3-Bromo-2-methylpropene

mol of 4-bromotoluene was added to the reaction vessel, the temperature was raised to 65 °C, and 7 mol of 25% oxalic acid solution was added. After the addition was complete, 6 mol of methylallyl bromide was added. After the addition was complete, the mixture was refluxed for 80 min, and then distilled under reduced pressure at 15 kPa. The fraction at 55 °C was collected. The collected distillate was washed with 35% potassium bicarbonate solution, allowed to stand and separate into layers, and the oil layer was removed. The oil layer was washed with 20% potassium bromide solution, 80% triethylamine solution, and 90% propionitrile solution. The oil layer was then dehydrated with a solid phosphorus pentoxide dehydrating agent to obtain 562.55 g of the product 3-bromo-2-methylpropene, with a yield of 93%.

clear colorless to yellow liquid

3-Bromo-2-methylpropene may be used:

• in the synthesis of alkenyl imines
• in the synthesis of 2-methylpropenyl (“methallyl”) complex, Cp*Os(η³-allyl)Br₂
• in a study of chiral phase transfer alkylation leading to (S)-α-alkylcysteines

3-Bromo-2-methylpropene is used as a general reagent for various organic reactions and primarily for amino acid synthesis and asymmetric amino acid synthesis.

Rotational isomerism in 3-bromo-2-methylpropene has been studied by IR spectroscopy.