Publications by authors named "Takao Nishi"

Pd-catalyzed aminocarbonylation between aryl bromide and NH-benzazepinone was effectively carried out to furnish the key intermediate for tolvaptan (up to 85%) in one step.

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Continuing search for beneficial additive toward the Beckmann rearrangement (BR) of indanone oxime has revealed that common Lewis acid catalyst in methanesulfonyl chloride (MsCl) showed increasing efficiency in this ionic rearrangement. The new protocol with MsCl is superior to the classical phosphorus-based methods such as PPA and Eaton reagent, especially in the reaction of indanone oximes.

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A combined system of bismuth triflate [Bi(OTf)(3)] and boron trifluoride etherate (BF(3).OEt(2)) in dichloromethane is an efficient promoter for the glycosylation of N-acetylneuraminic acid derivatives. The co-existence of two acid catalysts such as Bi(OTf)(3)-BF(3).

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We have surveyed the utility of Beckmann rearrangement for the conversion of indanones into carbostyrils. Initial attempts at the conversion of 6-methoxy indanone oxime under classical conditions resulted in the formation of the two unusual products: 2-sulfonyloxyindanone and the dimeric product. This unusual rearrangement was also observed by the treatment of some metal triflates species.

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The dimeric derivative of aripiprazole was synthesized via the two notable synthetic technologies as a key step: (1) efficient aldehyde bis-arylation by Bi(OTf)(3) and (2) facile Wynberg amination at room temperature. The synthesis has established the structural identity with the minor contaminant sometimes present in Aripiprazole.

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Careful base and solvent optimization for catalytic amination is described. A Pd-catalyzed amination between some arylbromide and unprotected piperazine (1equiv) was efficiently carried out with Pd/BINAP catalyst in a toluene-DBU solvent system, which is useful for the one-pot preparation of unsymmetrical piperazine through amination and in-situ N-protection. Reaction with N-BOC-piperazine was also successful in toluene-DBU or more polar NMP with Cs(2)CO(3) as a key base.

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From August 1986 to February 2000, three patients were given a pericardial-peritoneal window using a subxiphoidal approach, for pericardial effusion associated with chronic exudative pericarditis. Complete drainage without recurrence was achieved in two patients with a large pericardial-peritoneal window (4 cm diameter) and effusion recurred in another with a small pericardial-peritoneal window (3cm diameter). No complications were encountered.

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In our solvent optimization study of NaBH(4) reduction, NMP was found to enhance the reactivity. A chemoselective debromination of the bromide and sulfonates can be attained in the new borohydride reagent system: NaBH(4)-LiOTf-NMP. This mixed system worked as an alternative to NaBH(3)CN and Bu(3)SnH for the S(N)2 type displacement of alkylbromide and sulfonate.

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Purpose: To report the use of a fenestrated stent-graft to manage a traumatic rupture of the juxtahepatic inferior vena cava (IVC).

Case Report: A 62-year-old man was involved in a traffic accident and hospitalized for severe right leg fractures. Computed tomography also uncovered liver contusion and retroperitoneal hematoma.

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Attempted Beckmann rearrangement of the 6-methoxyindanone oximes in conventional conditions resulted in the formation of the two kinds of unexpected products: 2-sulfonyloxyindanone and the dimeric product. Related rearrangement was also observed in the reaction with RhCl-trifluoromethansulfonic acid system.

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