反応 #2254188

反応方程式

ethylcyanoformate

Ethylmagnesium chloride

3-(5-bromo-4-methyl-thiophen-2-yl)-5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazole

→

5-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophene-2-carboxylic acid ethyl ester

収率 56.8%

溶媒

THF

THF

反応条件

後処理

1. 1
   workup.WAITAfter 40 minutes
2. 2
   その他the reaction is quenched with a saturated aqueous solution of NH4Cl in water
3. 3
   抽出The mixture is extracted three times with MTBE
4. 4
   乾燥dried over Na2SO4
5. 5
   濃縮concentrated in vacuo
6. 6
   その他The crude product is purified on a semi-preparative HPLC

実験手順

Ethylmagnesium chloride (10.9 ml, 2M in THF) is added over 30 minutes to a solution of 3-(5-bromo-4-methyl-thiophen-2-yl)-5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazole (10.0 g, Example 2, step D) in THF (15 ml) at 0° C. After 1 hour at room temperature, a solution of ethylcyanoformate (2.81 g) in THF (15 ml) is added to the reaction mixture. After 40 minutes, the reaction is quenched with a saturated aqueous solution of NH4Cl in water. The mixture is extracted three times with MTBE. The organic phases are combined, dried over Na2SO4 and concentrated in vacuo. The crude product is purified on a semi-preparative HPLC to yield 5-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophene-2-carboxylic acid ethyl ester (5.6 g) as a yellowish oil.

出典