Biphenyltetrazole group, an important component of sartans, is usually formed in excellent yield by the reaction of 4′-alkylbiphenyl-2-carbonitrile with excessive organotin azide. However, it is restricted in industrial scale because of the difficult post-treatment. In this article, an improved synthetic method for valsartan and the quantitative recovery of tri-n-butyltin chloride are reported. During this process, the tetrazole–Sn complex and excessive organotin azide were decomposed by HCl to furnish tri--n-butyltin chloride, and then reacted with NaF to lead to filterable polymer tributyltin fluoride which was converted again to tributyltin chloride by HCl in ethyl acetate. This approach is facile for the efficient manufacture of sartans using organotin azide to form the tetrazole group and is valuable for industry readers.

The title mol­ecule, C20H20N2, is chiral; the absolute configuration follows from the known chirality of the input reagents. In addition to van der Waals forces, C—H⋯π ring inter­actions are also present. The angle between the planes of the phenyl rings is 65.6 (1)°. The heterocyclic ring of the quinoxaline system has a twist-boat configuration, while the cyclohexane ring has a chair configuration.

A convenient three-step preparation of the dinucleating ligand, 1,6-bis(2-furyl)-2,5-bis(2-hydroxy-3-formyl-5-methylbenzyl)-2,5-diazahexane (3) starting from 2,6-bis(hydroxymethyl)-4-methylphenol (4) is reported. Compound 4 was partially oxidized with preactivated manganese dioxide to form compound 5, which was converted to 2-hydroxy-3-chloromethyl-5-ethylbenzaldehyde (6) with conc.HCl/EtOH. Compound 6 in turn reacted with N,N’-bis (2-furyl)-1,2-diaminoethane (7) in the presence of K2CO3 in ethanol to give the title compound 3. No protecting groups were required in the whole process and the conditions were mild.

The two in situ 2 + 3 intermolecular cycloaddition reactions between inorganic complexes bis(3-cyanopyrdine)copper(II)azide (A) offer homometallic and heterometallic 3D novel tetrazole coordination polymers, (3-C 5 H 4 N-CN 4 ) 2 Cu(I) 2 (1) and (3-C 5 H 4 N-CN 4 )Cu(I)Cd(II)Cl 2 (2), respectively, in the presence of Lewis acid CuCl 2 and CdCl 2 in which A is used to replace the organic cyano group and NaN 3 during Sharpless's tetrazole synthesis. Their interesting luminescent properties are reported.