(1H-Benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate 125700-67-6 Benzotriazol-1-yl-tetramethyluronium tetrafluoroborate Btttfb Methanaminium, N-((1H-benzotriazol-1-yloxy)(dimethylamino)methylene)-N-methyl-, tetrafluoroborate(1-)