| 摘要 |
The invention relates to a process for preparing chlorobenzoxazoles of the formula (I),in which R1, R2 and R4 are as defined in claim 1 andin case (a) R3=H, halogen, CN, NO2, C1-C5-alkyl, C1-C5-alkoxy, aryl or aryloxy, where each of the 4 lastmentioned radicals is unsubstituted or substituted, orin case (b) R3=chlorine,which comprises reacting benzoxazoles of the formula (II), in which R1, R2 and R4 are as defined in formula (I) and R3 in case (a) is as defined in formula (I) and R3 in case (b) is hydrogen,in the presence of an acidic catalyst with a chlorinating agent to give the monochlorination product (I) or in case (b) with an excess of the chlorinating agent to give the dichlorination product (I) in which R3=chlorine. |
