Aroylation of fused pyrimidines; Synthesis of 4-aroylfuro[2,3-d]-, 4-aroylthieno[2,3-d]-, and 4-aroylisoxazolo[5,4-d]pyrimidines

4-Aroylfuro[2,3-d]-(4), 4-aroylthieno[2,3-d]-(7 and 8), and 4-aroylisoxazolo[5,4-d]pyrimidines (13) were synthesized by aroylation of the fused chloro-(3a and 12) or bromopyrimidines (3b, 5, and 6) with arenecarbaldehydes (2) catalyzed by an imidazolium salt (1a). The fused aroylpyrimidines (4 and 7) were also synthesized by oxidative decyanation of alpha-phenylheteroareneacetonitriles (10 and 11).