The structure of a new secondary metabolite from Streptomyces sp. was determined as 4-acetyl-1,3-dihydroimidazo[4,5-c]pyridin-2-one by synthesis of the natural product itself and of the regioisomeric 7-acetylimidazo[4,5-b]pyridine derivative. The former compound was prepared, in 28% overall yield, in a sequence of nitration, reduction, condensation, and Stille reaction of 4-aminopyridine, while the regioisomer was obtained in 5% overall yield by amination, nitration, reduction, condensation, and oxidation of 4-ethylpyridine.
NicolaouKC, SnyderSA. (2005) Chasing molecules that were never there: Misassigned natural products and the role of chemical synthesis in modern structure elucidation. Angewandte Chemie International Edition, 44, 1012–1044.
2.
RahmanH, ShaabanM, ShaabanKA, SaleemM, HelmkeE, Grün-WollnyI, LaatschH. (2009) An imidazopyridinone and further metabolites from Streptomyces. Natural Product Communications, 4, 965–970.
3.
MeanwellNA, HewawasamP, ThomasJA, WrightJJK, RussellJW, GamberdellaM, GoldenbergHJ, SeilerSM, ZavoicoGB. (1993) Inhibitors of blood platelet cAMP phoshodiesterase. 4. Structural variation of the side-chain terminus of water-soluble 1,3-dihydro-2H-imidazo[4,5-b]quinolin-2-one derivatives. Journal of Medicinal Chemistry, 36, 3251–3264
4.
SinghB, BaconER, RobinsonS, FritzRK, LesherGY, KumarV, DorityJA, ReumanM, KuoGH, EissenstatMA, PaganiED, BodeDC, BentleyRG, ConnellMJ, HamelLT, SilverPJ. (1994) Novel cAMP PDE III inhibitors: Imidazo[4,5-b]pyridin-2(3H)-ones and thiazolo[4,5-b]pyridin-2(3H)-ones and their analogs. Journal of Medicinal Chemistry, 37, 248–254.
DemangeP, BatemanA, DellA, AbdallahMA. (1988) Structure of azotobactin D, a siderophore of Azotobacter vinelandii strain D (CCM 289). Biochemistry, 27, 2745–2752.
7.
HanschC, CarpenterW, ToddJ. (1958) Catalytic synthesis of heterocycles. X. Dehydrocyclization of 4-ethyl-3-pyridinethiol to 6-azathianaphthene. Journal of Organic Chemistry, 23, 1924–1926
8.
PinoLN, ZehrungWS. (1955) Preparation of pure 2-aminonitropyridines and 2-aminonitropicolines. Rapid separations by sublimation. Journal of the American Chemical Society, 77, 3154–3155.
9.
LappinGR, SlezakFB. (1950) Some derivatives of the 3- and 5-nitro-2-aminopicolines. Journal of the American Chemical Society, 72, 2806–2807.
10.
LindströmS, AhmadT, GrivasS. (1994) Synthesis of the mutagenic 2-amino-1,6-dimethylimidazo[4,5-b]pyridine (1,6-DMIP) and five of its isomers. Heterocycles, 38, 529–540.
11.
NicolaouKC, BaranPS, ZhongYL. (2001) Selective oxidation at carbon adjacent to aromatic systems with IBX. Journal of the American Chemical Society, 123, 3183–3185.
DeadyLW, KorytskyOL, RoweJE. (1982) Substituent effects on the isomer ratios in the rearrangement of some 2- and 4-nitraminopyridines. Australian Journal of Chemistry, 35, 2025–2034.
14.
DvořákováH, HolýA, VotrubaI, MasojídkováM. (1993) Synthesis and biological effects of acyclic analogs of deazapurine nucleosides. Collection of Czechoslovak Chemical Communications, 58, 629–648.
15.
BracherF, HildebrandD. (1993) Tributyl(1-ethoxyvinyl)stannan als C2-Baustein für die Synthese von β-Carbolin-Alkaloiden. Liebigs Annalen der Chemie, 837–839.