Syntheses and properties of 4-deazatoxoflavins and related compounds.
作者:FUMIO YONEDA、KEISHI NAKAGAWA、AKIRA KOSHIRO、TOSHIO FUJITA、YUKIKO HARIMA
DOI:10.1248/cpb.30.172
日期:——
Treatment of 6-(1-methylhydrazino) uracil (I) with phenacyl bromides in methoxyethanol afforded the corresponding 3-aryl-1-methylpyrimido [4, 5-c] pyridazine-5, 7 (1H, 6H)-diones (3-aryl-6-demethyl-4-deazatoxoflavins) (II) and 3-aryl-5, 7-dioxo-1-methyl-1, 4, 5, 6, 7-pentahydropyrimido [4, 3-c] [1, 2, 4] triazines (III). Methylation of II and III with methyl iodide gave the corresponding 3-aryl-4-deazatoxoflavins (IV) and 1, 6-dimethyl-5, 7-dioxopyrimido [4, 3-c] [1, 2, 4] triazines (V). The reaction of IV with m-chloroperbenzoic acid in chloroform gave the corresponding 3-aryl-4, 4a-epoxy-4-deazatoxoflavins (VI). The oxidizing abilities of II toward alcohols were examined in comparison with those of IV from both kinetic and synthetic viewpoints. Treatment of IV with 30% aqueous caustic alkali led to the exclusive formation of 4, 8-dihydro-4-deazatoxoflavins (VII) and 4, 8-dihydro-4-deazatoxoflavin-4-ones (VIII) via intermolecular oxidation-reduction between the initially formed 4-hydroxy-4, 8-dihydro-4-deazatoxoflavins (IX) and unchanged IV. Treatment of VI with 10% aqueous sodium hydroxide gave the 6-aryl-4-hydroxy-2-methylpyridazine-3 (2H)-ones (X).
将6-(1-甲基肼基)尿嘧啶(I)与苯乙烯溴化物在甲氧基乙醇中反应,得到相应的3-芳基-1-甲基吡啶并[4, 5-c]吡唑-5, 7(1H, 6H)-二酮(3-芳基-6-去甲基-4-去氢氧类黄素)(II)和3-芳基-5, 7-二氧基-1-甲基-1, 4, 5, 6, 7-五氢吡啶并[4, 3-c][1, 2, 4]三嗪(III)。用碘甲烷对II和III进行甲基化反应,得到相应的3-芳基-4-去氢氧类黄素(IV)和1, 6-二甲基-5, 7-二氧吡啶并[4, 3-c][1, 2, 4]三嗪(V)。IV与对氯过苯甲酸在氯仿中反应,生成相应的3-芳基-4, 4a-环氧-4-去氢氧类黄素(VI)。从动力学和合成的角度比较了II对醇的氧化能力与IV的氧化能力。IV与30%水合苛性碱反应,专一性地生成4, 8-二氢-4-去氢氧类黄素(VII)和4, 8-二氢-4-去氢氧类黄素-4-酮(VIII),该反应通过最初形成的4-羟基-4, 8-二氢-4-去氢氧类黄素(IX)与未改变的IV之间的分子间氧化还原反应进行。VI与10%水合氢氧化钠反应,得到6-芳基-4-羟基-2-甲基吡嗪-3(2H)-酮(X)。