Reacción #2254188

Ecuación de reacción

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

Rendimiento 56.8%

Disolventes

THF

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.WAITAfter 40 minutes
2. 2
   Otrothe reaction is quenched with a saturated aqueous solution of NH4Cl in water
3. 3
   ExtracciónThe mixture is extracted three times with MTBE
4. 4
   Secadodried over Na2SO4
5. 5
   Concentraciónconcentrated in vacuo
6. 6
   OtroThe crude product is purified on a semi-preparative HPLC

Procedimiento

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.

Fuente