2-phenylpropanoyl chloride

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: A mixture of (4S)-(-)-4-benzyl-2-oxazolidinone (3.903 g, 22.0 mmol) in THF (23 ml) is cooled at -78° and butyl lithium (1.6M in hexane, 14.7 ml, 23.5 mmol) is added. The mixture is stirred for 50 min and then the portion of 2-phenylpropionic acid chloride (XL) from above, in THF (8 ml) is added dropwise to the mixture. The mixture is stirred for 1 hr at -78° and then allowed to warm to 20-25°. Saturated aqueous sodium bicarbonate solution (100 ml) is added and the phases separated. The aqueous phase is washed with ether and the combined organic phases are then washed several times with saturated aqueous sodium bicarbonate followed by a saline wash. The organic phase is dried over magnesium sulfate and concentrated. The resulting diastereomers are separated on silica gel eluting with ethyl acetate/hexane (7/93) followed by ethyl acetate/hexane (12/88). The appropriate fractions are pooled and concentrated to give (4S)-4-(phenylmethyl)-3-(2-phenylpropionyl)-2-oxazolidinone (XLI, Isomer I, less polar isomer), NMR (CDCl3) 1.55, 2.79, 3.35, 4.09, 4.58, 5.12 and 7.30 δ; and (4S)-4-(phenylmethyl)-3-(2-phenylpropionyl)-2-oxazolidinone (XLII, Isomer II, more polar isomer), NMR (CDCl3) δ 1.52, 2.58, 3.09, 4.08, 4.19, 4.75, 5.11, 6.95 and 7.31 δ. is cooled at -78° The mixture is stirred for 1 hr at -78° to warm to 20-25° the phases separated The aqueous phase is washed with ether the combined organic phases are then washed several times with saturated aqueous sodium bicarbonate wash The organic phase is dried over magnesium sulfate concentrated The resulting diastereomers are separated on silica gel eluting with ethyl acetate/hexane (7/93) concentrated

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: (±)-2-Phenylpropionic acid in the amount of 7.50 g (50 mmol) and 7.14 g (60 mmol) of thionyl chloride were heated for 1 hour under reflux in carbon tetrachloride. The solvent and unaltered thionyl chloride were evaporated under reduced pressure to give (±)-2-phenylpropionic acid chloride as a pale yellow oil. To the oil were added 30 ml of benzene, 7.30 g (52.5 mmol) of p-nitrophenol and 4.75 g (60.0 mmol) of pyridine were added, and the mixture was stirred at room temperature for 2 hours. The reaction mixture was diluted with 10 ml of aqueous 10% hydrochloric acid, extracted with ethyl acetate, followed by solvent evaporation from the organic layer, to obtain 13.9 g of a pale yellow solid. Recrystallization of the solid from ethanol gave 10.4 g (38.4 mmol, yield 77%) of (±)-p-nitrophenyl 2-phenylpropionate as colorless crystals. The solvent and unaltered thionyl chloride were evaporated under reduced pressure

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

Procedure: (±)-2-Phenylpropionic acid in the amount of 7.50 g (50 mmol) and 7.14 g (60 mmol) of thionyl chloride were heated for 1 hour under reflux in carbon tetrachloride. The solvent and unaltered thionyl chloride were evaporated under reduced pressure to give (±)-2-phenylpropionic acid chloride as a pale yellow oil. To the oil were added 30 ml of benzene, 7.30 g (52.5 mmol) of p-nitrophenol and 4.75 g (60.0 mmol) of pyridine were added, and the mixture was stirred at room temperature for 2 hours. The reaction mixture was diluted with 10 ml of aqueous 10% hydrochloric acid, extracted with ethyl acetate, followed by solvent evaporation from the organic layer, to obtain 13.9 g of a pale yellow solid. Recrystallization of the solid from ethanol gave 10.4 g (38.4 mmol, yield 77%) of (±)-p-nitrophenyl 2-phenylpropionate as colorless crystals. The solvent and unaltered thionyl chloride were evaporated under reduced pressure

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

Procedure: To a stirred solution of 2-phenylpropionic acid (0.36 mL; 2.6 mmol) and a catalytic amount of dry dimethylformamide (ca. 10 μL) in 3.0 mL of dry methylene chloride under nitrogen at room temperature was added oxalyl chloride (0.34 mL; 3.9 mmol) dropwise. After 30 minutes, the mixture was concentrated in vacuo and used immediately for Step 2. the mixture was concentrated in vacuo