| 摘要 |
NEW MATERIAL:The compound of formula I and formula II. USE:The compound of formula II is useful as an intermediate raw material for pharmaceuticals, agricultural chemicals, liquid crystals, etc., and the compound of formula I is useful as a precursor of the compound of formula II. PREPARATION:2,5-Bis(trifluoromethyl)nitrobenzene of formula III is subjected to site-selective halogen-exchange reaction with a metal chloride (e.g. aluminum chloride) at <=70 deg.C optionally in an inert solvent (e.g. methylene chloride) to obtain the compound of formula I. The product is hydrolyzed in the presence of a Lewis acid catalyst (e.g. ferric chloride) at 80-250 deg.C to obtain the compound of formula II free from position isomers of the nitro group.
|
