- Several approaches to cyanide ion-catalyzed synthesis of 4-aroyl-1-phenyl-1h-pyrazolo[3,4-d]pyrimidines
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- 4-Aroyl-1-phenyl-1H-pyrazolo[3,4-d]pyrimidines (5) were formed in low yields by reaction of 4-chloro-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine (4) with arenecarbaldehydes (3) in the presence of potassium cyanide. Similar reaction of 4-tosyl-1-phenyl-1H-pyra
- Miyashita, Akira,Suzuki, Yumiko,Ohta, Kiyono,Iwamoto, Ken-Ichi,Higashino, Takeo
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p. 407 - 414
(2007/10/03)
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- Synthesis and reactivities of 1,3-dimethyl-2-(α-hydroxy-benzyl)imidazolium and 1,3-dimethyl-2-(α-hydroxybenzyl)benzimidazolium iodides
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1,3-Dimethyl-2-(α-hydroxybenzyl)benzimidazolium iodide (3a) was synthesized from 1-methylbenzimidazole (10) through two steps involving lithiation and quaternization. Treatment of 3a with 4-chloro-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine (6) afforded 4-benzoyl-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine (15a). 4-Benzoylquinazoline (14a) and 7-benzoyl-3-phenyl-3H-1,2,3-triazolo[4,5-d]pyrimidine (16a) were given by reaction of 3a with 4-chloroquinazoline (5) and 7-chloro-3-phenyl-3H-1,2,3-triazolo[4,5-d]pyrimidine (7). Treatment of 3a with benzaldehyde (9a) gave benzoin (8a). Similar results were obtained in the reactions of 1,3-dimethyl-2-(α-hydroxybenzyl)imidazolium iodide (4a).
- Miyashita, Akira,Kurachi, Akihito,Matsuoka, Yoshiyuki,Tanabe, Noriko,Suzuki, Yumiko,Iwamoto, Ken-Ichi,Higashino, Takeo
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p. 417 - 426
(2007/10/03)
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- Azolium salts as effective catalysts for benzoin condensation and related reactions
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A catalytic ability of several azolium salts for benzoin condensation, the benzoylation of 4-chloro-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine, and oxidative aroylation was examined. We found that azolium salts having an imidazolium moiety, such as 1,4-dimethy
- Miyashita, Akira,Suzuki, Yumiko,Kobayashi, Motoi,Kuriyama, Naomi,Higashino, Takeo
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p. 509 - 512
(2007/10/03)
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- Studies on Pyrazolopyrimidine Derivatives. XIII. Aryl Migration of 4-Aroyl-1H-pyrazolopyrimidines to 4-Aryl-4,5-dihydro-1H-pyrazolopyrimidine-4-carboxylic Acids
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When a mixture of 4-aroyl-1-phenyl-1H-pyrazolopyrimidines (3) and sodium hydroxide in dimethyl sulfoxide (DMSO) was stirred for 1 h at room temperature, migration of the aryl group to the 4-position occurred, i.e., the benzilic acid rearrangement,
- Higashino, Takeo,Matsushita, Yasuhiko,Takemoto, Masumi,Hayashi, Eisaku
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p. 3951 - 3958
(2007/10/02)
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