Kenya Mori

A novel synthesis of pyrimido[4,5-b]quinoline-2(3H),4(10H)-diones (5-deazaflavins) and analogues by the oxidative cyclization of 5,5′-arylmethylenebis-(6-alkylamino-3-methyluracils)

The oxidative coupling of 5,5′-arylmethylenebis-(6-alkylamino-3-methyluracils), prepared by the condensation of 6-alkylamino-3-methyluracils and arenecarbaldehydes, with diethyl azodiformate afforded the corresponding pyrimido[4,5-b]quinoline-2(3H),4(10H)-diones (5-deazaflavins). This synthetic method was successfully applied to the preparation of 5-deazaflavin-type compounds such as a benzologue, a thiophen analogue, or a nitrogen analogue of 5-deazaflavin. The 8-chloro-5-deazaflavin was converted into the corresponding 8-amino-derivatives by treatment with amines.

Dehydrogenation of alcohols by pyrimido[4,5-b]quinoline-2(3H),4(10H)-diones (5-deazaflavins) as autorecycling oxidizing agents

Pyrimido[4,5-b]quinoline-2(3H),4(10H)-diones (5-deazaflavins) and related compounds oxidize alcohols under alkaline conditions in the dark to yield the corresponding carbonyl compounds, while they themselves are hydrogenated to the 1,5-dihydro-derivatives. The substituent effect in the 5-deazaflavin series was examined in terms of the oxidizing ability toward benzyl alcohol. In some cases, the benzyl alcohol oxidation by the 5-deazaflavins have been shown to recycle automatically, and a > 100% yield of benzaldehyde (based on the 5-deazaflavin) was obtained.

Investigation of a facile synthetic method for phosphorothioate dimer synthons in oligonucleotide phosphorothioates synthesis.

Abstract A facile synthetic method of a phosphorothioate dimer block was investigated. Dinucleoside phosphite triester intermediates were obtained in one-pot synthesis by the coupling of a protected nucleoside bearing free 5′-OH and a protected nucleoside bearing free 3′-OH in the presence of phosphorous trichloride (PCl3) and 1,2,4-triazole. The intermediates were easily sulfurized to afford the desired phosphorothioate dimer blocks in 33-64% overall yields.

Novel synthesis of pyrimido[4,5-b]quinoline-2(3H),4(10H)-diones (5-deazaflavins)

Treatment of 5-benzylidene-6-(N-substituted amino)uracils with diethyl azodiformate led to the formation of the corresponding pyrimido[4,5-b]quinoline-2(3H),4(10H)-diones (5-deazaflavins).