209262-63-5Relevant academic research and scientific papers
Site-Selective Functionalization of Pyridinium Derivatives via Visible-Light-Driven Photocatalysis with Quinolinone
Kim, Inwon,Kang, Gyumin,Lee, Kangjae,Park, Bohyun,Kang, Dahye,Jung, Hoimin,He, Yu-Tao,Baik, Mu-Hyun,Hong, Sungwoo
supporting information, p. 9239 - 9248 (2019/06/24)
The selective installation of phosphinoyl and carbamoyl moieties on the pyridine scaffold is an important transformation in synthetic and medicinal chemistry. By employing quinolinone as an efficient organic photocatalyst, we developed a catalytic system driven by visible light that forms phosphinoyl and carbamoyl radicals, which react with various heteroarenium derivatives under mild, transition-metal-free conditions. This straightforward and environmentally friendly synthetic method represents a new approach to site-divergent pyridine functionalization that offers considerable advantages in both simplicity and efficiency. Ambient temperature is sufficient for the formation of the reactive radicals, and the site-selectivity can be switched from C2 to C4 by changing the radical coupling sources. Under standard reaction conditions, phosphinoyl radicals give access to C4 products, while carbamoyl radicals selectively give C2 products. We found that the carbamoyl radical overcomes the intrinsic preference for forming the ortho-product by allowing the oxo functionality of the carbamoyl radical to electrostatically engage the nitrogen of the pyridinium substrate, which preferentially gives the ortho-product. The phosphinoyl radical cannot engage in the same interaction, because the phosphorus is too large. This novel synthetic route tolerates a broad range of substrates and provides a convenient and powerful synthetic tool for accessing the core structures of numerous privileged scaffolds.
PYRIDINE DERIVATIVES AND THEIR USE AS MEDICAMENTS FOR TREATING DISEASES RELATED TO MCH RECEPTOR
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Page/Page column 91, (2010/10/20)
The present invention encompasses novel substituted pyridine compounds of Formula (I), which act as MCH receptor antagonists. These compositions and pharmaceutical compositions thereof are useful in the prophylaxis or treatment of improving memory function, sleeping and arousal, anxiety, depression, mood disorders, seizure, obesity, diabetes, appetite and eating disorders, cardiovascular disease, hypertension, dyslipidemia, myocardial infarction, binge eating disorders including bulimia, anorexia, mental disorders including manic depression, schizophrenia, delirium, dementia, stress, cognitive disorders, attention deficit disorder, substance abuse disorders and dyskinesias including Parkinson's disease, epilepsy, and addiction.
Preparation of substituted 2-chloropyridines
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, (2008/06/13)
A process for the preparation of a substituted 2-chloropyridine derivatives of the formula STR1 in which R1, R2, R3 and R4 represent hydrogen or various other radicals, which comprises reacting a pyridine-1-oxide of the formula STR2 with an aromatic carbonyl chloride in the presence of an inert organic solvent and in the presence of an acid acceptor at a temperature between about -20° C. and 200° C.
Process for the preparation of substituted 2-chloropyridines
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, (2008/06/13)
A new process has been found for the preparation of substituted 2-chloropyridine derivatives of the formula (I) STR1 wherein R1 to R4 have the meanings as defined in the description. The new process is characterized in that pyridine 1-oxides of the formula II STR2 are reacted with a chlorine-containing phosphoric acid derivative from the series of the chlorophosphoric esters and chlorophosphoramides in the presence of an inert organic solvent and in the presence of an acid acceptor at temperatures between -20° C. and 200° C., and the resulting product is separated further, if appropriate. Compound (I) is known as an intermediate product for medicaments (cf.DE-A 2,812,585) or for insecticidel nitromethylene derivatives (cf. EP-A 163,855).
