4′-Methylbiphenyl-2-tetrazole (HMBT) is an important intermediate to the synthesis of Valsartan while HMBT is obtained by the decomposition of Zn-complex (organic–inorganic polymer) containing HMBT. This is the first example of crystallographic characterization of Zn-complex with HMBT produced during in situ [2+3] cycloaddition between 4-methylbiphenyl-2-carbonitrile (MBC) and NaN3 in the presence of ZnCl2. Also, crystal structural determinations of HMBT and impurity produced during hydrothermal hydrolysis reaction of MBC were reported.