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.