SYNTHESIS AND ANTIMICROBIAL ACTIVITY OF 6,7-ANNULATED PYRIDO[2,3-D]PYRIMIDINES

Four new 6H-indeno[2',1':5,6]pyrido[2,3-d]pyrimidines (10-13) were syn thesized via cyclocondensation reactions invoking chlorovinyl aldehyde 1 or ketoaldehyde 3 and appropriately substituted 6-aminopyrimidines. The regiochemistry of the compounds was established by H-1 NMR and C- 13 NMR spectral data as well as X-ray crystal data. Compounds 10 and 1 1 and previously reported homologues 14 and 15 were screened for antim icrobial activity. Moderate antimicrobial activity was observed for so me of these compounds. Compound 14 was especially active against Staph ylococcus aureus. Crystal data for 13 (C14H7N3Cl2) follows: monoclinic space group, P2(1)/n; Unit cell dimensions a = 7.284(1) Angstrom, b = 12.800(1) Angstrom, c = 13.108(1) Angstrom, beta = 93.98(1)degrees, V = 1219.2(2) Angstrom(3), Z = 4.