An Efficient Route to Thieno[2,3-d]pyrimidine Derivatives by Tandem [2,3] and [3,3] Sigmatropic Rearrangement (SUPPORTING DATA)

Synthesis of biologically important thieno[2,3-d]pyrimidine derivatives 6a-f in 65-78% yields have been reported. The conditions applied here are based on the less studied tandem rearrangement protocol. The precursor sulfides in 73-85% were prepared from N,N-dimethyl-6-cholouracil and 1-aryloxy-4-chlorobut-2-yne by phase transfer catalyzed reaction condition.