1-bromopropan-2-ol

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:

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

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

Procedure: The manner in which optically active forms of arylmethoxy aliphatic amines, such as (2S)-N-methyl-1-[(3-aminophenyl)methoxy]-propan-2-amine type compounds, are provided can vary. In one approach, a 3-aminobenzyl alcohol type compound (N-protected as the phthalimide) can be alkylated with a chiral 1-bromo-2-propanol type compound containing an O-protecting group, such as (1S)-2-(2-bromo-1-methylethoxy)tetrahydro-2H-pyran using a base such as sodium hydride and a solvent such as N,N-dimethylformamide or tetrahydrofuran. The tetrahydropyranyl protecting group of the resulting chiral arylmethyl ether type compound can be removed with aqueous sulfuric acid in methanol, affording (2S)-1-[(3-aminophenyl)methoxy]-propan-2-ol. The resulting chiral alcohol intermediate can be converted to its corresponding tosylate, followed by tosylate displacement with methylamine with inversion of configuration, and finally removal of the N-phthaloyl group to give the chiral amine (2R)-N-methyl-1-[(3-aminophenyl)methoxy]-propan-2-amine. Chiral side chain compounds such as (1S)-2-(2-bromo-1-methylethoxy)tetrahydro-2H-pyran can be prepared from (2S)-1-bromo-2-propanol by treatment with 3,4-dihydro-2H-pyran in dichloromethane with p-toluenesulfonic acid as a catalyst according to the method of S. A. M. Nieuwenhuis et al., Tetrahedron 50: 13207-13230 (1994). The required (2S)-1-bromo-2-propanol can be obtained from (S)-propylene oxide (commercially available from Fluka) by treatment with hydrogen bromide in acetic acid at 0° C. The corresponding optical antipode, (2R)-N-methyl-1-[(3-aminophenyl)methoxy]-propan-2-amine can be prepared in an analogous manner from (R)-propylene oxide (commercially available from Fluka) by using the synthetic procedure of S. A. M. Nieuwenhuis et al. to prepare the tetrahydropyranyl ether of (2R)-1-bromo-2-propanol and by using the synthetic sequence described above. containing an O-protecting group The tetrahydropyranyl protecting group of the resulting chiral arylmethyl ether type compound can be removed with aqueous sulfuric acid in methanol

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

Procedure: To a solution of 46 g of phosphorous oxychloride in 110 ml of carbon tetrachloride was added with stirring 21 g of 1-bromo-2-propanol. The mixture was stirred overnight, the solvent removed and the residue evaporated twice from toluene at 35° C., then evaporated to dryness giving a dark oil. This oil was distilled on a Kugelrohr at 75° C., 0.3 mm giving 16.3 g of the desired compound as a white oil. the solvent removed the residue evaporated twice from toluene at 35° C. evaporated to dryness giving a dark oil This oil was distilled on a Kugelrohr at 75° C.

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: tert-Butyl piperidin-4-ylcarbamate (2.0 g, 10.0 mmol), 1-bromopropan-2-ol (2.8 g, 20.0 mmol, commercial product which also contained 30% of the regioisomer 2-bromopropan-1-ol), triethylamine (4.2 mL, 30.0 mmol), and acetonitrile (15 mL) were combined in a microwave vial and heated to 70° C. for 4 hours. The reaction mixture was concentrated to dryness. The crude product was partitioned between ethyl acetate/water. The aqueous phase was re-extracted 2× with ethyl acetate. The combined organic phases were dried over magnesium sulfate, filtered, and concentrated to dryness. The product was purified by flash chromatography on silica gel eluting with a gradient of 20-30% methanol in dichloromethane to give 1.7 g of the desired product as an oil. The reaction mixture was concentrated to dryness The crude product was partitioned between ethyl acetate/water The aqueous phase was re-extracted 2× with ethyl acetate The combined organic phases were dried over magnesium sulfate filtered concentrated to dryness The product was purified by flash chromatography on silica gel eluting with a gradient of 20-30% methanol in dichloromethane

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: tert-Butyl piperidin-4-ylcarbamate (2.0 g, 10.0 mmol), 1-bromopropan-2-ol (2.8 g, 20.0 mmol, commercial product which also contained 30% of the regioisomer 2-bromopropan-1-ol), triethylamine (4.2 mL, 30.0 mmol), and acetonitrile (15 mL) were combined in a microwave vial and heated to 70° C. for 4 hours. The reaction mixture was concentrated to dryness. The crude product was partitioned between ethyl acetate/water. The aqueous phase was re-extracted 2× with ethyl acetate. The combined organic phases were dried over magnesium sulfate, filtered, and concentrated to dryness. The product was purified by flash chromatography on silica gel eluting with a gradient of 20-30% methanol in dichloromethane to give 1.7 g of the desired product as an oil. The reaction mixture was concentrated to dryness The crude product was partitioned between ethyl acetate/water The aqueous phase was re-extracted 2× with ethyl acetate The combined organic phases were dried over magnesium sulfate filtered concentrated to dryness The product was purified by flash chromatography on silica gel eluting with a gradient of 20-30% methanol in dichloromethane