Preparation of substituted 2-chloropyridines

A process for the preparation of a substituted 2-chloropyridine of the formula ##STR10## in which R.sup.1 represents hydrogen, fluorine, chlorine, cyano, COOCH.sub.3, COOC.sub.2 H.sub.5, CON(CH.sub.3).sub.2 or CON(C.sub.2 H.sub.5).sub.2,

• R.sup.2 represents hydrogen, fluorine, chlorine, CH.sub.3, C.sub.2 H.sub.5, CH.sub.2 Cl, CH.sub.2 CN, CH.sub.2 --OCH.sub.3, CH.sub.2 --OC.sub.2 H.sub.5, CH.sub.2 --N(i--C.sub.3 H.sub.7).sub.2, CH.sub.2 --N(i--C.sub.4 --H.sub.9).sub.2, ##STR11## or in which R.sup.1 and R.sup.2 together represent the divalent group --CH.dbd.CH--CH.dbd.CH--,
• R.sup.3 represents hydrogen, chlorine, COOCH.sub.3, COOC.sub.2 H.sub.5, CON(CH.sub.3).sub.2 or CON(C.sub.2 H.sub.5).sub.2, and
• R.sup.4 represents hydrogen, fluorine, chlorine or cyano, or in which R.sup.3 and R.sup.4 together represent the divalent group --CH.dbd.CH--CH.dbd.CH--, which comprises reacting a pyridine-1-oxide of the formula ##STR12## with an aromatic carbonyl chloride in the presence of an inert organic solvent and in the presence of an organic acid acceptor at a temperature between about -20.degree. C. and 200.degree. C., provided that only one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can represent cyano or carbalkoxy at one time.