2-Methyl-8-aminoquinoline (6.36 g, 40.2 mmol, 1 eg.) and TMG-VS (8.25 g, 48.2 mmol, 1.2 eq.) were dissolved in MeCN (100 mL) and triethylamine (11.2 mL, 80.4 mmol, 2 eq.) was added. The reaction mixture was heated to reflux for 30 min under stirring. After cooling to rt a solution of NaOH (1.61 g, 40.2 mmol, 1 eq.) in water (20 ml) was added and the solvent was removed under reduced pressure. An aqueous KOH solution (25 mL, 50 w%) was added and the aqueous layer was extracted with MeCN (3x 100 mL). The combined organic layers were dried over Na2SO4 and filtered. The solvent was removed under reduced pressure and the crude product was distillated in vacuum (<10-1 mbar) starting at 150 °C and increasing the temperature stepwise up to 350 °C. Remained urea was removed in vacuum (<10-1 mbar) at 100 °C. TMG2Mequ was obtained as a yellow oil that turns into a pale yellow solid after a few months (7.51 g, 29.3 mmol, 73%).
