3-hydroxy-4,4-dimethylpyrrolidin-2-one

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

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

Procedure: tert-Butyldimethylsilyl trifluoromethanesulfonate (0.810 ml, 3.45 mmol) was added to a mixture of 3-hydroxy-4,4-dimethyl-2-pyrrolidinone (405 mg, 3.1 mmol) and triethylamine (0.481 mmol, 3.45 mmol) in anhydrous dichloromethane (20 mL) at 0° C. under nitrogen. The reaction mixture was allowed to warm to room temperature, and was stirred for 18 h. A catalytic portion of 4-(dimethylamino)pyridine was added, and the mixture was stirred for 5 h. 1,8-Diazabicyclo[5.4.0]undec-7-ene (0.470 mL, 3.13 mmol) and tert-butyldimethylsilyl trifluoromethanesulfonate (0.360 ml, 1.61 mmol) were then added. After an additional 16 h, a third portion of tert-butyldimethylsilyl trifluoromethanesulfonate was added (0.360 ml, 1.61 mmol). The reaction mixture was then stirred for a further 7.5 h, before being diluted with dichloromethane (75 mL). It was then washed with two 30 mL portions of 1N hydrochloric acid. The washes were combined and back-extracted with dichloromethane (30 mL). The dichloromethane layers were then combined, washed with saturated aqueous sodium chloride (20 mL), dried over magnesium sulfate, and concentrated to a tan oil. Further purification of this oil by column chromatography on silica gel, eluting with a gradient of 20-50% ethyl acetate in hexane afforded 3-{[tert-butyl(dimethyl)silyl]oxy}-4,4-dimethyl-2-pyrrolidinone as a colorless oil that crystallized upon standing (362 mg, 48%). 1H NMR (300 MHz, DMSO-d6) δ 7.63 (br s, 1H), 3.85 (s, 1H), 2.96-2.84 (m, 2H), 1.08 (s, 3H), 0.92 (s, 3H), 0.91 (s, 9H), 0.13 (s, 3H), 0.10 (s, 3H). ES-LCMS m/z 244 (M+H). the mixture was stirred for 5 h After an additional 16 h The reaction mixture was then stirred for a further 7.5 h It was then washed with two 30 mL portions of 1N hydrochloric acid back-extracted with dichloromethane (30 mL) washed with saturated aqueous sodium chloride (20 mL) dried over magnesium sulfate concentrated to a tan oil Further purification of this oil by column chromatography on silica gel eluting with a gradient of 20-50% ethyl acetate in hexane

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

Procedure: tert-Butyldimethylsilyl trifluoromethanesulfonate (0.810 ml, 3.45 mmol) was added to a mixture of 3-hydroxy-4,4-dimethyl-2-pyrrolidinone (405 mg, 3.1 mmol) and triethylamine (0.481 mmol, 3.45 mmol) in anhydrous dichloromethane (20 mL) at 0° C. under nitrogen. The reaction mixture was allowed to warm to room temperature, and was stirred for 18 h. A catalytic portion of 4-(dimethylamino)pyridine was added, and the mixture was stirred for 5 h. 1,8-Diazabicyclo[5.4.0]undec-7-ene (0.470 mL, 3.13 mmol) and tert-butyldimethylsilyl trifluoromethanesulfonate (0.360 ml, 1.61 mmol) were then added. After an additional 16 h, a third portion of tert-butyldimethylsilyl trifluoromethanesulfonate was added (0.360 ml, 1.61 mmol). The reaction mixture was then stirred for a further 7.5 h, before being diluted with dichloromethane (75 mL). It was then washed with two 30 mL portions of 1N hydrochloric acid. The washes were combined and back-extracted with dichloromethane (30 mL). The dichloromethane layers were then combined, washed with saturated aqueous sodium chloride (20 mL), dried over magnesium sulfate, and concentrated to a tan oil. Further purification of this oil by column chromatography on silica gel, eluting with a gradient of 20-50% ethyl acetate in hexane afforded 3-{[tert-butyl(dimethyl)silyl]oxy}-4,4-dimethyl-2-pyrrolidinone as a colorless oil that crystallized upon standing (362 mg, 48%). 1H NMR (300 MHz, DMSO-d6) δ 7.63 (br s, 1H), 3.85 (s, 1H), 2.96-2.84 (m, 2H), 1.08 (s, 3H), 0.92 (s, 3H), 0.91 (s, 9H), 0.13 (s, 3H), 0.10 (s, 3H). ES-LCMS m/z 244 (M+H). the mixture was stirred for 5 h After an additional 16 h The reaction mixture was then stirred for a further 7.5 h It was then washed with two 30 mL portions of 1N hydrochloric acid back-extracted with dichloromethane (30 mL) washed with saturated aqueous sodium chloride (20 mL) dried over magnesium sulfate concentrated to a tan oil Further purification of this oil by column chromatography on silica gel eluting with a gradient of 20-50% ethyl acetate in hexane

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

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

Procedure: tert-Butyldimethylsilyl trifluoromethanesulfonate (0.810 ml, 3.45 mmol) was added to a mixture of 3-hydroxy-4,4-dimethyl-2-pyrrolidinone (405 mg, 3.1 mmol) and triethylamine (0.481 mmol, 3.45 mmol) in anhydrous dichloromethane (20 mL) at 0° C. under nitrogen. The reaction mixture was allowed to warm to room temperature, and was stirred for 18 h. A catalytic portion of 4-(dimethylamino)pyridine was added, and the mixture was stirred for 5 h. 1,8-Diazabicyclo[5.4.0]undec-7-ene (0.470 mL, 3.13 mmol) and tert-butyldimethylsilyl trifluoromethanesulfonate (0.360 ml, 1.61 mmol) were then added. After an additional 16 h, a third portion of tert-butyldimethylsilyl trifluoromethanesulfonate was added (0.360 ml, 1.61 mmol). The reaction mixture was then stirred for a further 7.5 h, before being diluted with dichloromethane (75 mL). It was then washed with two 30 mL portions of 1N hydrochloric acid. The washes were combined and back-extracted with dichloromethane (30 mL). The dichloromethane layers were then combined, washed with saturated aqueous sodium chloride (20 mL), dried over magnesium sulfate, and concentrated to a tan oil. Further purification of this oil by column chromatography on silica gel, eluting with a gradient of 20-50% ethyl acetate in hexane afforded 3-{[tert-butyl(dimethyl)silyl]oxy}-4,4-dimethyl-2-pyrrolidinone as a colorless oil that crystallized upon standing (362 mg, 48%). 1H NMR (300 MHz, DMSO-d6) δ 7.63 (br s, 1H), 3.85 (s, 1H), 2.96-2.84 (m, 2H), 1.08 (s, 3H), 0.92 (s, 3H), 0.91 (s, 9H), 0.13 (s, 3H), 0.10 (s, 3H). ES-LCMS m/z 244 (M+H). the mixture was stirred for 5 h After an additional 16 h The reaction mixture was then stirred for a further 7.5 h It was then washed with two 30 mL portions of 1N hydrochloric acid back-extracted with dichloromethane (30 mL) washed with saturated aqueous sodium chloride (20 mL) dried over magnesium sulfate concentrated to a tan oil Further purification of this oil by column chromatography on silica gel eluting with a gradient of 20-50% ethyl acetate in hexane