Design and Synthesis of Pyrido[1,2-e]purin-4(3H)-one Derivatives as Potential PDE 5 Inhibitors

A novel series of pyrido[ 1,2-e]purin-4（3H）-one derivatives containing polar substituents on 5＇-position were designed and prepared as potential PDE5 inhibitors. This paper reports the synthetic routes, 1H-NMR data, and the PDE5 inhibitory activities of the target compounds. The polar piperazinyl group contained （on 5＇-position） compound, 3B2, showed the highest activity among the tested derivatives but less potency than sildenafil 1.

Synthesis of the (3R, 9S, 10S)-Diastereoisomer of Panaxytriol,a Potent Antitumor Polyacetylene from Panax ginseng

(3R, 9S, 10S)-Heptadec-1-ene-4,6-diyne-3, 9, 10-triol 2, a diastereoisomer of panaxytriol 1 was synthesized using L-(+)-diethyl tartrate 5 as a chiral template, through the Cadiot-Chodkiczwicz coupling of the terminal acetylene 3 with bromoacetylene 4.

Synthesis of 2-Substituted Hexahydro-1H-1,4-diazepine Analogues

substituted hexahydro-1H-1,4-diazepine analogues were synthesized starting from N,N?-dibenzyl-1,3-propylene diamine and methyl-2,3-dibromo propionate through nucleophilic substitution, reduction, chlorination and debenzylation.

Synthesis of 5-Substituted Hexahydro-1H-1, 4-Diazepine Analogues

5-Substituted hexahydro-1H-1,4-diazepine analogues were synthesized starting from N,N'-dibenzyl-1, 2-ethylenediamine and methyl 2, 4-dibromide butyrate through nucleophilic substitution, reduction, chlorination, debenzylation and amidation. Bioactivity tests showed that 9a had the highest agonist activity.

Synthesis of novel analogues of zanamivir as neuraminidase inhibitors

A versatile synthesis of novel zanamivir analogues modified at C-4 and C-8 positions was described.The formation of amides from the acid with corresponding amines,followed by click chemistry generated the triazole substituted compounds as novel analogues of neuraminidase inhibitors in good yields.