4519-46-4

Methyl α-bromoacrylate can undergo radical copolymerization with vinyl triacetoxysilane (VTAS) in the presence of azobisisobutyronitrile as the initiator. Dibromocyclopropanation of methyl α-bromoacrylate can yield methyl 1,1,2-tribromocyclopropanecarboxylate. It may be reduced with zinc dust and deuterium oxide to synthesize. Methyl acrylate-α-d with a high isotopic purity. These may undergo conjugate addition with methoxide, thiolates, oxime anions, hydrazones and EtZnCl to afford ester enolates.

Example-1 Preparation of α-bromo methyl acrylate: methyl acrylate (100 g) was mixed with dichloromethane (300 mL) and cooled to 0-5°C. Bromine (60 mL) was slowly added dropwise at 0-5°C and the dropwise process lasted for 1 hour. After completion of the reaction, the reaction mixture was stirred at 25-30 °C for 4-5 hours. Subsequently, 10% NaHCO3 solution (100 mL) was added, stirred for 30 minutes and left to stratify. Sodium carbonate (250 g) and triethylamine (160 mL) were added to the dichloromethane layer and stirred at 25-30 °C for 1 hour. The mixture was kept at the same temperature for 2 hours and then filtered. To the filtrate, 20% HCl solution (100 mL) was added, stirred for 30 minutes and left to stratify. The organic layer was washed with 20% HCl solution (100 mL). Finally, the solvent was removed by distillation under reduced pressure at less than 30 °C to give α-bromoacrylic acid methyl ester. Yield: 140 g.

[1] Journal of Organic Chemistry, 2004, vol. 69, # 24, p. 8561 - 8563
[2] Patent: WO2012/25936, 2012, A2. Location in patent: Page/Page column 8-9
[3] Patent: US2013/184469, 2013, A1. Location in patent: Paragraph 0027
[4] Patent: US2016/287726, 2016, A1. Location in patent: Paragraph 0079; 0080