Polycyclic N-heterocyclic compounds 83: Synthesis of 2,4-disubstituted 5,6-dihydro[1]benzofuro[3′,2′:2,3]oxepino[4,5-d]pyrimidines and 2,4,5-Trisubstituted 5,6-Dihydro[1]benzofuro[2′,3′:5,6]pyrano[4,3-d] pyrimidines from 4-Chloro-5,6-dihydro[1]benzofuro[3′,2′:2,3] oxepino[4,5-d]pyrimidines

Treatment of 2-substituted 4-chloro-5,6-dihydro[1]benzofuro[3′, 2′:2,3]oxepino[4,5-d]pyrimidines with simple alcohols and thiols as nucleophile afforded 2-substituted 4-alkoxy (or sulfanyl) derivatives. In the case of alkoxide nucleophiles, rearranged reaction products were also obtained. X-ray crystallography was used to support the structure assignment of the rearranged product.