PROCESS FOR THE PREPARATION OF SUBSTITUTED PYRIDINES

摘要

Prepn. of cpds. of formula (I) comprises cyclising R3CH(CN)-CH2-CR1R2-CHO (II) in presence of a catalytic amt. of at least 1 amine base (esp. isopropylamine) and/or an organometallic transition metal catalyst (esp. nickel dichlorobis (triphenylphosphine) (A)). (R1 is 1-4C alkyl, phenyl, H or halogen; R2 is Cl or Br; R3 is Cl, Br or F). (I) are intermediates for cpds. having insecticidal and/or herbicidal activity (see EP--46735). Reaction is at 25-250 (pref. 70-250, esp. 200-220) deg.C pref. in an inert solvent (esp. MeCN).