Tetrazole amino-substituted

Other amino substituted isoxazoles undergo ring-opening reactions on treatment with base. Thus the amidine derivative (249) gave the triazole (250) (64TL149), while the triazene (251) on reaction with ammonia gave the tetrazole (252) (64X461). 

An alternative approach to 5-5 bicyclic fused ring systems utilizing a condensation reaction was described by Moderhack et al. <2000JPC591> (Scheme 10). The amino-substituted tetrazole derivatives 52 and 54 gave the neutral 53 as well as the mesoionic derivatives 55 in moderate to excellent yields (16-86% R = CH3 or Ph). 

The fused tetrazoles 10 containing various aryl groups in position 6 were boiled in acetic acid in the presence of either triphenylphosphine or copper and gave rise to the amino-substituted triazines 12. The reaction proceeds obviously via valence bond isomerization of 10 to the azide 11 and is regarded as a useful synthetic route to the diamino compounds 12. 

Many substituted alkyl-, dialkyl-, aryl-, alkylaryl-, etc compds are described in the literature, for instance, metbylaminotetrazole, which is described as 5-amino- 1-methyl-a-tetrazole. Other substituted 5-aminotetrazoies,... 

Direct irradiation of amino substituted azirines leads to neutral nitrile ylides which can be trapped with electron-deficient double bonds. H. Heimgartner described the synthesis of triazolines and oxazolines via trapping of a nitrile ylide with diethylazodicarboxylate and methyl trifluoroacetate, respectively. An elegant application of 1,3-dipolar cycloaddition chemistry is the photolysis of a tetrazole leading to a reactive nitrile imine which is trapped in an intramolecular fashion. 

Chowdari and Barbas [22] reported the enantioselective total synthesis of potent cell adhesion inhibitor BIRT-377 (56) in 2005, which has potential for the treatment of a number of inflammatory and immune disorders. Asymmetric synthesis of quaternary amino acids is a challenging task for synthetic chemists [23]. Barbas described the efficient L-proUne-derived, tetrazole-catalyzed direct asymmetric a-amination to construct an aldehyde 55 with the amino-substituted quaternary stereocenter and elaborate this aldehyde into BIRT-377 (56) (Scheme 17.7). 

UV spectra, 5, 798 synthesis, 5, 833 thermolysis, 5, 812 Tetrazole, 5-amino-2-methyl-methylation, 5, 818 Tetrazole, 2-aryl-5-substituted quatemization, 5, 815 Tetrazole, 5-aryl-acidity, 5, 816... 

A very similar rearrangement has been reported for the conversion of 5-amino-l,2,3,4-tetrazole (4) into the 5-(substituted amino)-l,2,3,4-tetra-zole (5) and vice versa (Scheme IV.6) [53JOC779 53JOC1283 54JA88 71JCS(CC)674]. The reaction proceeds via the intermediacy of an azido-... 

A library of piperazine containing fused azepine-tetrazoles 183 was built by Nixey et al. via Ugi reaction in the solution phase [55]. This library comprises an example of a building block introduced piperazine (Scheme 32). The reaction of A-Boc-a-amino aldehyde 184, methyl isocyanoacetate 185, substituted piperazines 186, and trimethylsilylazide 181 in methanol, followed by acid treatment, proton scavenging, and reflux affords bicyciic azepine-tetrazoles 183. This efficient protocol with three diversity points can be used to generate arrays of biologically... 

Treatment of 5-substituted amino-1,2,3,4-thiatriazoles (546) with aqueous base results in competitive rearrangement to 5-thiotetrazoles (547) and fragmentation to isothiocyanates (548) and azide ion (67JOC3580). The use of solid Ba(OH)2 suspended in toluene containing HMPA has given 80% yield of tetrazole (547). 

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