General procedure for the synthesis of 2-ethynyl-4-methylaniline from the compound (CAS: 180624-14-0): to a stirred 2:1 MeOH/Et2O (250 mL) solution of 2-ethynyl-4-methylaniline (22) (11.32 g, 55.6 mmol) was added, at room temperature, K2CO3 (15.38 g, 111 mmol ). After stirring at this temperature for 1 h, the reaction mixture was diluted with water and extracted with CH2Cl2. The organic layer was dried over MgSO4, filtered and concentrated under reduced pressure to afford 2-alkynyl-4-methylaniline (23) as a light brown solid without further purification (6.79 g, 93%).1H NMR (300 MHz, CDCl3) δ 7.14 (d, J = 1.5 Hz, 1H), 6.96 (dd, J = 8.2, 1.5 Hz, 1H), 6.62 (d, J = 8.2, 1.5 Hz, 1H) 6.62 (d, J = 8.2 Hz, 1H), 4.11 (s, 2H), 3.36 (s, 1H), 2.21 (s, 3H).