| abstract |
PURPOSE: To obtain the subject compound widely useful as intermediates for pharmaceuticals and agricultural chemicals in high purity by treating a crude reaction product of the subject compound containing dimer as an impurity with activated carbon in a solvent, thereby efficiently removing the impurity. n CONSTITUTION: A compound of formula III or formula IV or their salt containing a compound of formula I or formula II (R is H or lower alkyl; X is halogen; Y is O, CO or NHCO; n and m are 1-6) or their salt is treated with activated carbon in a solvent such as lower alcohol or alkyl halide to remove the compound of formula I or formula II or their salt. When the raw material is the compound of formula III or formula IV, water or a mixture of water and a water-soluble organic solvent can be used as the solvent. The activated carbon is preferably powdery charcoal and its amount is 0.1-20wt.%, preferably 0.5-10wt.% based on the substrate. n COPYRIGHT: (C)1992,JPO&Japio |