- Improved conditions for converting sterically hindered amides to 1,5-disubstituted tetrazoles
-
Improved conditions for converting amides into 1,5-disubstituted tetrazoles are described. The optimum reaction conditions [diisopropyl azodicarboxylate (DIAD), diphenylphosphoryl azide (DPPA), and diphenyl-2-pyridyl phosphine in THF at 45 °C] converted s
- Schroeder, Gretchen M.,Marshall, Sydney,Wan, Honghe,Purandare, Ashok V.
-
experimental part
p. 1404 - 1406
(2010/04/25)
-
- Efficient synthesis of 1,5-disubstituted tetrazoles
-
A general method for the synthesis of 1,5-disubstituted tetrazoles from imidoylbenzotriazoles that involves mild reaction conditions and short reaction times. Georg Thieme Verlag Stuttgart.
- Katritzky, Alan R.,Cai, Chunming,Meher, Nabin K.
-
p. 1204 - 1208
(2008/02/02)
-
- Controlled Synthesis of 5-Substituted 1-Methyl-1H-Tetrazoles and 3,5-Disubstituted 1,4-dimethyltriazolium Salts from N-Methylnitrilium Trifluoromethanesulfonate Salts.
-
C-Alkyl and -benzyl N-methylnitrilium trifluoromethanesulfonate salts, 1C=NMe>+ OTf- (R1=Me, Prn, Pri, But, PhCH2; OTf=O3SCF3), react rapidly under mild conditions with either sodium azide or tetramethylguanidinium azide in nitromethane to give the corresponding 5-substituted 1-methyl-1H-tetrazoles as the sole product in high yields.These reactions are independent of the mode of addition.C-aryl-N-methylnitrilium trifluoromethanesulfonate salts (R1=C6H6, 2-MeC6H4, 4-MeC6H4, 2,4-Me2C6H3) give mixtures of the corresponding tetrazoles and the triazolium salts with sodium azide.With tetramethylguanidinium azide the products depend upon the mode of addition.Addition of the nitrilium salt to the azide gives only the tetrazole, while inverse addition gives the triazolium salt in high yield.
- Amer, Muhanned I. K.,Booth, Brian L.
-
p. 113 - 124
(2007/10/02)
-
- TETRAZOLES. XVI. ALKYLATION OF TETRAZOLES UNDER THE CONDITIONS OF PHASE-TRANSFER CATALYSIS
-
The alkylation of tetrazole and 5-substituted tetrazoles with dimethyl sulfate and methyl iodide in the two-phase methylene chloride-water system in the presence of tetrabutylammonium bromide was investigated.The alkylation of tetrazoles with methyl iodide takes place in the organic phase, while that with dimethyl sulfate takes place both in the organic and in the aqueous phases.The ratio of the isomeric tetrazoles formed during the alkylation of 5-aryltetrazoles by methyl iodide correlate with the substituent constants ?.The use of phase-transfer catalysis during the alkylation of tetrazoles does not lead to a change in the selectivity of the reaction.
- Osipova, T. F.,Ostrovskii, V. A.,Koldobskii, G. I.,Erusalimskii, G. B.
-
p. 357 - 362
(2007/10/02)
-
- A Study of Annular Tautomerism, Interannular Conjugation, and Methylation Reactions of ortho-Substituted-5-aryltetrazoles using Carbon-13 and Hydrogen-1 N.M.R. Spectroscopy
-
In ortho-substituted-5-phenyltetrazoles, Ar-CN4H (Ar = 2'-MeC6H4, 2'-ClC6H4, or 2',6'-Cl2C6H3), the rings are twisted out of the planar configuration and interannular conjugation is inhibited.In each case the tetrazole 1-NH tautomer is strongly predominan
- Butler, Richard N.,Garvin, Victor C.
-
p. 390 - 393
(2007/10/02)
-
- TETRAZOLES. VIII. KINETICS AND RATIO OF THE REACTION PRODUCTS IN THE ALKYLATION OF THE SALTS OF SUBSTITUTED 5-PHENYLTETRAZOLES BY DIMETHYL SULFATE IN ACETONITRILE
-
The kinetics and the ratio of the reaction products were investigated for the alkylation of potassium salts of a series of substituted 5-phenyltetrazoles by dimethyl sulfate in acetonitrile.It was shown that with the salt at a concentration of less than 10-3M the corresponding tetrazolate ion enters into reaction with dimethyl sulfate.Electron-withdrawing substituents in the benzene ring reduce the rate of the alkylation reaction and help to increase the proportion of the N2 isomer in the reaction products.The rate constants for the reaction of substituted 5-phenyltetrazoles with dimethyl sulfate and the ratios of the isomeric tetrazoles formed during alkylation correlate with the ? constants of the substituents.
- Ostrovskii, V. A.,Shirobokov, I. Yu.,Koldobskii, G. I.
-
p. 131 - 135
(2007/10/02)
-