abstract |
A process for preparing compounds of the formula (II), n nwhere the substituents R 1 to R 5 are each independently H, CH 3 , straight-chain or branched C 1 –C 8 -alkyl, CH(OC 1 –C 5 -alkyl) 2 , CH(C 1 –C 5 -alkyl)(OC 1 –C 5 -alkyl), CH 2 (OC 1 –C 5 -alkyl), CH(CH 3 )(OC 1 –C 5 -alkyl), C 1 –C 8 -alkoxy, N(C 1 –C 5 -alkyl) 2 , phenyl, substituted phenyl, aryl, heteroaryl, S(C 1 –C 5 -alkyl) or a radical C aryl, alkyl , andn nthe symbols X 1 to 5 are each carbon or a maximum of two neighboring X 1-5 are nitrogen or X 1 R 1 and X 2 R 2 together are O, NH, N(C 1 –C 5 -alkyl), N(C═O—C 1 –C 5 -alkyl), N(SiR 3 ) 2 or S,n nor where neighboring radicals R 1 to R 5 form the following structural unit, n nwhere X 6 to X 9 and R 6 to R 9 have the same meaning as X 1 to X 5 and R 1 to R 5 which comprises reacting chloro- or fluoroaromatics of the formula (I) with carbon electrophiles and lithium metal. |