Tetrazolyl substituted

In general, tetrazolium salts are stable in mineral acids. This stability has allowed a number of synthetic transformations such as ester and amide hydrolysis and demethylation of ethers etc.209-212 This is not the case with tetrazolium salts containing a heterocyclic substituent in the 3-position. They tend to decompose in mineral acid to the corresponding tetrazoles.230 Tetrazolyl-substituted tetrazoliums (146) and mesoionic tetrazoles, e.g., 145, are unaffected by acids.228,232... 

Heating the tetrazolyl-substituted verdazyl (139) in boiling acetone afforded the tricyclic system (140) (77KGS557). 

The acidity of tetrazolyl-substituted carboxylic acids has been discussed in several publications. For example, the pA"a values of tetrazolylacetic acids 161-163 in water were reported <2006RJ01585>. In tetrazolylacetic acid 161 with two centers capable of ionization, only the carboxy group possesses high acidity. 

Stille JK, Chen AT (1971) Synthesis and copolymerization of tetrazolyl substituted styrenes. Thermal crosslinking of copolymers containing dipolarophiles and the tetrazole dipole precursor. Polymer Prepr 12 1... 

Hydrolysis of trifluoromethyl group was accomplished in a different type of substrates, namely, tetrazolyl-substituted pyrimidines 1220 affording pyrimidine carboxylic acids 1221 (Scheme 265) [471]. Although support from the tetrazolyl moiety was stated, no explanation for this effect was proposed by the authors. 

Fischer GW (1993) Tetrazole compounds. 8. Synthesis of tetrazolylpyrimidines from tetrazolyl-substituted eneunino ketones. J Heterocycl Chem 30 1517-1520... 

Reaction of 8-substituted 3-[2-(4-methoxybenzyl)-2//-tetrazol-5-yl]-4//-pyrido[l,2-u]pyrimidin-4-ones with CF3COOH for 2 days at room temperature gave 3-(2//-tetrazol-5-yl) derivatives (OlMIPl). The cyano group of a 3-(8-substituted 2-hydroxy-4-oxo-4//-pyrido[l,2-u]pyrimidin-3-yl)-2-propenenitrile was converted into a 5-tetrazolyl group by treatment with NaN3 in the presence of AICI3 in DMF at 100 °C for 2 days. 

The prepn of a variety of 3,5-diatyl-l-(5 -tetrazolyl)(lH) tetrazolium betaines by introducing electronegative substituents in the benzene residue of l-fS -tecrazolyl) -phenyltetrazene, together with the use of substituted benzaldehydes is reported (Ref 3) Refs 1) J.P. Horwitz V.A. Grakauskas, JOrgChem 19, 194-201 (1954) CA 49, 3173 (1955) 2) Ibid, JACS 77, 6711 (1955) CA... 

Tetrazolyl)-4//-pyrido[l,2-a]pyrimidin-4-ones 441 were alkylated with alkyl iodides, alkyl bromides, triethyl phosphate, cyclopentyl bromide, allyl bromide, propargyl bromide, benzyl chlorides, ethyl bromoace-tate, and methyl chloroformate in dimethylformamide in the presence of potassium carbonate at 80-90°C to give a mixture of 3-(l-substituted 5-tetrazolyl)- and 3-(2-substituted 5-tetrazolyl)-4//-pyrido[l,2-u]pyrimidin-... 

Thermolysis of )8-substituted o -(l-tetrazolyl)acrylamides (166) in the presence of copper gives 2,4-disubstituted imidazole-5-carboxamides. Since, however, the side chain is incorporated in the new ring, this might be better classified as a reaction in which the 1,5- or 3,4-bond is formed (Scheme 93) <80AHC(27)241>. 

The dithiazole 58 is converted into the imidazodithiazole 59 and the imidazolethione 60 by a photochemical reaction of unknown mechanism (Eq. 18). Thermolysis of the ( -substituted a-(l-tetrazolyl)acrylamides 61 in the presence of copper has been reported to give 2,4-disubstituted imidazole-5-carboxamides (Eq. 19). 

To determine the a constants for the 5-tetrazolyl group, Shchipanov used correlations linking the acid-base properties of 5-substituted tetrazoles with a constants for substituents regarding a 5-tetrazolyl group as one of the substituents (5,5 -ditetrazolyl) (83KGS1130). In the work of Kaczmarek et al. the a constants for the 5-tetrazolyl group are determined by means of pK, values of substituted phenyltetrazolyl acids, as well as by IR, UV, and PMR... 

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