185619-66-3

24424-99-5

54060-30-9

185619-66-3

Step a) Synthesis of tert-butyl (3-ethynylphenyl)carbamate: 3-ethynylaniline (25.0 g, 213 mmol) and di-tert-butyl dicarbonate (93.1 g, 427 mmol) were dissolved in THF (427 mL) and the reaction was heated at 70 °C overnight. After the reaction was completed, it was cooled to room temperature, 3-dimethylamino-1-propylamine (32.1 g, 320 mmol) was added and stirred at room temperature for 1 hour. The reaction mixture was concentrated, extracted with ether and washed sequentially with 1N HCl, saturated saline, saturated sodium bicarbonate solution and saturated saline. The organic layer was dried with anhydrous sodium sulfate and concentrated under reduced pressure to afford the target product tert-butyl (3-alkynylphenyl)carbamate (45.0 g, 97% yield). The structure of the product was confirmed by NMR and mass spectrometry.