Reaction #309152

Reaction equation

sodium bicarbonate

3-chloro-2-chloromethyl-1-propene

ethyl (4-bromophenyl)acetate

LHMDS

→

ethyl 2-(4-bromophenyl)-4-(chloromethyl)pent-4-enoate

Ethyl 2-(4-bromophenyl)-4-(chloromethyl)pent-4-enoate

Solvents

THF

THF

Conditions

Workup

1. 1
   Temperatureto slowly warm from −78° C. to rt over 15 hours
2. 2
   Extractionextracted with EtOAc
3. 3
   Dryingdried over sodium sulfate
4. 4
   Filtrationfiltered
5. 5
   Concentrationconcentrated
6. 6
   OtherThe crude residue was purified by column chromatography
7. 7
   Washeluting with 1-20% EtOAc/Hexane
8. 8
   Otherthe solvent removed in vacuo

Procedure

To a solution of ethyl (4-bromophenyl)acetate (143 g, 588 mmol) in THF (800 mL) was added LHMDS (1.13 eq in THF) at −78° C. After 30 minutes, the reaction mixture was added to a solution of 3-chloro-2-chloromethyl-1-propene (147 g, 1180 mmol) in THF (500 mL) at −78° C. via cannula. The reaction was allowed to slowly warm from −78° C. to rt over 15 hours. The reaction mixture was poured into sodium bicarbonate, extracted with EtOAc, dried over sodium sulfate, filtered and concentrated. The crude residue was purified by column chromatography eluting with 1-20% EtOAc/Hexane. The appropriate fractions were combined and the solvent removed in vacuo to give ethyl 2-(4-bromophenyl)-4-(chloromethyl)pent-4-enoate (1-1) as a clear oil. MS (M+H)+: 332.

Source