Synthesis of the new ring system 6,8-dihydro-5H-pyrrolo[3,4-h]quinazoline

Synthesis of quinazolindionyl amino acid derivatives as possible antitumour agents

“…However, the alcohol 2 underwent successful acylation when reacted with acetic acid, benzoic acid or the sterically hindered phthalylglycine in the presence of DCC / DMAP to afford the corresponding esters 13a, 13b and 12 respectively. The structures of 11, 12, 13a and 13b were confirmed by 1 H NMR, 13 C NMR, and elemental analyses (see the experimental part). Moreover, the structures of 13a and 13b were further established by their synthesis by the classical methods i.e.…”

“…Esterification of 3 either with CH3OH / SOCl2 or with (CH3)2SO4 / K2CO3 yielded the methyl ester 4 in 64% and 69% yields respectively. 1 H and 13 C NMR spectra of acid 3 and ester 4 exhibited the presence of their respective hydrogens and carbons in their expected trivial positions. Hydrazide 5 was prepared in 80% yield by boiling the methyl ester 4 in methanol with six-fold excess hydrazine hydrate.…”

“…26 On the other hand, when the acid 3 was coupled with glycine methyl ester hydrochloride in the presence of dicyclohexyl-carbodiimide DCC, and triethyl amine in acetonitrile the isolated product was 1-(1-ethyl-2,4-dioxo-(1H,3H)-quinazolin-3-ylacetyl)-1,3-dicyclohexyl urea (7) instead of desired glycine methyl ester derivative 6a. The structure of the by-product Nacyl urea derivative 7 was elucidated by 1 H NMR, 13 C NMR and elemental analysis. However, pure sample of the desired derivative 6a was obtained solely in a relatively higher yield (59%) when the reaction was repeated in the presence of DCC / HOBt.…”

“…Quinazolines are one of the most studied moieties in cancer chemotherapy. [7][8][9][10][11][12][13] Recently, FDA has approved several quinazoline derivatives as antitumour drugs from past 15 years such as gefitinib, erlotinib, lapatinib and raltitrexed. [14][15][16][17][18] It should be noted that a group of peptideantibiotics such as actinomycin D (Dactinomycin) and bleomycin has been reported as antitumour agents.…”

Synthesis of substituted isoindolo[2,1-a]quinoxalin-6-yl–amino and 6-imino-5-yl thiourea derivatives

“…Quinoxalinylethylpyridylthioureas (QXPTs) of type 1 and 2 ( Figure 2) represent another class of NNRTIs; many compounds showed a potent activity against both HIV-1 wild-type RT and various HIV-1 mutants HIV-1 RT. 16 Considering the good experience reached in the course of our researches on polycyclic nitrogen systems, bearing pyrrole, [17][18][19][20][21][22][23][24] indole, [25][26][27][28][29][30][31][32][33][34][35] isoindole 36-38 and indazole …”