To produce 3-bromo-2-(substituted phenyl)-1-propene useful as a synthetic intermediate for a pharmaceutical or agrochemical at high seleetivity and yield by using 2-phenyl-1,2,3-tribromopropane as a raw material.

This 3-bromo-2-(substituted phenyl)-1-propene of formula II is produced by catalytic hydrogenation of 2-phenyl-1,2,3-tribromopropane of formula I [R is a halogen, cyano, nitro or trifluoromethyl; (n) is 1,2]. This reaction is preferably carried out using a catalyst such as a Raney nickel or Vd/C. A hydrogen pressure is preferably about 1-30atm. Further, the reaction is preferably carried out in the presence of a base. Furthermore, e.g. a herbicide of formula III is produced from a compound of formula II.