PREPARATION OF 4,6-DISUBSTITUTED 5-PYRIMIDINESULFONAMIDES

The first general synthesis of 4,6-disubstituted 5-pyrimidinesulfonami des is described. Treatment of 4,6-dichloro-5-benzylthiopyrimidine (3) with ethoxide or trifluoroethoxide, oxidation of the benzyithio group to a sulfonyl chloride and reaction with ammonia gave 4,6-dialkoxy-5- pyrimidinesulfonamides 5a,b. Stepwise displacement of the trifluoroeth oxy groups in 5a gave a variety of symmetrical and non-symmetrical 4,6 -disubstituted 5-pyrimidinesulfonamides 5h-h.