- Alkylation of 5-Substituted 1 H-Tetrazoles via the Diazotization of Aliphatic Amines
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A new alkylation reaction of monosubstituted tetrazoles via the diazotization of aliphatic amines is reported. This method enables preferential formation of 2,5-disubstituted tetrazoles. A one-pot 1,3-dipolar cycloaddition/diazotization sequence starting from widely available nitriles is also described. Azide residues are quenched in the second step with the nitrite reagent, thus limiting the intrinsic risk associated with trimethylsilyl azide. The reaction conditions were compatible with several functional groups, including thiocyanates, which afford preferentially disubstituted 2-alkyl-5-(substituted-thio)tetrazoles.
- Lebel, Hélène,Reynard, Guillaume
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p. 12452 - 12459
(2021/09/07)
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- Application of Photoclick Chemistry for the Synthesis of Pyrazoles via 1,3-Dipolar Cycloaddition between Alkynes and Nitrilimines Generated In Situ
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The photochemical extrusion of gaseous nitrogen from 2,5-disubstituted tetrazoles to generate reactive nitrilimines in situ represents an efficient and attractive way to form dipoles that can be used to provide useful chemicals via 1,3-dipolar cycloadditions. The concept of “photoclick chemistry” already inspired numerous researchers, who exploited photochemical processes involving alkenes for the synthesis of adducts or the functionalization of biocompatible materials. The approach requires bioorthogonality, ease of access to the starting materials and operational simplicity. We report herein our investigations toward a photoclick reaction involving 2,5-disubstituted tetrazoles and alkynes as the dipolarophile for the synthesis of pyrazole derivatives. In addition to the numerous reports recently published on the synthesis of pyrazoles, we wish to add to the list a photochemical procedure that represents a mild and atom-economical alternative. Moreover, considering that such nitrilimines precursors can be accessed in one step from inexpensive and abundant starting materials and given the commercial availability of a broad spectrum of alkynes, we examined the scope of the photoclick reaction with respect to reactive partners, enabling the synthesis of a library of useful heteroaromatics.
- Remy, Richard,Bochet, Christian G.
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p. 316 - 328
(2018/01/27)
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- PREPARATION AND UTILITY OF SUBSTITUTED PHENYLTETRAZOLES
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Disclosed herein are substituted phenyltetrazoles of Formula I, processes of preparation thereof, pharmaceutical compositions thereof, and the methods of their use thereof.
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Page/Page column 46
(2008/12/05)
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- Use of an angiotensin II receptor antagonist for the preparation of drugs to increase the survival rate of renal transplant patients
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The present invention relates to the use, for the preparation of drugs to increase the survival rate of transplant patients, including renal and heart transplant patients, of a therapeutically effective amount of an angiotension II receptor antagonist compound, such as the class of substituted imidazoles represented by formula (I) and in particular by losartan potassium, 2-butyl-4-chloro-[(2′-tetrazol-5-yl)biphenyl-4-il]methyl]-5-(hydroxymethyl)imidazole potassium salt.
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- Tetrazoles: XLIV. Synthesis and chemical properties of 5-substituted 2-triphenylmethyltetrazoles
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Tritylation of tetrazole and its 5-substituted derivatives with triphenylmethyl chloride under conditions of phase-transfer catalysis regioselectively yields the corresponding 5-substituted 2-trityltetrazoles which can be used to protect N-H bonds in nitrogen-containing heterocycles and O-H bonds in primary alcohols. Thermolysis of 2-trityltetrazoles in benzonitrile leads to 3,6-disubstituted 1,2,4,5-tetrazines. Thermal transformation of the same compounds in dodecane follows a radically different mechanism, resulting in formation of difficultly accessible 8,8-diphenylheptafulvenes. The structure of the latter was proved by X-ray analysis.
- Myznikov,Artamonova,Bel'skii,Stash,Skvortsov,Koldobskii
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p. 1360 - 1369
(2007/10/03)
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- INSULIN SENSITIVITY WITH ANGIOTENSIN II RECEPTOR BLOCKING IMIDAZOLES
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This invention relates to a novel method of using an Angiotensin II antagonist for the improvement of insulin sensitivity alone or in conjunction with the treatment of hypertension. Angiotensin II antagonists such as the class of substituted imidazoles represented by formula I: STR1 and specifically by Losartan, 2-butyl-4-chloro-1-[(2'-tetrazol-5-yl)biphenyl-4-yl]methyl]-5-(hydroxymethyl)imidazole potassium salt.
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- Biphenyl substituted dipeptide analogs promote release of growth hormone
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There are disclosed certain compounds identified as substituted dipeptide analogs which promote the release of growth hormone in humans and animals. This property can be utilized to promote the growth of food animals to render the production of edible meat products more efficient, and in humans, to increase the stature of those afflicted with a lack of a normal secretion of natural growth hormone. Growth promoting compositions containing such substituted dipeptide analogs as the active ingredient thereof are also disclosed.
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- Polymorphs of losartan and the process for the preparation of form II of losartan
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Polymorphic forms of Losartan (Formula I) STR1 and a process for the preparation of Form II of Losartan. Losartan is known to be useful in the treatment of hypertension.
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- Treatment of atherosclerosis with angiotensin II receptor blocking imidazoles
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A method of treatment for atherosclerosis and/or reducing cholesterol using an angiotensin II antagonist. This method of treatment can be used in conjunction with the treatment of hypertension. Substituted imidazoles such as STR1 are useful as angiotensin II receptor antagonists for this method of treatment. A method of treatment for atherosclerosis and/or reducing cholesterol using an angiotensin II receptor antagonist in combination with an HMG-Co A reductase inhibitor. A method of treatment for atherosclerosis and/or reducing cholesterol using an angiotensin II receptor antagonist in combination with an HMG-Co A reductase inhibitor and an angiotensin converting enzyme inhibitor. Also within the scope of this invention are pharmaceutical compositions for this method of use.
