Triazene compounds with the regio-isomeric form 18 could not be reacted (see Supporting Information, Scheme S1) even after extended reaction times, only starting material was reisolated, presumably due to the increased stability of isomer 18 towards acids. This corresponds with the results for the previously reported triazene cleavage to diazonium intermediates and subsequent cyclization to triazine derivatives. Scheme 2: Synthesis of pyrazoloazides 19a-v via cleavage of the protecting triazene moiety.