| 摘要 |
The invention comprises a process for the action of chlorine on bistrichloromethyl orthohalobenzenes to give nuclear halogenated monotrichloromethylbenzenes; and the product 1-trichloromethyl - 3 - fluoro - 4 - chlorobenzene. In examples, 1 : 4-bis-trichloromethyl-2-chlorobenzene, 1 : 3 - bis - trichloromethyl - 4 - chlorobenzene, 1 : 4 - bis - trichloromethyl 2 : 5 - dichlorobenzene and 1 : 4-bistrichloromethyl-2-fluorobenzene are treated with chlorine to give the corresponding 1 - trichloromethyl 3 : 4 - dichlor -, 2 : 4 : 5 - trichloro - and 3 - fluoro - 4-chlorobenzene, the chlorine wholly replacing one trichloromethyl group and also nuclear bromine to give CCl4 as by-product. The process may be combined with the side-chain chlorination of dimethylbenzenes containing nuclear halogen, in examples, the chlorination of 1 : 4-dimethyl-2-chlorobenzene and 1 : 4-dimethyl - 2 - homobenzene direct to 1 - chloromethyl - 3 : 4 - dichlorobenzene. The products may be hydrolysed to the corresponding acid chlorides and acids, e.g. 3 : 4-dichlorobenzoyl chloride, 3 : 4-dichlorobenzoic acid, and 2 : 4 : 5-trichlorbenzoic acid. Other starting-materials specified include 1 : 3-bistrichloromethyl-4 : 6-dichlorobenzene. |
