| 摘要 |
Novel 5-halogeno-6-amino-nicotinic acid halides of the formula <IMAGE> (I) in which R represents hydrogen or alkyl, R1 represents hydrogen, alkyl or acyl or R and R1, together with the nitrogen atom to which they are bonded, represent an optionally substituted heterocyclic radical, R2 represents halogen and Hal represents halogen, are prepared by halogenating the corresponding nicotinic acids. The Co Hal moiety is converted to CH3 by reaction with R3OMgCR4(COOR3)2 (IV) in which R3 represents C1-3 alkyl and R4 represents hydrogen or C1-C2-alkyl, and then hydrolyzing and decarboxylating the product.
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