H-D-TYR(BZL)-OH

Crystalline

To an ice cooled solution of potassium hydroxide (80.3 g, 1.22 mol) in 200 ml of water was added D-tyrosine (100 g, 0.55 mol) with maintaining inner side temperature at 15-20 Example 21; Preparation of O-Benzyl-D-Tyrosine; In a dry, 1L three necked round bottom flask was charged water (200 mL) and potassium hydroxide pellets (80.3 g, 1.22 mol) and cooled to ca. 26-28 °C. To this solution D-tyrosine (100 g, 0.55 mol) and copper sulfate pentahydrate (85.5 g, 0.34 mol) was added at ca. 26-28 °C with stirring. The mixture was heated to 60 °C-65 °C with stirring and cooled. DMF (400 mL) was added to it. Benzyl chloride (83. 8 g, 0.66 mol) was added slowly between 50 °C to 60 °C with stirring. Gray coloured solid copper complex of 0-benzyl-D-tyrosine precipitates out. The mixture was cooled to ca. 26-28 °C, stirred and resulting solids were collected by filtration, washed with water and drained well under vacuum. The wet cake of 0-benzyl-D-tyrosine copper complex (200 g) was stirred with methanol at reflux temperature. The solids were filtered and washed with methanol. It was dried in an oven at 65 °C-70 °C. The copper complex of 0-benzyl-D-tyrosine weighed about 150 g. The Cu complex of 0-benzyl-D-tyrosine was added into water in a 30 lit S. S. tank. It was stirred at ca. 26-28 °C. To this slurry 35 percent conc. HC1 (3.32 L) was added with stirring, and the solids obtained were filtered and drained well followed by washing with water and 10 percent ammonia solution. The wet cake was centrifuged and again washed with water. The solids were dried in an oven at 65 °C-70 °C. The off white 0-benzyl-D-tyrosine was obtained in 73 percent yield (110 g)1N Aqueous sodium hydroxide solution (26.2 ml) and copper sulfate (2.09 g) were added to 2R-amino-3-(4-hydroxyphenyl)propionic acid (4.75 g) and the mixture was stirred at room temperature for 1 hr. To this solution were added methanol (158 ml) and 2N aqueous sodium hydroxide solution (13.1 ml), and then benzyl bromide (3.3 ml) was added slowly. The mixture was stirred at room temperature for 3 hr. The product was collected by filtration and the crystals were washed with a mixed solvent of methanol (12.5 ml) and water (12.5 ml). 1N Aqueous hydrochloric acid solution (30 ml) was added to the obtained crystals and the mixture was stirred at 50°C for 30 min. The crystals were collected by filtration and 1N aqueous hydrochloric acid solution (30 ml) was added to the obtained crystals. The mixture was stirred at 50°C for 30 min and the crystals were collected by filtration. The obtained crystals were washed with water (25 ml), after which water (30 ml) was added. The mixture was adjusted to pH 6.3 with sodium hydroxide and the crystals were collected by filtration. The obtained crystals were dried to give 2R-amino-3-(4-benzyloxyphenyl)propionic acid as crystals (3.24 g, yield 46percent).

Molecular Weight:271.31
XLogP3:-0.1
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:6
Exact Mass:271.12084340
Monoisotopic Mass:271.12084340
Topological Polar Surface Area:72.6
Heavy Atom Count:20
Complexity:294
Defined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes