Process for the preparation of pesticidal 1-(haloaryl) heterocyclic compounds

A process for the preparation of a heterocyclic compound of the formula:

• ##STR6## wherein:
• R is haloalkyl, haloalkoxy, haloalkylsulfenyl, haloalkylsulfinyl, haloalkylsulfonyl, F, Cl, Br, I or SF.sub.5 ;
• R.sub.1 and R.sub.2 are each independently hydrogen, F, Cl, Br or I;
• Y is F, Cl, Br or I;
• Z is N, C--NO.sub.2 or C--R.sub.3 wherein R.sub.3 is H, F, Cl, Br, I, CN, C(O)NH.sub.2, C(S)NH.sub.2, alkyl or haloalkyl;
• and A represents an optionally substituted N-linked nitrogen-containing, five- or six-membered heterocyclic ring;
• said process comprising reacting a nitro-containing compound of the formula:
• ##STR7## wherein R.sub.1, R.sub.2, Z and A are defined as above, and G is haloalkyl, haloalkoxy, haloalkylsulfenyl, haloalkylsulfinyl, haloalkylsulfonyl, F, Cl, Br, I, SF.sub.5 or NO.sub.2 ;
• with a metallic halide of the formula MX.sub.n wherein M is a metal cation, X is a halide anion and n is a positive integer equal to the valence of the metal cation, in the presence of a nitrite ion scavenging agent.