Metalation of t‐butyl sulfoxides, sulfones and sulfonamides of pyridazine and pyrazine. Metalation of diazines. XX

In the pyridazine series, the use of tert ‐butylsulfinyl and tert ‐butylsulfonyl as ortho directing groups for metalation has been tested. Various functionalized products were obtained in good yields. In the case of 3‐ tert ‐butylsulfinyl‐6‐methoxypyridazine, the metalation was regioselective in ortho to the sulfinyl group. The metalation of 2‐ tert ‐butylsulfinyl and 2‐ tert ‐butylsulfonylpyrazine gave low to moderate yields. Synthesis of diazinesulfonamides were improved and the metalation of N‐tert ‐butylsulfonamidopyrazine was achieved.