Diethyl Ether → (1-phenyl-1H-1,2,3-triazol-4-yl)methanol

Temperature

90 °C

Phenyl azide (2.02 g, 17.0 mmol) was dissolved in neat propargyl alcohol (3 mL) and the mixture was heated to 90° C. for 2 h. The reaction mixture was cooled to room temperature and the reaction mixture was diluted into diethyl ether and left overnight during which time 7 precipitated as a crystalline solid to afford 1.03 g (35%) of the desired product 7 while the mother liquor contained primarily the regioisomer 9: 1H NMR (400 MHz, CDCl3) δ 7.97, (s, 1H), 7.70, (d, J=8.40 Hz, 2H), 7.50, (m, 2H), 7.41 (m, 1H), 4.88, (d, J=6.00 Hz, 2H), 2.70, (bs, 1H). Step b: Preparation of 1-phenyl-1H-1,2,3-triazole-4-carbaldehyde (9). To a solution of (1-phenyl-1H-1,2,3-triazol-4-yl)methanol, 7, (1.03 g, 5.87 mmol) in CH2Cl2 (50 mL) was added MnO2 (2.05 g, 23.5 mmol). The reaction mixture was stirred for 3 days at room temperature. The reaction mixture was then filtered through Celite© and the resulting filtrate was concentrated in vacuo. The crude material was purified by silica gel chromatography (0-5% methanol/dichloromethane) yielding 0.83 g (82%) of 9: 1H NMR (400 MHz, CDCl3) δ 10.22 (s, 1H), 8.51 (s, 1H), 7.53, (d, J=9.6 Hz, 2H), 7.58-7.49, (m, 3H). Step c: Preparation of N-methyl-N-((1-phenyl-1H-1,2,3-triazol-4-yl)methyl)-5,6,7,8-tetrahydroquinolin-8-amine (Y). To a solution of 1-phenyl-1H-1,2,3-triazole-4-carbaldehyde, 9, (0.23 g, 1.35 mmol) in 1,2-dichloroethane (2 mL) was added N-methyl-5,6,7,8-tetrahydroquinolin-8-amine, 5, (0.20 g, 1.23 mmol), sodium triacetoxyborohydride (0.10 g, 1.60 mmol), and 3 drops of acetic acid. The reaction mixture was stirred for 16 h at room temperature. The reaction mixture was then poured into aqueous saturated NaCl (10 mL) and was extracted with ethyl acetate (10 mL). The organic phase was dried over MgSO4, filtered, and concentrated in vacuo. The crude material was purified by silica gel chromatography (0-5% methanol/dichloromethane) yielding 35 mg (9%) of Y: 1H NMR (400 MHz, CDCl3) δ 8.74 (s, 1H), 8.47 (s, 1H), 7.78, (d, J=8.4 Hz, 2H), 7.50-7.39, (m, 4H), 7.20, (m, 1H), 4.72, (d, J=13.6 Hz, 1H), 4.63-4.58 (m, 2H), 2.90-2.60 (m, 6H), 2.22-2.17 (m, 1H), 2.10-1.95, (m, 1H), 1.90-1.78, (m, 1H).