Methyl iodide → HCID 10487759、化合物

反応式

[OH:1][C:2]1[C:6]([CH3:7])=[C:5]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[O:4][N:3]=1.[C:13]([O-])([O-])=O.[K+].[K+].CI>C(O)C>[CH3:13][O:1][C:2]1[C:6]([CH3:7])=[C:5]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[O:4][N:3]=1

参加物

反応条件

温度: 40 °C

実験手順

A mixture of ethyl 3-hydroxy-4-methylisoxazole-5-carboxylate (2.0 g, 11.7 mmol) and K2CO3 (4.0 g, 29 mmol) in ethanol (50 mL) was heated at 40° C. for a total of 26 h. Methyl iodide (0.8 mL, 13 mmol) was added after 1 h and an additional 3 times during the next 25 h. The solution was filtered and reduced in vacuo (according to 1H NMR, a 1:1 mixture of the title compound and ethyl 3-methoxy-4-methylisoxazole-5-carboxylate was obtained). Flash chromatography (silica gel, eluent: dichloromethane/diethyl ether=9:1 then 1:1) gave ethyl 3-Methoxy-4-methylisoxazole-5-carboxylate as a yellow oil (0.40, 18%) and title compound (0.45 g, 21%). A small sample of the latter was recrystallized (EtOAc/heptane) to give colorless crystals: mp 64-65° C. Crude title compound was used in the next step without further purification.