تفاعل #2254188

معادلة التفاعل

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

المردود 56.8%

المذيبات

THF

THF

ظروف التفاعل

المعالجة

1. 1
   workup.WAITAfter 40 minutes
2. 2
   أخرىthe reaction is quenched with a saturated aqueous solution of NH4Cl in water
3. 3
   استخلاصThe mixture is extracted three times with MTBE
4. 4
   تجفيفdried over Na2SO4
5. 5
   تركيزconcentrated in vacuo
6. 6
   أخرىThe crude product is purified on a semi-preparative HPLC

الإجراء التجريبي

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.

المصدر