Reacción #1269824

Ecuación de reacción

diisopropyl ether

ethyl bromodifluoroacetate THF

ethyl bromodifluoroacetate

propionaldehyde THF

propionaldehyde

→

2,2-difluoro-3-hydroxypentanoic acid ethyl ester

Rendimiento 89.0%

Disolventes

THF

water

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.STIRRINGby stirring at room temperature for 30 minutes
2. 2
   Otroa two-layer separation
3. 3
   LavadoThe obtained organic layer was washed with diluted hydrochloric acid and water
4. 4
   Otroby removing water by magnesium sulfate
5. 5
   Filtracióna filtration
6. 6
   workup.DISTILLATIONdistilling diisopropyl ether out

Procedimiento

A 500 mL reactor was charged with 24.2 g (370 mmol/1.5 equivalents) of an activated metal zinc and 300 mL of THF (dehydrated), and thereto an ethyl bromodifluoroacetate/THF solution [51.47 g (253.6 mmol/1.0 equivalent) of ethyl bromodifluoroacetate and 80 mL of THF (dehydrated)] was added dropwise. After the dropping, stirring was conducted at room temperature for 20 minutes. Then, a propionaldehyde/THF solution [14.80 g (254.8 mmol/1.0 equivalent) of propionaldehyde and 80 mL of THF (dehydrated)] was added, followed by stirring at room temperature for 30 minutes. Then, water and diisopropyl ether were added to conduct a two-layer separation. The obtained organic layer was washed with diluted hydrochloric acid and water, followed by removing water by magnesium sulfate, conducting a filtration, and distilling diisopropyl ether out, thereby obtaining 41.2 g of the target 2,2-difluoro-3-hydroxypentanoic acid ethyl ester. Upon this, yield was 89%.

Fuente