4-(4-methoxyphenyl)butanoyl chloride

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

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

Procedure: 4-(4-Methoxyphenyl)butyric acid (2.0 g, 10.3 mmol) was treated with thionyl chloride (20 mL). The reaction was stirred at rt for 3 h, heated at 65° C. overnight and then concentrated under reduced pressure to give 4-(4-methoxyphenyl)butyryl chloride (2.3 g) as a yellow oil which was used without farther purification. IR (NaCl): 1795, 1510, 1244 cm-1. heated at 65° C. overnight concentrated under reduced pressure

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

Procedure: L-prolinal diethyl acetal hydrochloride is dissolved, together with 4-(p-methoxyphenyl)butyryl chloride (686 mg, 4.02 mmol) prepared in the same manner as described in Example 5, in methylene chloride (12 ml) and triethylamine (1.7 ml, 12.2 mmol) is added dropwise thereto under ice-cooling and agitation. After the dropwise addition, stirring is further continued for 30 minutes under cooling, and then for one hour at room temperature. Ether (40 ml) is added to the reaction mixture, and the ethereal layer is separated, washed with a saturated aqueous solution of sodium hydrogen carbonate and a saturated aqueous solution of edible salt, dried over sodium sulfate and filtered. The filtrate is concentrated to dryness under reduced pressure. The residue is purified by column chromatography on silica gel (n-hexane-ethyl acetate, 2:1) to give 805 mg (58%) of the title compound as a pale yellow syrup. prepared in the same manner under ice-cooling After the dropwise addition under cooling for one hour at room temperature the ethereal layer is separated washed with a saturated aqueous solution of sodium hydrogen carbonate a saturated aqueous solution of edible salt, dried over sodium sulfate filtered The filtrate is concentrated to dryness under reduced pressure The residue is purified by column chromatography on silica gel (n-hexane-ethyl acetate, 2:1)

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

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

Procedure: 4-(4-Methoxyphenyl)butyric acid (2.0 g, 10.3 mmol) was treated with thionyl chloride (20 mL). The reaction was stirred at rt for 3 h, heated at 65° C. overnight and then concentrated under reduced pressure to give 4-(4-methoxyphenyl)butyryl chloride (2.3 g) as a yellow oil which was used without farther purification. IR (NaCl): 1795, 1510, 1244 cm-1. heated at 65° C. overnight concentrated under reduced pressure

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

Procedure: L-prolinal diethyl acetal hydrochloride is dissolved, together with 4-(p-methoxyphenyl)butyryl chloride (686 mg, 4.02 mmol) prepared in the same manner as described in Example 5, in methylene chloride (12 ml) and triethylamine (1.7 ml, 12.2 mmol) is added dropwise thereto under ice-cooling and agitation. After the dropwise addition, stirring is further continued for 30 minutes under cooling, and then for one hour at room temperature. Ether (40 ml) is added to the reaction mixture, and the ethereal layer is separated, washed with a saturated aqueous solution of sodium hydrogen carbonate and a saturated aqueous solution of edible salt, dried over sodium sulfate and filtered. The filtrate is concentrated to dryness under reduced pressure. The residue is purified by column chromatography on silica gel (n-hexane-ethyl acetate, 2:1) to give 805 mg (58%) of the title compound as a pale yellow syrup. prepared in the same manner under ice-cooling After the dropwise addition under cooling for one hour at room temperature the ethereal layer is separated washed with a saturated aqueous solution of sodium hydrogen carbonate a saturated aqueous solution of edible salt, dried over sodium sulfate filtered The filtrate is concentrated to dryness under reduced pressure The residue is purified by column chromatography on silica gel (n-hexane-ethyl acetate, 2:1)