| 摘要 |
Compounds of the formula I <IMAGE> I in which R1 is H, alkyl, alkenyl, alkynyl, haloalkyl, alkoxycarbonyl, alkoxyalkyl, phenyl, benzyl or phenoxyalkyl, it being possible for the three latter radicals to be substituted in the phenyl moiety; R2 is H, alkyl, alkenyl, alkynyl, haloalkyl or alkoxycarbonyl; R3 is H, alkyl, alkenyl, alkynyl, haloalkyl, alkoxycarbonyl, phenyl, phenoxy, benzyl, it being possible for the three latter radicals to be substituted, or alkoxy; and R4 is H, alkyl, alkenyl, alkynyl, haloalkyl or alkoxycarbonyl; or R1 together with R2 is a saturated chain, and the remaining radicals are as defined above; or R1 together with R2 is a chain of the formula -CH=CH-CH=CH-, which may be substituted, and the remaining radicals are as defined above; or R3 together with R4 is a chain of the formula -CH=CH-CH=CH-, which may be substituted, and the remaining radicals are as defined above; are valuable intermediates in the preparation of pharmaceuticals and crop protection agents. The process according to the invention yields compounds of the formula I by reacting a substituted 1-alkoxypyridinium salt of the formula II, <IMAGE> II in which R1 to R4 have the same meaning as in formula I and R5 is alkyl, alkenyl, alkynyl, benzyl or trialkylsilyl and X is a leaving group; together with a cyanide of the formula III M(CN)m (III) in which M is alkali metal, alkaline earth metal or copper and m is 1 or 2, in a polar, aprotic solvent or mixture of solvents.
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