470 00d or a compound easily converted to formula 470 00d the substituted ketone of formula 470 00 can then be converted to the desired compound by the methods described above and in wo 88 03138 and in u s pat no 3 326 924 formula 405 00 wherein r 1 or r 2 are chlorine can be made by the following alternate process the n oxide of formula 415 00 can be treated with pocl 3 to form a compound of formula 415 01 typically this reaction results in mono substitution of cl in the ortho or para position relative to the n atom of the ring alternatively the cl substituted azaketones of formula 470 00b or 470 00c above can be converted t o the corresponding derivatives of formula 405 00 above wherein r 1 and or r 2 is cl by methods analogous to those described above at this point the cl substituent s can be displaced by an appropriate nucleophile to provide the desired substituent suitable nucleophiles include alkoxide amines thiols etc this reaction usually requires higher temperatures e g from about 100 u00b0 to about 200 u00b0 c than the displacement reaction to produce ketone 470 00d above it is also usually conducted in a sealed vessel in an inert solvent the compound of formula 405 00 is then converted to a compound of formula 400 00 as described above various electrophilic species can also be added to the pyridine.