N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, property shared the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, solid at room temperature making it one of few known solids. The crystal structure was determined by single-crystal X-ray diffraction and compared that other previously described pyropho...