8-Aminoquinolines as anticoccidials-I

Primaquine revisited six decades after its discovery

“…The anticoccidial activity of PQ has also been tested by Armer et al who found that both PQ and pamaquine possess in vivo anticoccidial activity in broilers against the protozoan parasites E. tenella and E. necatrix [64,65]. These authors established that the drugs are not active themselves against Eimeria, but generate active metabolites in vivo, thus actuating as prodrugs.…”

Regioselectivity in the Nitration of Dialkoxybenzenes

“…The preparation of macrocycles 4 requires diamines 2 , which are easily synthesized by the reduction of dinitroaryl compounds 1 (Scheme ). In addition to their application in Schiff base macrocycle synthesis, 1,2-dialkoxy-4,5-dinitrobenzene compounds (e.g., 1a − d ) and their reduced diamine derivatives (e.g., 2a − d ) are useful precursors for many compounds, including liquid crystals, optical materials, and pharmaceuticals . Typically, the dinitroaryl compounds 1 are readily prepared by the nitration of 1,2-dialkoxybenzene derivatives in concentrated nitric acid, which almost exclusively yields the desired 4,5-dinitro product .…”

Synthesis, antimalarial, antileishmanial, antimicrobial, cytotoxicity, and methemoglobin (MetHB) formation activities of new 8-quinolinamines

“…Filtrate was washed with saturated sodium bicarbonate solution (3 × 5 mL) followed by water (2 × 5 mL), and dried over Na 2 SO 4 . The solvent was removed under reduced pressure to afford the crude product, which was purified by flash column chromatography on silica gel using EtOAc/hexanes (30:70) to afford the (S/R)-{alkoxycarbonylamino-1-[4-(2-tert-butyl-6-methoxy-8-quinolylamino)pentylcarbamoyl]-alkyl}carbamic acid benzyl/tert-butyl esters (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and (S/R)-{alkoxycarbonylamino-1-[4-(4-ethyl-6-methoxy-5-pentyloxy-8-quinolylamino)pentylcarbamoyl]alkyl}carbamic acid benzyl/tert-butyl esters (38-50). {4-(N,N ' -Bisbenzyloxycarbonylguanidino)-1-[4-(4-ethyl-6 [1-[4-(4-Ethyl-6-methoxy-5-pentyloxy-8-quinolylamino)pentylcarbamoyl]-2-(1H-indol-3-yl) 27 (m, 5H), 7.11 (d, 1H, J = 4.2 Hz), 6.47 (brs, 1H), 6.42 (s, 1H), 6.07 (brs, 1H) {2-Benzylsulfanyl-1-[4-(4-ethyl-6-methoxy-5-pentyloxy-8 …”

“…1), constitute an interesting and versatile class of drugs, 5 which in addition to antimalarial activity against P. vivax and P. ovale, also exhibit antileishmanial 6,7 and anticoccidial activities. 8 PQ has a limited role in current malaria chemotherapy due to its limited activity against asexual blood stages of the malaria parasite, severe hematotoxicities in patients with the glucose-6-phosphate dehydrogenase (G-6-PD) deficiency, 9 and a short half-life due to its rapid metabolism to inactive and toxic metabolites. [10][11][12][13] Despite of these negative attributes, PQ is deemed a worthy candidate for additional structural optimization because it is the only antimalarial drug which exhibit a certain degree of activity against almost all the stages in the life cycle of the human malaria parasite.…”