (d, J=17.63 Hz, 1H), 6.75 (dd, J=17.63, 10.85 Hz, 1H), 7.25 (m, 5H), 7.51 (d, J=8.48 Hz, 2H), 7.72 (d, J=8.48 Hz, 2H). The mixture was partitioned in 1N sodium bicarbonate (NaHCO3) The organic extract was concentrated the residue was chromatographed on silica gel eluting with ethyl acetate/hexanes (1:4)

Conditions: temp:42.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: [(1S,2R)-3-[(2-methylpropyl)amino]-2-hydroxy-1-(phenyl methyl)propyl]carbamic acid tert-butyl ester (4, 100 gm) and triethylamine (39.04 g) was added to methylenedichloride (1200 mL) and the temperature was raised to 40° C. p-nitro benzene sulfonyl chloride solution (72.3 g of p-NBSC dissolve in 300 mL methylenedichloride) was added slowly at 40-45° C. for 2-3 hrs. The reaction was maintained for 3 hours at 40-45° C. After completion of the reaction, water (500 mL) was added, separated the organic layer and distilled out methylene dichloride at atmospheric pressure. Finally, strip out the methylene dichloride by using isopropyl alcohol (200 mL). Isopropyl alcohol (1000 mL) was added to the distillate and maintained the stirring for 60 minutes at 70-80° C. Cooled the mass to 30-35° C., filtered and washed with Isopropyl alcohol to get title compound 3 (yield 145 g). was added slowly at 40-45° C. for 2-3 hrs was added separated the organic layer distilled out methylene dichloride at atmospheric pressure Isopropyl alcohol (1000 mL) was added to the distillate maintained the stirring for 60 minutes at 70-80° C Cooled the mass to 30-35° C. filtered washed with Isopropyl alcohol

Conditions: temp:62.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The mixture of [(1S,2S)-3-chloro-2-hydroxy-1-(phenylmethyl)propyl]carbamic acid tert-butyl ester (5, 100 g), isobutyl amine (294 g), sodium carbonate (31.3 g) and water was heated to 60-65° C. and maintained for 3 hours. After completion of reaction water (200 mL) was added and distilled out excess isobutyl amine under vacuum at below 75° C. Water (800 mL) was added to the distillate, cooled to 25-35° C. and stirred for 2 hours. The obtained solid was filtered and washed with water to get title compound 4 (yield 105 g). maintained for 3 hours was added distilled out excess isobutyl amine under vacuum at below 75° C Water (800 mL) was added to the distillate cooled to 25-35° C. The obtained solid was filtered washed with water

Conditions: temp:62.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 7.5 g (22.3 mmol) of (1S,2R)-(1-benzyl-2-hydroxy-3-isobutylamino-propyl)-carbamic acid tert-butyl ester and 2.7 g (26.8 mmol, 1.2 equiv) of triethylamine are dissolved in 100 g of isopropanol and heated to 60-65° C. 5.41 g (24.5 mmol, 1.1 eq) p-nitrophenyl-sulfonyl chloride are added in several portions within 30 minutes. The reaction mixture is kept at 60° C. for another 30 minutes. 10 g of water are added and the suspension is stirred for an additional 30 minutes at 60° C. The mixture is cooled to 25° C. within 90 min and the product is filtered off, washed with a mixture of isopropanol/water (1:1 v/v) and dried under vacuum to yield 11.23 g (96.5%) of white (1S,2R)-{1-benzyl-2-hydroxy-3-[isobutyl-(4-nitro-benzenesulfonyl)-amino]-propyl}-carbamic acid tert-butyl ester. The mixture is cooled to 25° C. within 90 min the product is filtered off washed with a mixture of isopropanol/water (1:1 v/v) dried under vacuum

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (1S,2R)-tert-butyl N-[1-benzyl-2-hydroxy-3-(isobutylamino)propyl]carbamate (127.77 g, 379.7 mmol) was heated in toluene (888 ml) to 80° C. and triethylamine (42.6 g, 417.8 mmol) added. The mixture was heated to 90° C. and a solution of p-nitrobenzene sulphonyl chloride (94.3 g, 425.4 mmol) in toluene (250 ml) was added over 30 minutes then stirred for a further 2 hours. The resultant solution of the nosylated intermediate {(1S,2R)-tert-butyl N-[1-benzyl-2-hydroxy-3-(N-isobutyl- 4-nitrobenzenesulphonamido)propyl]carbamate } was then cooled to 80° C. The solution was maintained at approximately 80° C., and concentrated hydrochloric acid (31.4 ml, 376.8 mmol) was added over 20 minutes. The mixture was heated to reflux (approx 86° C.) and maintained at this temperature for an hour then a further quantity of concentrated hydrochloric acid (26.4 ml, 316.8 mmol) was added. Solvent (water and toluene mixture) was removed from the reaction mixture by azeotropic distillation (total volume of solvent removed approx 600 ml), and the resultant suspension was cooled to 70-75° C. Denatured ethanol (600 ml) was added, and the solution was cooled to 20° C. The mixture was further cooled to approximately −10° C. and the precipitate formed was isolated by filtration, washed with denatured ethanol (50 ml) and dried at approximately 50° C., under vacuum, for approximately 12 hours, to give (2R,3S)-N-(3-amino-2-hydroxy-4-phenylbutyl)-N-isobutyl-4-nitrobenzene sulphonamide hydrochloride (160 g; 73% of theory yield corrected for assay). NMR: 1H NMR (300Mhz, dmso-d6): 8.37(2H, d, J=9 Hz), 8.16(NH3+s), 8.06(2H, d, J=9 Hz), 7.31(5H, m), 5.65(1H, d, J=5 Hz), 3.95(1H, m), 3.39(2H, m), 2.95(5H, m), 1.90(1H, m), 0.77(6H, dd, J=21 Hz and 6 Hz). The solution was maintained at approximately 80° C. The mixture was heated to reflux (approx 86° C.) maintained at this temperature for an hour Solvent (water and toluene mixture) was removed from the reaction mixture by azeotropic distillation (total volume of solvent removed approx 600 ml) the resultant suspension was cooled to 70-75° C Denatured ethanol (600 ml) was added the solution was cooled to 20° C The mixture was further cooled to approximately −10° C. the precipitate formed was isolated by filtration washed with denatured ethanol (50 ml) dried at approximately 50° C., under vacuum, for approximately 12 hours