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Indian Journal of Chemistry -Section B (IJC-B) >
IJC-B Vol.49B [2010] >
IJC-B Vol.49B(09) [September 2010] >
| Title: | Synthetic studies of some varied structural systems of biologically potent polynitrogen heteropolycyclics |
| Authors: | Gupta, Shallu
Gupta, Poonam
Sachar, Anand
Sharma, Rattan L |
| Keywords: | Knoevenagel
subsequent Michael and heterocyclisation reactions
‘ortho’ and ‘ortho and peri’ fused heteropolycyclics |
| Issue Date: | Sep-2010 |
| Publisher: | CSIR |
| Abstract: | Four-component one pot cyclocondensation of aromatic
aldehydes 1, malononitrile 2, barbituric acid 3 and ammonium acetate in methanol after initial Knoevenagel, subsequent
Micheal and final heterocyclisation reactions give substituted and functionalized
pyrido[2,3-d]pyrimidine derivatives 4. These pyridopyrimidines on reaction with
various active methylene compounds result in the formation of differently functionalized
and diversly substituted linear tricyclic pyrimidonaphthyridines 5-7 and 9-10, linear tetracyclic benzo[b]pyrimidonaphthyridines
8 and dipyrimidonaphthyridines 11 as a result of final heterocyclization
through either simple cyclocondensation or cyclodehydration, etc. The compounds of system 7/10 and two compounds of system 8 with suitable functionalities on further
condensation with formamide, generate the novel angularly fused tetracyclic dipyrimidonaphthyridines
12/14 and ‘ortho and peri’ fused pentacyclic
pyrimidonaphthyridinoquinazolines 13
respectively, all hitherto unknown or not reported in literature. Compounds 4 and 5 on condensation with formamide can close the recurring generation
of the CN and other reactive functionality on the products resulting in the production
of tricyclic pyrido [2,3-d;6,5-d′]dipyrimidine 15 from 4 and two differently
fused linear and angular tetracyclic dipyrimidonaphthyridine systems 16 and 17 from 5 similar to the
systems 11 and 12/14 respectively. Either of the latter two systems on heterocyclodehydration
with boiling formic acid produce same ‘ortho
and peri’ fused pentacyclic novel heterocyclic
system 1,3,4,6,7,8,9,11-octazabenzo[de]naphthacene
18. |
| Page(s): | 1243-1256 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-0983(Online); 0376-4699(Print) |
| Source: | IJC-B Vol.49B(09) [September 2010]
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