SYNTHESIS OF 2,3-DIHYDRO-IMIDAZO[1,2-C]PYRIMIDO[5',4'-4,5]THIEN[2,3-E]PYRIMIDINES AND 2H-3,4-DIHYDRO-PYRIMIDO[1,2-C]PYRIMIDO[5',4'-4,5]THIENO[2,3-E]PYRIMIDINES

The reaction of dibenzoyldiacetonitrile with cyanothioacetamide gave 5-cyano-6-methyl-2-phenyl-pyri-mid-4(3H)-thione (4) in good yield. The title compounds were synthesized on two different routes. On one way, 3-amino-thieno[2,3-d]pyrimidine-2-carbonic acid alkylesters obtained from 4 were after acetylation of the amino group to 9 transformed by reaction of aminoethanol to the hydroxy ethylated pyrimidothienopyrimidone 10b. This compound after chlorination to 11 by reaction with 1,2-diaminoethan or 1,3-diaminopropan yielded the desired tetracyclic substances 12 and 13. On the other way, 3-aminothieno[2,3-d]pyrimidine-2-carboxamide 14 obtained from 4 gave via the pyrimidothienopyrimidone 15, the chloro compound 17 and the omega-hydroxyalkyl compounds 21 and 22 the title substances 23 and 24.