methyl (2R)-2-isocyanato-3-phenylpropanoate

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 2-phenyl-benzofuran-5-carboxylic acid methyl ester27 (0.7 g, 2.8 mmol) in THF (15 ml) was added dropwise a solution of lithium aluminum hydride (1M in THF) (3.6 ml, 3.6 mmol) at 0° C. After the addition, the reaction mixture was allowed to warm to room temperature and stirred for 2 hrs. The mixture was cooled to 0° C., diluted with ether and sodium sulfate decahydrate was added. After filtration the solids were washed with ether, and the organic layer was washed and dried. Evaporation of the solvent and purification by chromatography yielded (2-phenyl-benzofuran-5-yl)-methanol (0.55 g). A mixture of (2-phenyl-benzofuran-5-yl)-methanol (0.5 g, 2.23 mmol), (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5 (0.55 g, 2.68 mmol), triethylamine (0.74 ml, 5.35 mmol) and THF (15 ml) was heated at 50° C. for 6 hrs. Additional (R) 2-isocyanato-3-phenyl-propionic acid methyl ester 5 (0.15 g) was added, and the mixture was stirred at 50° C. overnight. The solvent was evaporated and the residue was partitioned between ethyl acetate and water. After extraction and evaporation of the solvent, the residue was purified by chromatography to give about 0.76 g of (R)-3-phenyl-2-(2-phenyl-benzofuran-5-ylmethoxycarbonylamino)-propionic acid methyl ester 28. The solvent was evaporated the residue was partitioned between ethyl acetate and water After extraction and evaporation of the solvent the residue was purified by chromatography

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2-hydroxymethyl-5-thiophen-3-yl-benzofuran 22 (0.31 g, 1.35 mmole), (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5 (0.33 g, 1.6 mmole), triethylamine (0.43 ml), and THF (25 ml) was heated to 50° C. under a nitrogen atmosphere for 14 hrs. The solvent was removed under reduced pressure and the residue was purified by chromatography giving about 0.28 g of (R)-2-(5-thiophen-3-yl-benzofuran-2-ylmethoxycarbonylamino)-3-phenylpropionic acid methyl ester 23, mp. 105-106° C. The solvent was removed under reduced pressure the residue was purified by chromatography

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2-hydroxymethyl-5-thiophen-3-yl-benzofuran 22 (0.31 g, 1.35 mmole), (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5 (0.33 g, 1.6 mmole), triethylamine (0.43 ml), and THF (25 ml) was heated to 50° C. under a nitrogen atmosphere for 14 hrs. The solvent was removed under reduced pressure and the residue was purified by chromatography giving about 0.28 g of (R)-2-(5-thiophen-3-yl-benzofuran-2-ylmethoxycarbonylamino)-3-phenylpropionic acid methyl ester 23, mp. 105-106° C. The solvent was removed under reduced pressure the residue was purified by chromatography

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2-hydroxmethyl-5-phenyl-benzofuran 17 (1.20 g, 5.85 mmole), (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5 (1.2 g, 5.9 mmole), triethylamine (1.7 ml), and THF (30 ml) was heated to 50° C. under a nitrogen atmosphere for 6 hrs. The solvent was removed under reduced pressure and the residue was purified by chromatography giving about 1.6 g of (R)-2-(phenyl-benzofuran-2-ylmethoxycarbonylamino)-3-phenyl-propionic acid methyl ester 18, mp. 85-86° C. The solvent was removed under reduced pressure the residue was purified by chromatography

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2-hydroxmethyl-5-phenyl-benzofuran 17 (1.20 g, 5.85 mmole), (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5 (1.2 g, 5.9 mmole), triethylamine (1.7 ml), and THF (30 ml) was heated to 50° C. under a nitrogen atmosphere for 6 hrs. The solvent was removed under reduced pressure and the residue was purified by chromatography giving about 1.6 g of (R)-2-(phenyl-benzofuran-2-ylmethoxycarbonylamino)-3-phenyl-propionic acid methyl ester 18, mp. 85-86° C. The solvent was removed under reduced pressure the residue was purified by chromatography

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

Procedure: (4-Phenethyloxyphenyl)methanol 11(1.141 g, 5.0 mmol), (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5 (1.036 g, 5.0 mmol) and DMAP (10 mg) were combined and heated until molten and stirred for 20 min. Upon cooling the residue was purified by chromatography to give about 2.1 g of (R)-2-(4-phenethyloxybenzyloxycarbonylamino)-3-phenyl-propionic acid methyl ester 12. heated Upon cooling the residue was purified by chromatography

