Example 5. Preparation of 4-(4-cyclopropylnaphthalen-1-yl)-4H-1,2,4-triazole-3-thiols
To a round-bottomed flask was added N-(4-cyclopropyl-1-naphthalenyl)-2-formylhydrazine thiocarboxamide (64.0 g, 225 mmol), N,N-dimethylformamide (300 mL), and 1 mol/L aqueous sodium hydroxide solution (225 mL) to form a mixture. After stirring, the mixture was heated to 30 °C and kept for 16 hours. After the reaction was completed, the mixture was cooled to room temperature (about 20°C). Subsequently, 1 mol/L hydrochloric acid (about 200 mL) was slowly added to the mixture until the pH of the mixture was about 6.0, and then water (about 500 mL) was added. The mixture was stirred for 15 minutes and then filtered. The filter cake was washed with water and the product was dried under vacuum at 50 °C for 5 h to give 4-(4-cyclopropylnaphthalen-1-yl)-4H-1,2,4-triazole-3-thiol as a gray-green solid, 54.0 g in 90% yield.
LC-MS: m/z (ESI): 268 (M + H)+.
1H NMR (400 MHz, acetone-d6): δ 8.57 (d, J = 8.0 Hz, 1H), 8.37 (s, 1H), 7.67 (m, 1H), 7.60 (m, 1H), 7.51 (d, J = 8.0 Hz, 1H), 7.48 (d, J = 8.0 Hz, 1H), 7.43 (d, J = 8.0 Hz, 1H), 2.50 (m, 1H), 1.16 (m, 2H), 0.84 (m, 2H).
