- BICYCLIC COMPOUND AND PHARMACEUTICAL USE THEREOF
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The present invention provides a compound represented by the formula wherein R1 is a hydrocarbon group optionally having substituent(s), amino optionally having substituent(s), hydroxy optionally having a substituent or a heterocyclic group optionally having substituent(s); R2 is a hydrogen atom or a hydrocarbon group optionally having substituent(s); Xa and Xb are each C, N, O or S; Xc and Xd are each C or N; m is 0-2; n is 1-3; ring A is a 5-membered ring optionally having substituent(s); ring B is a 6-membered ring optionally having substituent(s); and ring C is a 3- to 5-membered ring optionally having substituent(s), provided that when Xa, Xc and Xd are each C, then Xb is N or S, or a salt thereof, which is useful as an agent for the prophylaxis or treatment of a disease relating to an action of melatonin, and the like.
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Page/Page column 93
(2010/01/29)
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- Reaction of 3-Substituted Imidazopyridines with Br+ and the Alleged 5-Bromo-Substituted Product
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The reaction of 3-methylimidazopyridine with NBS was reinvestigated and is shown to give products formed by apparent nucleophilic substitution at the 2-position.NBS in CHCl3 gave compounds 4 and 6, while NBS in CCl4 or Br2 in CHCl3 gave exclusively 4.Mechanisms and differences in product formation are discussed; evidence that the previously reported NBS product was in fact 3-bromo-5-methylimidazopyridine, rather than the alleged 5-bromo-3-methyl derivative 3, is presented.Compound 3 was prepared by diazotization of 5-amino-3-methylimidazopyridine in the presence of HBr and by condensation of 2-bromopropanal (or its acetal) with 2-amino-6-bromopyridine (12).This latter reaction of the weakly basic aminopyridine 12 is shown to follow the normal pattern in which the amino nitrogen condenses with the carbonyl carbon.Structures are established by infrared, mass, and 1H-NMR spectral analyses, mechanistic considerations, and diagnostic reactions.Experimental and computer-generated 1H-NMR spectra of compounds 3 and 13 are reproduced.
- Hand, E. Smakula,Paudler, William W.
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p. 3738 - 3745
(2007/10/02)
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