14832-56-5Relevant articles and documents
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.
Tandem regioselective synthesis of tetrazoles and related heterocycles using iodine
Yella, Ramesh,Khatun, Nilufa,Rout, Saroj Kumar,Patel, Bhisma K.
, 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.