Synthesis of acyclic 6,7-dihaloquinolone nucleoside analogues as potential antibacterial and antiviral agents
摘要:
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 1 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. (C) 2000 Elsevier Science Ltd. All rights reserved.
Synthesis and biological activity of new metronidazole derivatives
摘要:
The development of new antimicrobial and antiparasitic agents offers the possibility of generating structures of increased potency. To this end, three sulphonate ester derivatives of metronidazole were synthesized. Treatment of the tosylate analogue with NaSPh and NaN3 gave the thiophenolate and azide derivatives, respectively. Oxidation of phenylthio derivative with mCPBA afforded the sulfonyl analogue. Similarly, cycloaddition of azido-metronidazole with various symmetric acetylene compounds furnished the 1,2,3-triazole analogues. Treatment of dimethyl dicarboxylate metronidazole derivative with guanidine hydrochloride in the presence of base resulted in the formation of the ring-expanded (fat) derivative, triazolo-diazepam derivative of metronidazole. Treatment of chlorometronidazole with silylated quinolones gave the quinolone analogues of metronidazole. The antigardiasis and antifungal activities of the synthesized compounds were investigated. In addition, all synthesized compounds were evaluated for their in vitro anti-HIV activity in MT-4 cells as non-nucleoside reverse transcriptase inhibitors.[GRAPHICS].