184177-81-9

1885-14-9

74853-08-0

184177-81-9

General procedure: 4.00 kg 1-(4-aminophenyl)-4-(4-hydroxyphenyl)piperazine (VII) and 35.57 kg tetrahydrofuran were added to a 100 L glass reactor, stirring was turned on, and the reaction was cooled down to 0 to 10°C. The reaction temperature was controlled at 0.5 to 1 hour. 2.56 kg of phenyl chloroformate (VIII) was slowly added dropwise for 0.5 to 1 h at a temperature lower than 25 °C, the reaction temperature was controlled at 20 to 25 °C, and the reaction was continued for 0.5 to 1.0 h after the dropwise addition. The reaction process was monitored by TLC. After completion of the reaction, the reaction solution was cooled to 0 to 10°C, a saturated aqueous sodium bicarbonate solution prepared by dissolving 2.00 kg of sodium bicarbonate in 38 kg of purified water was added, another 20 kg of purified water was added, and the reaction was stirred for 10 to 20 minutes. The reaction mixture was centrifuged through a filter until the filtrate was neutral and no solvent remained, followed by rinsing with 8 kg of purified water and centrifuging again until the filtrate was neutral and no solvent remained. The resulting wet product was dried under reduced pressure under vacuum of -0.06 MPa to -0.1 MPa and at a temperature of 40 to 50 °C for 12 to 16 h to obtain 5.47 kg of gray solid, i.e., phenyl (4-(4-(4-hydroxyphenyl)-1-piperazinyl)phenyl)carbamate (V); the purity of the HPLC was 98.5% and the yield was 94.6%.