The coupling of 1-bromo-3,4-(methylenedioxy)benzene with β-methallyl alcohol was catalyzed by Pd(OAc)2 in combination with P(t-Bu)3.
Synthesis
NBS (1.87 g, 10.50 mmol, 1.05 equiv.), HPLC-grade acetonitrile and benzo[d][1,3]dioxole (10 mmol) were placed into a flask and stirred until completely homogeneous. The solution was pumped through the Corning G1 photoreactor at the desired flow rate. The reaction mixture was collected from the reactor and combined with the two separate streams of toluene and water into a 10-mL Vapourtec static mixer coil; then, the mixture was pumped into a Zaiput liquid-liquid membrane separator, the organic phase was collected and passed twice more through the Zaiput membrane separator. The organic phase was evaporated under reduced pressure, providing the corresponding brominated product 4-Bromo-1,2-(methylenedioxy)benzene.