Methyl iodide → tert-Butyl 3,3-dimethyl-4-oxopiperidine-1-carboxylate

反応式

[C:1]([O:5][C:6]([N:8]1[CH2:13]CC(=O)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[H-].[Na+].[CH3:17]I.[O:19]1[CH2:23][CH2:22][CH2:21]C1>>[C:1]([O:5][C:6]([N:8]1[CH2:9][CH2:10][C:23](=[O:19])[C:22]([CH3:21])([CH3:17])[CH2:13]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

参加物

反応物 4

HCID 6328Methyl iodide

HCID 8028Tetrahydrofuran

HCID 24758Sodium hydride

HCID 735900tert-Butyl 4-oxopiperidine-1-carboxylate

生成物 1

HCID 22278899tert-Butyl 3,3-dimethyl-4-oxopiperidine-1-carboxylate収率 32%

反応条件

温度: 0 °C

実験手順

4-Oxo-piperidine-1-carboxylic acid tert-butyl ester (5 g, 25 mmol) was dissolved in tetrahydrofuran (100 mL) and the resulting solution was cooled to 0° C. Sodium hydride (60% in mineral oil, 2.10 g, 53 mmol) was added to the cooled solution in a single portion, and the resulting cloudy mixture was allowed to stir 10 min. Methyl iodide was subsequently added and the mixture was allowed to warm to room temperature over several hours. Stirring continued over night (12 h). The light orange mixture was concentrated under reduced pressure. The residue was partitioned between ether and water. The aqueous phase was back-extracted with additional ether. The combined extracts were washed with water and brine, dried over sodium sulfate, filtered and concentrated to a pale yellow solid. The solid was triturated with 4% ethyl acetate in hexanes (50 mL) to afford 3,3-dimethyl-4-oxo-piperidine-1-carboxylic acid tert-butyl ester as a cream-colored solid (1.8 g, 32%).