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- Model reactions targeted at the synthesis of carbon-14 labeled CI-996, a potent antagonist of angiotensin II receptor (1)
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A reaction sequence suitable for the preparation of an analog of 2-propyl-1-[[2'-(1H-tetrazol-5-yl)[1,1'-biphenyl]-4-yl]methyl-4-[2-(tr ifluoroacetyl)-1H-pyrrol-1-yl]-1H-imidazole-5-carboxylic acid, with 14C at the methylene bridge was developed. The would-be labeled fragment (12) was derived from 4-iodobenzenemethanol (6) which itself was constructed from 1,4-dibromobenzene by the application of silicon chemistry. Pd(o) catalyzed coupling of TBDMS protected 6 and a tetrazole borate 10 gave the compound 12 which upon further transformation to the mesylate 13, N-alkylated an imidazole to furnish target compound.
- Ekhato,Huang
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p. 213 - 220
(2007/10/02)
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- Efficient synthesis of losartan, a nonpeptide angiotensin II receptor antagonist
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A highly efficient, convergent approach to the synthesis of the angiotensin II receptor antagonist losartan (1) is described. Directed ortho-metalation of 2-trityl-5-phenyltetrazole provides the key boronic acid intermediate 10 for palladium-catalyzed biaryl coupling with bromide 5 obtained from the regioselective alkylation of the chloroimidazole 2. This methodology overcomes many of the drawbacks associated with previously reported syntheses.
- Larsen,King,Chen,Corley,Foster,Roberts,Yang,Lieberman,Reamer,Tschaen,Verhoeven,Reider,Lo,Rossano,Brookes,Meloni,Moore,Arnett
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p. 6391 - 6394
(2007/10/02)
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- PROCESS FOR PREPARING BIPHENYLTETRAZOLE COMPOUNDS
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Method for the preparing biphenyltetrazole compounds which are angiotensin II receptor antagonists or which are useful intermediates to prepare angiotensin II receptor antagonists. An illustrative biphenyl tetrazole compound is 2-n-butyl-4-chloro-1-[(2'-(tetrazol-5-yl)-1,1'-biphenyl-4-yl)methyl]-1H-imi dazole-5-methanol, potassium salt.
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- Benzo-fused lactams promote release of growth hormone
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There are disclosed certain novel compounds identified as benzo-fused lactams STR1 which promote the release of growth hormone in humans and animals. This property can be utilized to promote the growth of food animals to render the production of edible meat products more efficient, and in humans, to increase the stature of those afflicted with a lack of a normal secretion of natural growth hormone. The compounds are prepared by substitution of an amino-lactam with a substituted amide function. Growth promoting compositions containing such benzo-fused lactams as the active ingredient thereof are also disclosed.
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- N-biphenyl-3-amido substituted benzolactams stimulate growth hormone release
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There are disclosed certain compounds identified as N-biphenyl-3-amido substituted benzolactams which promote the release of growth hormone in humans and animals. This property can be utilized to promote the growth of food animals to render the production
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- Benzo-fused lactams that promote the release of growth hormone
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There are disclosed certain novel compounds identified as benzo-fused lactams which promote the release of growth hormone in humans and animals. This property can be utilized to promote the growth of food animals to render the production of edible meat products more efficient, and in humans, to increase the stature of those afflicted with a lack of a normal secretion of natural growth hormone. Growth promoting compositions containing such benzo-fused lactams as the active ingredient thereof are also disclosed.
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- SUBSTITUTED QUINOLINES AS ANGIOTENSIN II ANTAGONISTS
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Substituted quinolines of the formula (I), are angiotensin II antagonists, STR1 and useful in the treatment of hypertension, ocular hypertension and certain CNS disorders.
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- Tetrazolylphenylboronic acid intermediates for the synthesis of AII receptor antagonists
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Novel tetrazolylphenylboronic acids, methods for their preparation, and their use in the syntheses of angiotensin II receptor antagonists are disclosed.
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- Cycloaddition Reactions of Azide Ligands in Phosphane Complexes of Palladium(II), Platinum(II), and Iridium(I)
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Nitriles are added to the azide ligands of the planar compounds cis-(R3P)2Pt(N3)2 and trans-(Ph3P)2Ir(CO)N3 to give to 5-R-tetrazolato complexes 1 - 3.Kinetic studies show that the rate of the -cycloaddition increases with donor strength of the phosphane ligands and with electron-poor nitriles.The mechanism of the reactions is discussed.Using HCl or acyl chlorides, from 3 and (Ph3P)2Pd(5-R-tetrazolate)2 the free 5-R-tetrazoles or disubstituted tetrazoles are obtained under mild conditions. (Ph3P)2Pd(N3)2 reacts with MeO2CCCCO2Me to give the triazolato complexes 5, 6.Organic isothiocyanates and thiocyanates yield tetrazolinethionato (7) and 5-(methylthio)tetrazolato complexes (8).Using 1H NMR spectroscopy isomeric complexes with these ambidentate heterocyclic ligands can be detected.
- Kreutzer, Peter H.,Weis, Johann Ch.,Bock, Henning,Erbe, Juergen,Beck, Wolfgang
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p. 2691 - 2707
(2007/10/02)
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