Reacción #366339

Ecuación de reacción

(1R)-1-[2-(2,4-Difluorophenyl)-2-oxiranyl]ethanol

3,5-dinitrobenzoyl chloride

→

[(1R)-1-[(2R)-2-(2,4-difluorophenyl)-2-oxiranyl]ethyl] 3,5-dinitrobenzoate

Rendimiento 46.3%

Disolventes

methylene chloride

trimethylamine

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONwas added dropwise at ice-bath temperature
2. 2
   Lavadoit was washed with water (150 ml) and 5% sodium bicarbonate aqueous solution successively
3. 3
   Secadodried over magnesium sulfate
4. 4
   Concentraciónconcentrated under reduced pressure
5. 5
   FiltraciónThe precipitated crystals were filtrated
6. 6
   Lavadowashed with methylene chloride
7. 7
   workup.DISTILLATIONdistilled off under reduced pressure
8. 8
   workup.ADDITIONEthyl acetate (25 ml) and methanol (300 ml) were added to the residue
9. 9
   Temperaturathe mixture was cooled in an ice bath
10. 10
    FiltraciónThe precipitated crystals were collected by filtration
11. 11
    Otrorecrystallized from a mixture of ethyl acetate (25 ml) and methanol (250 ml)

Procedimiento

(1R)-1-[2-(2,4-Difluorophenyl)-2-oxiranyl]ethanol (31.5 g) and 3,5-dinitrobenzoyl chloride (40 g) were dissolved in methylene chloride (500 ml), to which trimethylamine (24.1 ml) was added dropwise at ice-bath temperature. After the mixture was stirred at room temperature for 3.5 hours, it was washed with water (150 ml) and 5% sodium bicarbonate aqueous solution successively, dried over magnesium sulfate and concentrated under reduced pressure. The precipitated crystals were filtrated and washed with methylene chloride. The mother liquor and the washings were combined and distilled off under reduced pressure. Ethyl acetate (25 ml) and methanol (300 ml) were added to the residue, and the mixture was cooled in an ice bath. The precipitated crystals were collected by filtration and recrystallized from a mixture of ethyl acetate (25 ml) and methanol (250 ml) to give [(1R)-1-[(2R)-2-(2,4-difluorophenyl)-2-oxiranyl]ethyl] 3,5-dinitrobenzoate (28.7 g) as colorless needles.

Fuente