الفهرس 
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Abstract
The synthetic strategies and the biological evaluations on the pyrido[1,2-
c]quinazolinone derivatives are limited, only two synthetic approach were
reported. The first one included the synthesis from ethyl 2-(quinazolone)-5-oxo-
2,5-dihydroisoxazole-4-carboxylates as starting materials, in which reaction
first with NaN3 followed by base-catalyzed rearrangement. The second method
based on the ring closure of the 2-o-amino-phenyl-6-phenylpyrimidine-
4(3H)one with formic acid. Both producers are long synthetic way and limited
to synthesize various derivatives. Since many analogues of this ring system
showed marked biological activity, we have investigated the synthesis of this
scaffold, and herein we present our results.
Quinazolin-4-ol (1) was prepared as described in the literature, Upon
refluxing with freshly distilled thionyl chloride in presence of catalytic amount
of DMF, compound 1 yielded the corresponding 4-chloro derivative 2. Which
followed by its reaction with sodium azide in DMF to give 4-azidoquinazoline
(3) in 71 % yield. Treating of compound 3 with triphenylphosphine gave
phosphrane derivative 4 in 69 % yield. On hydrolysis of the latter compound 4
by glacial acetic acid gave quinazolin-4-amine (5) in 76 % yield. The
interaction of aminoquinazoline 5 with malonate derivatives afforded
pyrimidoqunazoline derivatives 6a-d in 67-92 % yields (Scheme 1).