73565-27-2

Upstream product

• 2059-75-8 N,N'-bis(p-bromophenyl)thiourea 
• 106-40-1 4-bromo-aniline 
• 1985-12-2 4-Bromophenyl isothiocyanate 
• 3988-03-2 bis(4-bromophenyl)methanone 

Relevant academic research and scientific papers

Construction of 5-Aminotetrazoles via in Situ Generation of Carbodiimidium Ions from Ketones Promoted by TMSN3/TfOH

A novel synthetic approach for the synthesis of 5-aminotetrazoles has been developed by employing simple ketones as substrates. This methodology involved the N2-extrusion/aryl migration of azido complexes as the key step for the in situ generation of carbodiimidium ion, which could further react with hydrazoic acid and cyclize intramolecularly to provide 5-aminotetrazoles in good to excellent yields. In addition, the regioselectivity of the reaction was studied and rationalized by density functional theory calculations.

Palladium catalyzed carbonylative annulation of the C(sp2)-H bond of N,1-diaryl-1H-tetrazol-5-amines and N,4-diaryl-4H-triazol-3-amines to quinazolinones

Pd(ii) catalyzed direct C-H carbonylative annulation of N,1-diaryl-1H-tetrazol-5-amines and N,4-diaryl-4H-1,2,4-triazol-3-amines gave the corresponding triazole and tetrazole fused quinazolinones in good yields. This methodology offers a convenient method for the synthesis of these important heterocyclic scaffolds in a highly atom economical process. On the mechanistic aspect weakly nucleophilic triazole and tetrazole moieties function as both directing as well as intramolecular nucleophiles. The catalytically active C-H activated intermediate dimeric Pd complex was isolated and characterized which on exposure to CO gas gave the corresponding tetrazole fused quinazolinone derivative. On the basis of isolation of the intermediate and observed kinetic isotope effects, a mechanism has been proposed for the C-H activated direct carbonylative annulation reaction.

Water promoted one pot three-component synthesis of tetrazoles

A one pot, three component synthesis of tetrazoles via thiourea has been accomplished in water. Water enhances the solubility of a higher number of components in the three component protocol thus promoting the reaction. The synthesis involves a chemoselective exocyclic reaction, regioselective electrocyclisation and a preferred conformational orientation of the tetrazole side chain which are rationalised based on the relative magnitude of Garbisch angle strain/allylic strains anticipated during the course of the reaction.

An expedient route to the azoles through oxidative desulfurization using iodine reagent

A novel and expedient regioselective method for the synthesis of 5-aminotetrazoles and 3-amino-1,2,4-triazoles through oxidative desulfurization of corresponding 1,3-disubstituted thioureas has been discovered and optimized for the process conditions. The process is broadly applicable to structurally diverse 1,3-disubstituted thioureas.

Tandem regioselective synthesis of tetrazoles and related heterocycles using iodine

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.