14832-56-5Relevant academic research and scientific papers
Eco-efficient one-pot tandem synthesis of 1-aryl-1H-tetrazol-5-amine by CAN via in situ generated 1-phenylthiourea and heterocumulene
Kondhare, Dasharath D.,Bhadke, Venkat V.,Deshmukh, Sushma S.,Wakhradkar, Mahesh G.,Totawar, Balaji B.
, (2021/07/28)
A simple, cost-effective, environmentally benign, and efficient one-pot tandem approach to the synthesis of pharmaceutically important 1-aryl-1H-tetrazole-5-amines 3a-k and 4a-k has been described. The reaction utilized 1-phenyl thiourea, which was generated in situ from aqueous ammonia and isocyanates 1a-k, for the formation of heterocumenes using sodium azide, triethylamine, and ceric ammonium nitrate (CAN) to obtain various aryl-substituted 1H-tetrazole-5-amines (3a-k) in good to excellent yields.
Green chemistry: ZrOCl2·8H2O catalyzed regioselective synthesis of 5-amino-1-aryl-1H-tetrazoles from secondary arylcyanamides in water
Khalili, Behzad,Darabi, Faramarz Sadeghzadeh,Eftekhari-Sis, Bagher,Rimaz, Mehdi
, p. 1569 - 1572 (2013/10/22)
A green and efficient method for the synthesis of 5-amino-1-aryl-1H- tetrazoles with excellent yields and high purity from secondary arylcyanamides is described. This method is completely green because no organic solvents or protic acid catalyst is used t
Tandem regioselective synthesis of tetrazoles and related heterocycles using iodine
Yella, Ramesh,Khatun, Nilufa,Rout, Saroj Kumar,Patel, Bhisma K.
experimental part, p. 3235 - 3245 (2011/06/20)
A one-pot, tandem process has been developed for the synthesis of a library of tetrazoles from aryl isothiocyanates. Condensation of aryl isothiocyanates with ammonia, and aryl amines (R-NH2) provided mono, 1,3-disubstituted symmetrical and unsymmetrical thioureas, which on desulfurization with molecular iodine (I2) led to formation of the corresponding heterocumulene (cyanamides or carbodiimides). The in situ generated heterocumulene on subsequent treatment with sodium azide at room temperature gave corresponding tetrazoles. The product regioselectivity for unsymmetrical 1,3-disubstituted thioureas was found to be correlated with the basicities (pKa's) of the parent amines attached to the thiourea. Aryl-sec-alkyl unsymmetrical thioureas gave thioamido guanidino products rather than the 5-aminotetrazoles produced by HgCl2 mediation of the reaction. Bis-thioureas derived from aryl isothiocyanates and hydrazine gave thiadiazoles exclusively.
On the Physicochemical Characterization of 5-Amino-1-aryl-1H-tetrazoles: Electronic Molecule Parameters from the Thermal Isomerization into 5-Arylamino-1H-tetrazoles
Schelenz, Thomas,Schaefer, Wieland
, p. 197 - 200 (2007/10/03)
The known thermal isomerization of 5-amino-1-aryl-1H-tetrazoles (A) into corresponding 5-arylamino-1H-tetrazoles (HB) was used to derive physicochemical parameters characterizing the electronic substituent effect on isomerism and dissociation equilibria. For a series of 26 tetrazoles A as starting materials the equilibrium constants (pKi) of isomerization in boiling ethylene glycol at 197°C and the dissociation constants (pKa) of the NH-acidic tetrazoles HB were determined by potentiometric titration of rapidly cooled equilibrium mixtures in water and ethanol/water with KOH at 25°C. The pK values are closely correlated with Hammett's electronic substituent constants σ and can be used as electronic molecule parameters in QSAR or QSPR (QSAR = quantitative structure-activity relationship; QSPR = quantitative structure-property relationship) studies.
