摘要:
The present invention relates to a process for preparation of 5-bromo-1,2,3-trichlorobenzene of formula (I) in simple, economical manner with high yield. The 5-bromo-1,2,3-trichlorobenzene of formula (I) is used in preparation of 1-(3,4,5-trichloro-phenyl)-2,2,2-trifluoro-ethanone which is a key intermediate of isoxazoline derivatives. (I)
摘要:
Disclosed is a method of making 1,2,4-trichlorobenzene. Dichlorobenzene containing less than an isomeric amount of meta-dichlorobenzene is isomerized to produce an isomeric mixture of dichlorobenzenes substantially rich in meta-dichlorobenzene. The isomeric mixture of dichlorobenzenes is chlorinated with gaseous chlorine to produce 1,2,4-trichlorobenzene and unreacted dichlorobenzenes. The mixture of 1,2,4-trichlorobenzene and unreacted dichlorobenzenes is separated by distillation and the unreacted dichlorobenzenes are recycled to the isomerizer.