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

Procedure: (R)-Phenylalanine methyl ester hydrochloride (6.5 g, 30 mmol) was dissolved in methylene chloride and cooled to 0C. Phosgene (2M in toluene, 21.0 ml, 42.0 mmol) was added followed by pyridine (9.0 ml, 111 mmol). The mixture was allowed to warm to room temperature and was stirred for three hours. The mixture was then poured into dilute HCl. The layers were separated. The organic extracts were washed, dried, and concentrated to give about 5.8 g of a clear oil of (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5. 4-Phenoxymethylphenylmethanol 4 (0.857 g, 4.0 mmol), (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5 (1.026 g, 5.0 mmol) and 4-dimethylaminopyridine (DMAP) (10 mg) were combined, heated until molten, and stirred for 20 min. Upon cooling, the residue was purified by chromatography to give about 1.6 g of (R)-2-(4-phenoxymethyl-benzyloxycarbonylamino)-3-phenyl-propionic acid methyl ester 6. heated Upon cooling the residue was purified by chromatography

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 2-phenyl-benzofuran-5-carboxylic acid methyl ester 27 (0.7 g, 2.8 mmol) in THF (15 ml) was added dropwise a solution of lithium aluminum hydride (1M in THF) (3.6 ml, 3.6 mmol) at 0° C. After the addition, the reaction mixture was allowed to warm to room temperature and stirred for 2 hrs. The mixture was cooled to 0° C., diluted with ether and sodium sulfate decahydrate was added. After filtration the solids were washed with ether, and the organic layer was washed and dried. Evaporation of the solvent and purification by chromatography yielded (2-phenyl-benzofuran-5-yl)-methanol (0.55 g). A mixture of (2-phenyl-benzofuran-5-yl)-methanol (0.5 g, 2.23 mmol), (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5 (0.55 g, 2.68 mmol), triethylamine (0.74 ml, 5.35 mmol) and THF (15 ml) was heated at 50° C. for 6 hrs. Additional (R) 2-isocyanato-3-phenyl-propionic acid methyl ester 5 (0.15 g) was added, and the mixture was stirred at 50° C. overnight. The solvent was evaporated and the residue was partitioned between ethyl acetate and water. After extraction and evaporation of the solvent, the residue was purified by chromatography to give about 0.76 g of (R)-3-phenyl-2-(2-phenyl-benzofuran-5-ylmethoxycarbonylamino)-propionic acid methyl ester 28. The solvent was evaporated the residue was partitioned between ethyl acetate and water After extraction and evaporation of the solvent the residue was purified by chromatography

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2-hydroxymethyl-5-thiophen-3-yl-benzofuran 22 (0.31 g, 1.35 mmole), (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5 (0.33 g, 1.6 mmole), triethylamine (0.43 ml), and THF (25 ml) was heated to 50° C. under a nitrogen atmosphere for 14 hrs. The solvent was removed under reduced pressure and the residue was purified by chromatography giving about 0.28 g of (R)-2-(5-thiophen-3-yl-benzofuran-2-ylmethoxycarbonylamino)-3-phenylpropionic acid methyl ester 23, mp. 105-106° C. The solvent was removed under reduced pressure the residue was purified by chromatography

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2-hydroxmethyl-5-phenyl-benzofuran 17 (1.20 g, 5.85 mmole), (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5 (1.2 g, 5.9 mmole), triethylamine (1.7 ml), and THF (30 ml) was heated to 50° C. under a nitrogen atmosphere for 6 hrs. The solvent was removed under reduced pressure and the residue was purified by chromatography giving about 1.6 g of (R)-2-(phenyl-benzofuran-2-ylmethoxycarbonylamino)-3-phenyl-propionic acid methyl ester 18, mp. 85-86° C. The solvent was removed under reduced pressure the residue was purified by chromatography

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

Procedure: (4-Phenethyloxyphenyl)methanol 11(1.141 g, 5.0 mmol), (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5 (1.036 g, 5.0 mmol) and DMAP (10 mg) were combined and heated until molten and stirred for 20 min. Upon cooling the residue was purified by chromatography to give about 2.1 g of (R)-2-(4-phenethyloxybenzyloxycarbonylamino)-3-phenyl-propionic acid methyl ester 12. heated Upon cooling the residue was purified by chromatography

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

Procedure: 4-Phenoxymethylphenylmethanol 4 (0.857 g, 4.0 mmol), (R)-2-isocyanato-3-phenyl-propionic acid methyl ester 5 (1.026 g, 5.0 mmol) and 4-dimethylaminopyridine (DMAP) (10 mg) were combined, heated until molten, and stirred for 20 min. Upon cooling, the residue was purified by chromatography to give about 1.6 g of (R)-2-(4-phenoxymethyl-benzyloxycarbonylamino)-3-phenyl-propionic acid methyl ester 6. heated Upon cooling the residue was purified by chromatography