ethyl (3R)-3-amino-3-phenylpropanoate

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 25 ml flask, 13.0 g of D-β-phenylalanine ethyl ester was charged under nitrogen, and sodium-potassium alloy (Na : K = 56 : 44 by weight) (0.1 g) was added thereto. The mixture was stirred at 20°C for 3 hours. The reaction mixture was treated as in Example 11 to give 12.1 g of racemic β-phenylalanine ethyl ester. B.P. 95° to 96°C/0.6 mmHg. [α]D25 -0.1° (neat). The reaction mixture was treated as in Example 11

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

Procedure: To a solution of 2,6-dichloro-3-nitro-pyridine (0.75 g, 3.58 mmol) in DMF (30 ml) were added (R)-3-amino-3-phenylpropanoic acid ethyl ester (0.83 g, 4.29 mmol) and DIPEA (1.25 ml, 7.15 mmol). The reaction mixture was stirred at 70° C. overnight after which time it was poured into water (200 ml) and EtOAc. The layers were separated and the aqueous phase was extracted once more with EtOAc. The combined organics were washed with water twice and dried (MgSO4). Filtered and concentrated to give the crude product as an orange oil which was then purified by silica gel flash column chromatography (12 g silica gel, 5% EtOAc/Hexane) to afford 0.80 g (64%) of the title compound as a orange oil which was used without further purification. The layers were separated the aqueous phase was extracted once more with EtOAc The combined organics were washed with water twice dried (MgSO4) Filtered concentrated to give the crude product as an orange oil which was then purified by silica gel flash column chromatography (12 g silica gel, 5% EtOAc/Hexane)

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

Procedure: In this example, 0.32 ml of the diphenyl-diketo-pyridine-18-crown-6 was coated on polystyrene, and further coated with CH2Cl2, as described in Example 4. The resulting coated ligand-bound solid support was then placed in a column. A 25° C. 3 ml racemic source solution containing 50 mMolar R and S enantiomers of the ethyl ester of β-phenylalanine, 0.01 M HClO4, and 0.5 M LiClO4 was drawn through the column at a 0.012 ml/min flow rate. Next, a 2 ml aqueous solution of 0.5 M LiCO4 and 0.01 M HClO4 was passed through the column to wash out the loading solution remaining in the column. The β-phenylalanine ester loaded on the column was then eluted in 3 ml of deionized water at 25° C. at a flow rate of from 0.01–0.02 ml/min in two 1.5 ml aliquots. A 25° C to wash out the loading solution was then eluted in 3 ml of deionized water at 25° C. at a flow rate of from 0.01–0.02 ml/min in two 1.5 ml aliquots

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 25 ml flask, 13.0 g of D-β-phenylalanine ethyl ester was charged under nitrogen, and sodium-potassium alloy (Na : K = 56 : 44 by weight) (0.1 g) was added thereto. The mixture was stirred at 20°C for 3 hours. The reaction mixture was treated as in Example 11 to give 12.1 g of racemic β-phenylalanine ethyl ester. B.P. 95° to 96°C/0.6 mmHg. [α]D25 -0.1° (neat). The reaction mixture was treated as in Example 11