Quinolone Nucleosides: 6,7-Dihalo-N-β- and α-Glycosyl-l 4-dihydro-4-oxo-quinoline-3-carboxylic Acids and Derivatives. Synthesis, Antimicrobial and Antiviral Activity

Microwave-Assisted Synthesis of Fluoroquinolones and Their Nucleosides as Inhibitors of HIV Integrase

Six fluoroquinolone ribonucleosides were synthesized by using microwave irradiation starting from fluoroanilines. In most cases the microwave application proved superior in time and yield, especially the one step decarboxylation of the carboxyquinolone esters3a-3cand the Vorbrüggen glycosylation. The former led to the new type of fluoroquinolone ribosides8a-8c. Compound8cin the crystal structure showed C3'-endo and anti conformation. The nucleosides were examined, but found inactive against the replication of HIV-1(IIIB) in cell culture, while they were toxic for the cells at a 50% cytotoxic concentration ranging from 31 to >125 μg/ml. But measurements of the inhibitory effects against HIV-1 integrase enzymatic activity showed an interesting activity for compound8c.

Synthesis of acyclic 6,7-dihaloquinolone nucleoside analogues as potential antibacterial and antiviral agents

Reaction of the quinolone carboxylic acids 1 and 2 with (2-acetoxyethoxy)methyl chloride 3 in the presence of n-Bu4NI afforded the N-alkylated products 4 and 6, which could be deblocked to the free nucleoside analogues 5 and 7, respectively. The alkylated quinolone carboxylic acids 9 and 10 were obtained by condensation of I and 2 with 1,4-dichlorobut-2-ene 8 in the presence of NaH. Hydrolysis of 9 gave the alcohol 11. Similar treatment of 1 with 8 in the presence of K2CO3 at relatively high temperature furnished 12. Prolonged heating of the ester 13 with 8 in NaH/DMF afforded the conjugated-diene 15. Treatment of 1 and 2 with dimethyl acetylenedicarboxylate 16 furnished the pyrano[4,3-b]quinolones 17 and 18, respectively. Antibacterial and antiviral evaluations of the new products are reported.