1593-1606 2-Amino-4-(2'-methoxynapthalen-6'-yl)-6-(4-subtituted
phenyl)-pyridin-3-carbonitriles 2a-c
have been prepared by cyclocondensation of substituted chalcones 1a-c with malanonitrile in the presence
of ammonium acetate. The compounds 2a-c
on cyclocondensation with (5'-substituted 2'-phenyl-1<i style="mso-bidi-font-style:
normal">H-indol-3'-yl)-acrylonitriles 3a-c
afford the key intermediates 4-amino-5-(2'-methoxynaphthalen-6'-yl)-7-aryl-2-(5'-substituted
2'-phenyl-1H-indol-3'-yl)-1,8-naphthyridin-5-carbonitriles
4a-i. Compounds <b style="mso-bidi-font-weight:
normal">4a-i when subjected to annulations using simple and inexpensive
reagents such as formic acid, carbon disulfide and formamide afford title
compounds 5a-i, <b style="mso-bidi-font-weight:
normal">6a-i and 7a-i,
respectively. The structures of all these previously unknown compounds have
been established on the basis of spectral and analytical data. All synthesized
compounds have been screened for their antimicrobial and antioxidant
activities. Compounds 2b, 5d and <b style="mso-bidi-font-weight:
normal">6a exhibit maximum zone of inhibition against the microorganisms E. coli, <i style="mso-bidi-font-style:
normal">A. flavus and A. terrus
whereas compound 7c shows maximum
zone of inhibition against microbes E.
coli, S. aureus, A. oryzae and<i style="mso-bidi-font-style:
normal"> A. niger. Compounds 4h,
5g, <b style="mso-bidi-font-weight:
normal">5h, 6g and 6h exhibit good radical scavenging
activity as compared to the standards