22934-23-2Relevant articles and documents
Innovative approaches to the imidazo[4,5-b]pyridine ring system. Development of an efficient process for industrial-scale production of a key intermediate for potent angiotensin II receptor antagonists
Stucky, Gerhard C.,Roduit, Jean-Paul,Schmidt, Beat
, p. 280 - 282 (2007/10/03)
Two syntheses of 2-ethyl-5,7-dimethyl-3H-imidazo[4,5-b]pyridine (3), an important intermediate for the synthesis of several potent angiotensin II antagonists, have been investigated. The first route involves conversion of 1,1-bis(methylthio)-2-nitroethene (17) to 2-ammo-4,6-dimethyl-3-nitropyridine (6); catalytic hydrogenation of 6 in propionic acid gave 3 in high yield. In the second synthesis, propionitrile is converted to imidate hydrochloride 15·HCl which is neutralised and reacted with aminoacetonitrile in the presence of acetylacetone to give 3 in 55% overall yield. The propionitrile route was scaled up to produce 3 in the pilot plant.
Process for preparing imidazopyridine derivatives
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, (2008/06/13)
A process for preparing imidazopyridine derivatives of the general formula: STR1 wherein R1 is hydrogen or an alkyl group, and R2, R3 and R4 are identical or different and are hydrogen, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or a halogen atom. In this process, a 2-amino-3-nitropyridine is hydrogenated in the presence of a hydrogenation catalyst and the hydrogenation product is condensed with a carboxylic acid simultaneously present in the reaction mixture to give the end product. The imidazopyridine derivatives are intermediates for the preparation of angiotensin II antagonists.
Polyfunctional pyridines from nitroacetamidine and β-diketones. A useful synthesis of substituted imidazo[4,5-b]pyridines and related compounds
Batt,Houghton
, p. 963 - 969 (2007/10/02)
Nitroacetamidine undergoes a useful cyclocondensation with β-diketones to produce substituted 2-amino-3-nitropyridines. Use of an acylpyruvate generates hitherto unreported 2-amino-3-nitropyridine-4-carboxylates. These may be converted easily to functionalized imidazo[4,5-b]pyridines and oxazolo[5,4-b]pyridines.
Substituted imidazo-fused 6-membered heterocycles as angiotensin II antagonists
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, (2008/06/13)
Substituted Imidazo-fused 6-membered heterocycles of structural formula: STR1 wherein A, B, C, and D are independently carbon atoms or nitrogen atoms are angiotensin II antagonists useful in the treatment of hypertension and congestive heart failure.
Angiotensin II antagonists incorporating a substituted thiophene or furan
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, (2008/06/13)
There are disclosed substituted thiophene and furan derivatives of Formula I which are useful as angiotensin II antagonists. STR1
ANGIOTENSIN II ANTAGONISTS INCORPORATING A SUBSTITUTED PYRIDOIMIDAZOLYL RING
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, (2008/06/13)
Substituted heterocycles attached through a methylene bridge to novel substituted phenyl derivatives of the Formula I are useful as angiotensin II antagonists. STR1
Angiotensin II antagonists incorporating a nitrogen containing six membered ring heterocycle
-
, (2008/06/13)
There are disclosed compounds, containing a pyridine, pyrazine or pyrimidine functionality on the lower ring of Formula I, which are useful as angiotensin II antagonists. STR1
SUBSTITUTED IMIDAZO-FUSED 6-MEMBERED HETEROCYCLCES AS ANGIOTENSIN II ANTAGONISTS
-
, (2008/06/13)
Substituted Imidazo-fused 6-membered heterocycles of structural formula: STR1 wherein A, B, C, and D are independently carbon atoms or nitrogren atoms are angiotensin II antagonists useful in the treatment of hypertension and congestive heart failure.
Nitroketenaminals, VII: Synthesis of substituted 2-amino-3-nitropyridines from 1,3-biselectrophiles and 2-nitroethen-1,1-diamine
Troschutz,Luckel
, p. 785 - 789 (2007/10/02)
The reaction of the enones 1a-f with the nitroketenaminal 2 leads to the 4,6-disubstituted 2-amino-1,4-dihydro-3-nitropyridines 3a-f. Compounds 3a-c,f are oxidized in low yields by air to the pyridines 4a-c,f.-5- and 6-substituted 2-amino-3-nitropyridines (9a,b and 11) can be prepared from 2, 8a,b, and 10, respectively.
ANGIOTENSIN II ANTAGONISTS INCORPORATING AN INDOLE OR DIHYDROINDOLE
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, (2008/06/13)
There are disclosed substituted indoles and dihydroindoles of Formula I which are useful as angiotensin II antagonists. STR1