Tetrazole compounds reactions

Tetrazole, l-(p-substituted phenyl)-antimicrobial activity, 5, 835 Tetrazole, 5-thio-rearrangements, 5, 823 Tetrazole, 2-thioacyl-reactions, 5, 109 Tetrazole, 5-(o-tolyl)-tautomerism, 5, 804 Tetrazole, 5-(p-tolyl)-dipole moments, 5, 795 tautomerism, 5, 804 Tetrazole, 5-(trimethylsilylamino)-synthesis, 5, 832 Tefrazolecarbaldehydes reactions, 5, 820 Tetrazole-5-carbaldehydes reactions, 5, 820 Tetrazolecarbonitriles reactions, 5, 820 Tetrazole carbonyl compounds reactions, 5, 820 Tetrazolecarboxylic acid, 5-aryl-acidity, 5, 816... 

Several ring-fused tetrazole compounds have been reported. 2-Methyl-3-cyanopyridines were converted into their corresponding 2-azidomethyl derivatives, which underwent intramolecular cycloaddition reactions to give 3-(tetrazol-5-yl)pyridines 186 <04TL9127>. Fused tetrazole derivatives 187 were obtained via tandem cycloaddition and yV-allylation reactions <04JOC1346>. Expeditive synthesis of homochiral fused tetrazole piperazines 188 from 3-amino alcohols has been reported <04TL3725>. A novel Ugi-five-center-four-component reaction (U-5C-4CR) of aldehydes, primary amines, trimethylsilyl azide and 2-isocyanoethyl tosylate afforded tetrazolopiperazine type compounds <04TL6421>. 

The Mitsunobu reaction has also been employed for the synthesis of substituted tetrazoles. The reaction proceeds via a cyano compound in the presence of trimethylsilyl azide and the DEAD/TTP couple. The activated phosphonium intermediate 238 is thought to react with the azide to give the desired tetrazole derivative. The ethylcyano sidechain on the tetrazole can be removed with 2 N NaOH in THF. ° This reaction has found application in the preparation of tetrazole based growth hormone sccretagogues. ... 

Addition reactions to unsaturated C-glycosides have continued to be utilized to synthesize C-nucleosides. Thus 2,3,5-tri-0-benzoyl-/3-D-ribofuranosyl cyanide with sodium azide-ammonium chloride in DMF gave the tetrazole (72) in 72% yield. Treatment of (72) with acetic anhydride gave the 1,3,4-oxadiazole nucleoside (73). The benzothiazole (74) was obtained from the ribosyl cyanide by reaction with 2-aminothiophenol. Analogous compounds were derived from jS-D-ribo-, 8-D-xylo-, and j3-D-galactopyranosyl cyanides. A similar reaction has been used by a different group to synthesize a-D-arabinosyl tetrazole (75). Reaction of 3,4-di-0-benzoyl-2,5-anhydro-D-... 

Tetrazole compounds are also good starting materials for the synthesis of energetic materials with substituted side-chains attached to the tetrazole skeleton. For example, tetrazole can be alkylated by reaction with l-chloro-2-nitro-2-azapropane and converted into various energetic compounds (Figs. 9.12 and 9.13). 

The 1,3 cycloaddition of NJ (from NH4N3) to nitrile compounds is a convenient method to prepare substituted tetrazoles. The reaction Is normally performed at 373 K In dimethyl-formamide as solvent see e.g. [34 to 36]. 

A comprehensive review of reactions of isocyanates and 1,3-dipolar compounds has been previously pubhshed (51). The example shown illustrates the reaction of azides and isocyanates to yield tetrazoles (14,R = alkyl or aryl, R = aryl or sulfonyl) (52,53). 

Imidazoles and benzimidazoles (155) react with acid chloride and alkali to give compounds of type (157), but these are reactions of the cation (156). 1,2,4-Triazoles and tetrazoles similarly undergo ring opening. 

The addition of isocyanides and azide to aldehyde-derived enamines has led to tetrazoles (533,536). On the other hand the vinylogous amide of acetoacetic ester and related compounds reacted with aldehydes, isocyanides and acids to give a-acylaminoamides (534). Iminopyrrolidones and imino-thiopyrrolidones were obtained from the addition of cyclohexylisocyanide and isocyanates or isothiocyanates to enamines (535). An interesting method for the formation of organophosphorus compounds is found in the reactions of imonium salts with dialkylphosphites (536). 

Ar-Arylbenzimidoyl)tetrazoles t, prepared from JV-arylbenzimidoyl chlorides and 5-(dimethylamino)- or 5-aryltetrazole, give 3//-l,3,4-benzotriazepines 4 on thermolysis. It has been proposed that the reaction proceeds by way of the dipolar compounds 2, which undergo [l,7]-antarafacial 871-electrocyclization to 3. The process is completed by a symmetry-allowed [1.5]-hydrogen shift. Selected examples are given.349-350... 

Several other studies concerning tetrazole-containing compounds were leptorted. The 1-bromo-glycosyl cyanide 15 was converted to the tetrazole derivative 16 in 72% yield by treatment with 2 eq LiNs/DMF/S d <96T9121>. Shorter reaction times led to formation of the 1-azido-pyranosyl cyanide. (Hydroxyphenyl) carbenes could be formed by thermal decomposition of the appropriate 5-substituted tetrazoles 17 <96JOC4462>. 

Nitrous acid or alkyl nitrites react with a number of nitrogen compounds to yield tetrazoles. For example, hydrazidines (87), which can be prepared in situ from the corresponding iminoesters, react with nitrous acid or its derivatives to give 1-substituted tetrazoles (88).150-152 This reaction (Eq. 17), is one of the most extensively used methods for the synthesis of... 

The compounds referred to as azolides are heterocyclic amides in which the amide nitrogen is part of an azole ring, such as imidazole, pyrazole, triazole, tetrazole, benzimidazole, benzotriazole, and their substituted derivatives. In contrast to normal amides, most of which show particularly low reactivities in such nucleophilic reactions as hydrolysis, alcoholysis, aminolysis, etc., the azolides are characterized by high reactivities in reactions with nucleophiles within the carbonyl group placing these compounds at about the same reactivity level as the corresponding acid chlorides or anhydrides. 11... 

Compound 145 on lithiation <1999SM(102)987> and subsequent reaction with carbon dioxide afforded compound 146. Sandmeyer reaction of 2-bromodi thieno[3,2-A2, 3 -with copper(l)cyanide in hot iV-methyl pyrrolidine (NMP) gave the corresponding nitrile 148 which was then converted to the tetrazole 149 with a mixture of sodium azide and ammonium chloride in NMP in low overall yield (Scheme 14) <2001JMC1625>. 

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