Prepn. of polychlorinated aromatic heterocyclic N-cpds. (is not 3Cl atoms) (I), in which a vapourized aromatic heterocyclic N-cpd. (II) in an inert diluent is

摘要

Prepn. of polychlorinated aromatic heterocyclic N-cpds. (is not 3Cl atoms) (I), in which a vapourized aromatic heterocyclic N-cpd. (II) in an inert diluent is mixed (rapid turbulent mixing) in a reactor with is not 4 moles of Cl2 at 400 - ca 700 deg. (II) contains at least one 6-membered ring containing only C and N as ring forming atoms (pref. 1-2N), and opt. may be substd. by pref. 1-3 alkyl (1-3C), or pref. 1-2 alkenyl (1-3C), CF3, or CN groups, (includes, pyridine, pyridazine, quinoline, and quinoxaline etc. (all opt. substd. as above)) Diluent may be N2, CO2, H2O, etc., pref. a volatile perchlorinated hydrocarbon (claims CCl4 and tetrachloroethylene). Mol ratio diluent:(II) may be 3-54:1. Amount Cl2 used and reaction time/temp. depend on (II) and desired (I); thus in chlorination of pyridine (to give e.g. pentachloropyridine) mole ratio Cl2:pyridine may be 8-10:1, and reaction time/temp. may be is not > 5-6 min., pref. 5-35 secs. (up to 600 deg.C) and 1-2 secs. (at > 600 deg.)/at 500-690 deg. (original gives other pref. conditions for various (I)). N.B. A large excess of Cl2 under stringent temp. conditions may cause chlorinolysis of alkyl and CN groups. (I) and diluent are pref. vapourized at 100-300 deg., pref. 140-280 deg. in a wiped film evaporator. Turbulence of mixing must provide a Reynolds No. of is not 800, pref. ca 2000. Reactor is pref. a cylinder, with length 4-6 times the diameter.