Reacción #45614

Ecuación de reacción

tributyl(1-ethoxyvinyl)tin

6-Bromo-2-cyclopropyl-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrile

→

crude product

Rendimiento 108.5%

2-Cyclopropyl-6-[1-(ethoxy)ethenyl]-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrile

Rendimiento 108.5%

Disolventes

toluene

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturaby heating
2. 2
   Temperaturaunder reflux for 17 hours under nitrogen atmosphere
3. 3
   OtroThe reaction liquid
4. 4
   Temperaturawas cooled
5. 5
   Otrothe insoluble matter was separated by filtration through Celite
6. 6
   Concentraciónthe solvent was concentrated under reduced pressure
7. 7
   Otroby removing tin-
8. 8
   Lavadoby elution with a mixed solvent of n-hexane/ethyl acetate (7:1

Procedimiento

6-Bromo-2-cyclopropyl-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrile (I-77) (8.88 g, 30.08 mmol) was dissolved in toluene (130 ml), then tributyl(1-ethoxyvinyl)tin (11.2 ml, 33.09 mmol) and 2,6-di-tert-butylcresol (66 mg, 0.30 mmol) and bis(triphenylphosphine)palladium(II) dichloride (1.06 g, 1.50 mmol) were added, followed by heating under reflux for 17 hours under nitrogen atmosphere. The reaction liquid was cooled, the insoluble matter was separated by filtration through Celite, the solvent was concentrated under reduced pressure. The resulting residue was subjected to silica gel column chromatography, followed by removing tin-derived side products with n-hexane and by elution with a mixed solvent of n-hexane/ethyl acetate (7:1, v/v) to obtain the a crude product (9.34 g, quant.) as a yellow white solid.

Fuente