- Reactions of 3-(2-Methyl-1,3-dioxolan-2-yl)tropolone Methyl Ethers with Hydrazines, Thiourea, Guanidine, and Amidines
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3-(2-Methyl-1,3-dioxolan-2-yl)tropolone, prepared from 3-acetyltropolone, was methylated with diazomethane to afford 2-methoxy-3-(2-methyl-1,3-dioxolan-2-yl)tropone (3a) and 2-methoxy-7-(2-methyl-1,3-dioxolan-2-yl)tropone (3b).The methyl ether 3a reacted with hydrazine to afford 2-hydrazono-3-(2-methyl-1,3-dioxolan-2-yl)-3,5-cycloheptadien-1-one and 3-methyl-1,8-dihydrocycloheptapyrazol-8-one.The reaction with methylhydrazine afforded 3-(2-methyl-1,3-dioxolan-2-yl)-2-methylhydrazono-3,5-cycloheptadien-1-one and 1,3- and 2,3-dimethyl-dihydrocycheptapyrazol-8-ones.Another methyl ether 3b reacted with hydrazine to afford 2-hydrazino-7-(2-methyl-1,3-dioxolan-2-yl)tropone, while the reaction with methylhydrazine gave 2-(2-methyl-1,3-dioxolan-2-yl)-7-(2-methylhydrazino)tropone, 2-(2-methyl-1,3-dioxolan-2-yl)-7-(1-methylhydrazino)tropone, and 1,3-dimethyl-8-methylhydrazono-1,8-dihydrocycloheptapyrazole.On the other hand, the methyl ether 3a reacted with guanidine, acetamidine, and benzamidine to give 4-(2-methyl-1,3-dioxolan-2-yl)-2-amino-, 2-methyl-, and 2-phenylcycloheptimidazole, respectively.The reaction of the methyl ether 3b also gave the same products.The reaction of 3b with thiourea afforded 2-mercapto-4-(2-methyl-1,3-dioxolan-2-yl)cycloheptimidazole but 3a resulted in the rearrangement to ethyl 2-(2-methyl-1,3-dioxolan-2-yl)benzoate.
- Imafuku, Kimiaki,Kikuchi, Yosuke,Yin, Bing-Zhu
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p. 185 - 192
(2007/10/02)
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- Reactions of 3-Acetyl-2-aminotropones and 2-Acetyl-7-aminotropones with Hydrazine
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3-Acetyl-2-aminotropone (1a) reacted with hydrazine to afford its hydrazone (3a) and 3-methyl-1,8-dihydrocycloheptapyrazol-8-one (4), while methylamino- and pyrrolidinyl-substituted compounds 1b and 1c gave only the cyclized compound (4).Reactions of 2-acetyl-7-aminotropones 2a-d gave their hydrazones 5a-d and the hydrazone 6.The hydrazones 3a and 5b were heated in acetic acid to give 4 and 3-methyl-8-methylamino-1,2-diazaazulene (7), respectively.Several reactions of 4 and 6 were also described.
- Imafuku, Kimiaki,Shimazu, Akiko
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p. 653 - 656
(2007/10/02)
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- Reactions of 3-Acetyltropolone and Its Methyl Ethers with Aminoguanidine
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3-Acetyltropolone (1) reacted with aminoguanidine to afford its guanylhydrazone (3).The reaction of 3-acetyl-2-methoxytropone (2a) gave 4-methyl-1(2H)-phthalazinone (5), while the reaction of 7-acetyl-2-methoxytropone (2b) gave its guanylhydrazone (6) and 3-methyl-1,8-dihydrocycloheptapyrazol-8-one (4).The guanylhydrazones (3 and 6) were easily cyclized to 4 by heating in acetic acid.
- Jin, Zhong-Tian,Imafuku, Kimiaki
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p. 969 - 970
(2007/10/02)
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