- Acylamino-Directed Specific Sequential Difunctionalizations of Anilides via Metal-Free Relay Reactions for p-Oxygen and o-Nitrogen Incorporation
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Novel acylamino-directed relay disubstitutions realize the sequential difunctionalizations of anilides (1) under mild and metal-free conditions for the first time. This [bis(trifluoroacetoxy)iodo]benzene (PIFA) and BF3·Et2O promoted straightforward reaction produces a series of p-acetoxyl- or p-alkoxyl-o-nitro-N-arylamides (2), which are key scaffolds of various drugs, functional materials, and bioactive molecules. The flexibility with respect to the functional groups in these products affords this novel protocol excellent versatility for synthetic applications.
- Wan, Yameng,Zhang, Zhiguo,Ma, Nana,Bi, Jingjing,Zhang, Guisheng
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p. 780 - 791
(2019/01/24)
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- Mizoroki-heck reactions with 4-phenoldiazonium salts
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Significantly better yields were achieved in Mizoroki-Heck reactions using 4-phenoldiazonium salts instead of their O-alkylated analogues under otherwise identical conditions. We found that a one-flask deacetylation-diazotation- precipitation sequence starting from paracetamol or acetanilides derived thereof provides a convenient access to the required diazonium tetrafluoroborates. The utility of these arylating agents in palladium-catalyzed C-C bond forming reactions was demonstrated for a one-flask-synthesis of the heterocyclic core of the drug aripiprazole. Notably, the diazonium salt formation from an acetanilide could be combined with two Pd-catalyzed steps in a one-flask sequence, without any exchange of solvents or isolation of intermediates.
- Schmidt, Bernd,Hoelter, Frank,Berger, Rene,Jessel, Soenke
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supporting information; experimental part
p. 2463 - 2473
(2010/12/25)
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- A New Synthetic Route to 6,7-Dichloro-5,8-quinoxalinedione and Synthesis of Its Derivatives
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6,7-Dichloro-5,8-quinoxalinedione (2), an analogue of Dichlone, was prepared from 4-aminophenol (3) in 27percent overall yield in 8 steps via chloroxidation of the sulfuric acid salt of 8-amino-5-quinoxalinol (9) as a key step.And two derivatives, 6-chloro-5-hydroxypyrazinophenazine (10) and pyridoimidazoquinoxaline-6,11-dione (11), were prepared by reaction of 2 with 1,2-phenylenediamine and 2-aminopyridine in 79percent and 46percent yields, respectively.
- Han, Gyoonhee,Shin, Kye Jung,Kim, Dong Chan,Yoo, Kyung Ho,Kim, Dong Jin,Park, Sang Woo
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p. 2495 - 2502
(2007/10/03)
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- Vinylsilylalkoxy arylbenzotriazole compounds and UV absorbing compositions made therefrom
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Vinylsilylalkoxy arylbenzotriazol monomers such as 2-[3′-t-butyl-5′-(3″-dimethylvinylsilylpropoxy)-2′-hydroxy-phenyl]-5-methoxybenzotriazole are disclosed. These monomers can be incorporated in optically clear silicone polymers to form intraocular lenses, contact lenses, and the like, which have UV absorbing properties.
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