- A practical synthesis of pyridylboranes via magnesium-halogen exchange
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Dialkylpyridylboranes can be prepared by the reaction of the corresponding pyridylmagnesium chloride with diethylmethoxyborane at 0-25°C. The pyridylmagnesium chlorides are generated from the corresponding bromopyridines via magnesium-halogen exchange rea
- Cai, Weiling,Brown Ripin, David H.
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- Cathodic electrochromic compound used in electrochromic device, and preparation method thereof
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The structural formula of a cathodic electrochromic compound is shown in the description, a pyridine ring in the middle of the cathodic electrochromic compound is connected to any carbon atom in pyridine rings at two sides through a C-C bond; and in the formula, R1 is selected from C2-20 alkyl groups, R2 to R12 are substituent groups on carbon atoms and are respectively independently selected from H, C1-50 alkyl groups, cycloalkyl groups, polycycloalkyl groups, aryl groups, heterocycloalkyl groups, aralkyl groups and alkaryl groups which are free from or contain halogen, N, O, S, Si, P or an unsaturated bond, and X is selected from a methylbenzenesulfonate anion, a tetrafluoroborate anion, a hexafluoroborate anion, a perchlorate anion, a bisoxalatoborate anion, an oxalyldifluroborate anion, a bis(trifluoromethanesulphonyl)imide anion and a tris(trifluoromethanesulfonyl)methyl anion. An electrochromic device using the compound has a long service life and a deep color, and can greatly reduce the visible light transmittance in the power-up state.
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Paragraph 0070; 0071; 0072
(2017/08/30)
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- The synthesis of OSU 6162: Efficient, large-scale implementation of a Suzuki coupling
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The synthesis of the chiral, nonracemic 3-aryl piperidine, OSU 6162 (1), a potential CNS agent from Pharmacia Corporation, is presented. The key construction in the described synthesis is a palladium-catalyzed aryl cross-coupling reaction between bromosulfone (4) and pyridyl borane (14). Initially developed conditions for this Suzuki reaction, conducted in tetrahydrofuran/aqneous hydroxide, delivered free base (6) or hydrochloride salt (15a) in reproducible 80% yield. However, by changing the solvent to toluene and the base to carbonate, significant decreases in catalyst requirement were realized, and the methane sulfonate salt (15b) of the coupled product could be obtained in reproducible 92-94% yield on 200-kg input. The success of the Suzuki reaction was critically dependent on a bulk source of the pyridyl borane coupling partner. Cryogenic conditions were developed for its generation via lithium-halogen exchange to generate thermally labile 3-lithiopyridine followed by transmetalation with diethylmethoxy borane. This highly exothermic series of transformations yielded crystalline diethyl-3-pyridyl borane in reproducible 75-80% yield on scales ranging up to 200-kg input. Selective reduction of the biaryl, classical resolution and introduction of the propyl group via the Gribble reductive amination procedure completed the synthesis of OSU 6162 free base. This route was employed to deliver over 35 kg of clinical-quality bulk drug in short order.
- Lipton, Michael F.,Mauragis, Michael A.,Maloney, Mark T.,Veley, Michael F.,VanderBor, Dale W.,Newby, John J.,Appell, Robert B.,Daugs, Edward D.
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p. 385 - 392
(2013/09/06)
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- Indole derivatives as 5-HT1 -like agonists
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The present invention provides compounds of the formula: STR1 and pharmaceutically acceptable salts thereof.
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