benzyl 3-oxopentanoate

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: Following the procedure of Weiler, J. Am. Chem. Soc. 1974, 96, 1082, benzyl acetoacetate, 7.68 g (40 mmol) was added dropwise to a 0° C. suspension of sodium hydride (2.1 g of 50% dispersion, 42 mmol) in THF (100 mL). After stirring for 10 minutes n-butyl lithium (16 mL of 2.5 M in hexane) was added and the mixture was aged for an additional 10 minutes. At this time iodomethane (2.74 mL, 44 mmol) in THF (4 mL) was added dropwise and the mixture aged 1 hour while slowly warming to room temperature. Work-up was achieved by quenching at 0° C. with 1N HCl, extracting with ether, washing the ether with aqueous NaHCO3, brine, and drying with MgSO4. Removal of the solvent yielded benzyl 3-oxopentanoate. was added the mixture aged 1 hour by quenching at 0° C. with 1N HCl extracting with ether washing the ether with aqueous NaHCO3, brine drying with MgSO4 Removal of the solvent

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

Procedure: Following the procedure of Weiler, J. Am. Chem. Soc. 1974, 96, 1082, benzyl acetoacetate, 7.68 g (40 mmol) was added dropwise to a 0° C. suspension of sodium hydride (2.1 g of 50% dispersion, 42 mmol) in THF (100 mL). After stirring for 10 minutes n-butyl lithium (16 mL of 2.5 M in hexane) was added and the mixture was aged for an additional 10 minutes. At this time iodomethane (2.74 mL, 44 mmol) in THF (4 mL) was added dropwise and the mixture aged 1 hour while slowly warming to room temperature. Work-up was achieved by quenching at 0° C. with 1N HCl, extracting with ether, washing the ether with aqueous NaHCO3, brine, and drying with MgSO4. Removal of the solvent yielded benzyl 3-oxopentanoate. was added the mixture aged 1 hour by quenching at 0° C. with 1N HCl extracting with ether washing the ether with aqueous NaHCO3, brine drying with MgSO4 Removal of the solvent

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

Procedure: A solution of benzyl propionylacetate (157 g, 0.758 mol), 2,4-difluorobenzaldehyde (107.65 g, 0.758 mol), and piperidinium acetate (5.49 g, 38 mmol) in benzene (1 L) were stirred at room temperature for 96 h. The mixture was washed with water (2×100 mL), dried (magnesium sulfate) and the solvent evaporated under reduced pressure to yield the product as a pale yellow syrup (251.2 g) which was used in the next step without further purification. The mixture was washed with water (2×100 mL) dried (magnesium sulfate) the solvent evaporated under reduced pressure

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

Procedure: A solution of benzyl propionylacetate (157 g, 0.758 mol), 2,4-difluorobenzaldehyde (107.65 g, 0.758 mol), and piperidinium acetate (5.49 g, 38 mmol) in benzene (1 L) were stirred at room temperature for 96 h. The mixture was washed with water (2×100 mL), dried (magnesium sulfate) and the solvent evaporated under reduced pressure to yield the product as a pale yellow syrup (251.2 g) which was used in the next step without further purification. The mixture was washed with water (2×100 mL) dried (magnesium sulfate) the solvent evaporated under reduced pressure

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: A solution of benzyl propionylacetate (36.3 g, 176 mmol), 3,4-difluorobenzaldehyde (25.0 g, 176 mmol), piperidine (0.86 mL, 9.0 mmol) and acetic acid (0.49 mL, 9.0 mmol) was refluxed with removal of water using a Dean-Stark apparatus for 5 h. The solvent was removed in vacuo and the residue was dissolved in EtOAc. The reaction mixture was washed with water (100 mL), followed by brine (100 mL) and dried over anhydrous Na2SO4. The solvent was evaporated, giving a pale yellow syrup (60.2 g). The product was used in the next step without further purification. The solvent was removed in vacuo the residue was dissolved in EtOAc The reaction mixture was washed with water (100 mL) dried over anhydrous Na2SO4 The solvent was evaporated