ethyl 3-phenylpropanoate

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:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Dissolve diisopropylamine (3.5 mL, 25 mmol) in tetrahydrofuran (30 mL). Add n-butyllithium (14 mL of a 1.6 M solution in hexane, 22.4 mmol). Stir for 15 minutes and cool to -78° C. Add, by dropwise addition, ethyl dihydrocinnamate (3.5 mL, 20 mmol) and stir for 30 minutes. Add t-butyl bromoacetate (4.0 mL, 25 mmol) and gradually warm to room temperature overnight. Quench the solution with ammonium chloride solution (10 mL) and partition between water (25 mL) and ethyl ether (50 mL). Separate the organic phase, dry (MgSO4) and evaporate the solvent in vacuo. Purify by silica gel chromatography (5% ethyl acetate/hexane) to give 3-phenyl-2-t-butylcarboxymethylpropionic acid, ethyl ester as a pale yellow oil (2.68 g, 46%). stir for 30 minutes Quench the solution with ammonium chloride solution (10 mL) partition between water (25 mL) and ethyl ether (50 mL) Separate the organic phase dry (MgSO4) evaporate the solvent in vacuo Purify by silica gel chromatography (5% ethyl acetate/hexane)

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

Procedure: The dimethyl 3-methyl-2-oxobutylphosphonate (b.p. 125°-135° C./11 mm.Hg; νmax 2950 cm-1, 1710 cm-1, 1470 cm-1, 1260 cm-1, 820 cm-1), used as a starting material in the above preparation, was prepared by proceeding in a similar manner to that hereinbefore described in Example 9(iv) for the preparation of dimethyl 2-oxo-4-phenylbutylphosphonate, but substituting the appropriate quantity of ethyl isobutyrate for the ethyl β-phenylpropionate used as starting material. was prepared

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

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Dissolve diisopropylamine (3.5 mL, 25 mmol) in tetrahydrofuran (30 mL). Add n-butyllithium (14 mL of a 1.6M solution in hexane, 22.4 mmol). Stir for 15 minutes and cool to -78° C. Add, by dropwise addition, ethyl dihydrocinnamate (3.5 mL, 20 mmol) and stir for 30 minutes. Add t-butyl bromoacetate (4.0 mL, 25 mmol) and gradually warm to room temperature overnight. Quench the solution with ammonium chloride solution (10 mL) and partition between water (25 mL) and ethyl ether (50 mL). Separate the organic phase, dry (MgSO4) and evaporate the solvent in vacuo. Purify by silica gel chromatography (5% ethyl acetate/hexane) to give 3-phenyl-2-t-butylcarboxymethylpropionic acid, ethyl ester as a pale yellow oil (2.68 g, 46%). stir for 30 minutes Quench the solution with ammonium chloride solution (10 mL) partition between water (25 mL) and ethyl ether (50 mL) Separate the organic phase dry (MgSO4) evaporate the solvent in vacuo Purify by silica gel chromatography (5% ethyl acetate/hexane)

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

Procedure: A solution of dimethyl methylphosphonate (115.5 g.) in 2.1 l. of tetrahydrofuran is treated, while stirring at -65° C., with a solution of butyl lithium (660 ml. 1.6 M. in hexane). A solution of ethyl hydrocinnamate (93.5 g.) in 225 ml. of tetrahydrofuran is added at -65° C. Stirring is continued at -65° C. for 2 hrs. and then at about 25° C. for 16 hrs. Acetic acid (70 ml.) is added and the mixture concentrated under reduced pressure. The residue is partitioned between dichloromethane and water. The organic phase is dried and concentrated. Distillation yields the title compound, b. 188°-191° C./2 mm., having a mass spectral peak at 256. and then at about 25° C. for 16 hrs the mixture concentrated under reduced pressure The residue is partitioned between dichloromethane and water The organic phase is dried concentrated Distillation

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

Procedure: A solution of dimethyl methylphosphonate (12.4 g., 0.1 mole) in dry tetrahydrofuran (75 ml.) is stirred, maintained under a nitrogen atmosphere, cooled to -50° C., and treated with a 2 N solution of n-butyl lithium in hexane (50 ml., 0.1 mole) added dropwise. Upon completing the addition, the reaction mixture is kept at -50° C. for 1/2 hour to ensure anion formation and then is treated with ethyl 3phenylpropionate (8.9 g., 0.05 mole) added dropwise at -50° C. After stirring for an additional 11/2 hours at -50° to -40° C., the reaction mixture is poured into ice water (250 ml.) providing a turbid solution which is acidified with 2 N hydrochloric acid and extracted with ethyl acetate (4 × 75 ml.). The combined organic extract is dried over sodium sulfate and filtered. Evaporation of the filtrate in vacuo at 40° to 50° C. leaves an oily residue which is distilled to provide the title compound as an oil (11.0 g., 86%), b.p. 148°-150° C./0.1 mm. maintained under a nitrogen atmosphere added dropwise the addition added dropwise at -50° C providing a turbid solution which extracted with ethyl acetate (4 × 75 ml.) The combined organic extract is dried over sodium sulfate filtered Evaporation of the filtrate in vacuo at 40° to 50° C. leaves an oily residue which is distilled

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

Procedure: A solution of dimethyl methylphosphonate (115.5 g.) in 2.1 l. of tetrahydrofuran is treated, while stirring at -65° C., with a solution of butyl lithium (660 ml. 1.6 M. in hexane). A solution of ethyl hydrocinnamate (93.5 g.) in 225 ml. of tetrahydrofuran is added at -65° C. Stirring is continued at -65° C. for 2 hrs. and then at about 25° C. for 16 hrs. Acetic acid (70 ml.) is added and the mixture concentrated under reduced pressure. The residue is partitioned between dichloromethane and water. The organic phase is dried and concentrated. Distillation yields the title compound, b. 188°-191° C./2 mm., having a mass spectral peak at 256. and then at about 25° C. for 16 hrs the mixture concentrated under reduced pressure The residue is partitioned between dichloromethane and water The organic phase is dried concentrated Distillation

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

Procedure: A solution of dimethyl methylphosphonate (115.5 g.) in 2.1 l. of tetrahydrofuran is treated, while stirring at -65° C., with a solution of butyl lithium (660 ml. 1.6 M. in hexane). A solution of ethyl hydrocinnamate (93.5 g.) in 225 ml. of tetrahydrofuran is added at -65° C. Stirring is continued at -65° C. for 2 hrs. and then at about 25° C. for 16 hrs. Acetic acid (70 ml.) is added and the mixture concentrated under reduced pressure. The residue is partitioned between dichloromethane and water. The organic phase is dried and concentrated. Distillation yields the title compound, b. 188°-191° C./2 mm., having a mass spectral peak at 256. and then at about 25° C. for 16 hrs the mixture concentrated under reduced pressure The residue is partitioned between dichloromethane and water The organic phase is dried concentrated Distillation