Herein, we report an unprecedented synthesis of a new class of di-heteroarylmethanes, i.e., bis(pyrazolo[1,5-a]pyrimidin-3-yl)methanes from pyrazolo[1,5-a]pyrimidines using DMSO as the C1 synthon (methylene source). The transformation was mediated by sodium metabisulfite (Na2S2O5), which played a crucial role, in the presence of acetic acid as a promoter. A wide variety of bis(pyrazolo[1,5-a]pyrimidin-3-yl)methanes were synthesized in moderate to good yield up to 90%. Mechanistic studies suggested that the reaction followed an ionic pathway, most probably involving methyl(methylene)sulfonium ion as the active electrophilic species, formed in situ by the reaction between DMSO and Na2S2O5.