Short-RInChIKey=SA-FUHFF-UHFFFADPSC-PJLMQMBEXP-UHFFFADPSC-NUHFF-NUHFF-NUHFF-ZZZ

The experiment was carried out using Schlenk technique with nitrogen (99.996%, dried over phosphorus pentoxide) as inert gas. 2-Aminobenzylamine (13.90 g, 113.8 mmol, 1 eq.) and triethylamine (31.70 mL, 23.01 g, 227.4 mmol, 2 eq.) were added to acetonitrile (100 mL) and stirred in an ice bath (0 °C). Chloro-N,N,N',N'-tetramethylformamidinium chloride  (38.92 g, 227.5 mmol, 2 eq.) dissolved in acetonitrile (250 mL) was added dropwise. Subsequently, the colorless suspension was refluxed over the course of five hours. After cooling to room temperature (20 °C), an aqueous solution of sodium hydroxide (9.10 g, 227.5 mmol, 2 eq. in 80 mL of water) was added and acetonitrile, water and triethylamine were removed under reduced pressure (p = 0.05 mbar). The following extraction and filtration were performed at ambient conditions (air atmosphere, no Schlenk technique used). The oily, yellow residue was dissolved in an aqueous solution of potassium hydroxide (50 wt%, 40.00 g in 40.00 ml water) and extracted with acetonitrile (4 x 100 mL). The combined organic phases were dried over magnesium sulfate and filtered over Celite before the solvent was removed under reduced pressure (p = 0.05 mbar).Fractional distillation under nitrogen atmosphere (p = 0.05 mbar, T(oilbath) = 240 °C, T(head) = 140 °C) resulted in the target compound, 2-(2((bis(dimethylamino)methyl-ene)amino)benzyl)-1,1,3,3-tetramethylguanidine, as a light yellow oil (27.30 g, 85.7 mmol, 75 %). Single crystals suitable for x-ray diffraction were grown from a concentrated pentane solution. The solution was heated up until it became turbid and was placed in a freezer (-30 °C) for five days afterwards.