| 摘要 |
A process is described for the preparation of substituted heteroaromatics of the general formula (I) where X is oxygen, sulphur or NR5 where R5 is hydrogen, C1-C20-alkyl or C5-C6-aryl and R4 is C1-C20-alkyl, C5-C6-aryl or heteroaryl, R1, R2, R3 is hydrogen, halogen, C1-C20-alkyl, C5-C6-aryl or heteroaryl, by reaction A) of a halogenated heteroaromatic of the general formula (II) where X has the meaning given for formula (I) and R6 is bromine, iodine or chlorine and R1, R2 and R3 have the meaning given for formula (I), with a Grignard reagent of the general formula (III) R4MgHal  (III) where R4 has the meaning given for formula (I) and Hal is bromine, iodine or chlorine or B) reaction of the halogenated heteroaromatics of the formula (II) with magnesium firstly to give a Grignard compound of the general formula (IIIa) where Hal is bromine, iodine or chlorine and X and R1, R2 and R3 have the meaning given for formula (I), and further reaction with a halogenated compound of the general formula (IV) R4Hal  (IV) where R4 has the meaning given for formula (I) and Hal is bromine, iodine or chlorine, where the reactions A) or B) are in each case carried out in the presence of an Ni or Pd catalyst, characterized in that the process is carried out in the presence of cycloalkyl alkyl ether as solvent and optionally a further solvent. Likewise described is the use of cycloalkyl alkyl ethers, in particular cyclopentyl methyl ether, in the Kumada reaction for the preparation of substituted heteroaromatics, in particular substituted thiophenes.
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